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Yu S, Gu X, Zheng Q, Liu Y, Suhas T, Du W, Xie L, Fang Z, Zhao Y, Yang M, Xu J, Wang Y, Lin MH, Pan X, Miner JH, Jin Y, Xie J. Tauroursodeoxycholic acid ameliorates renal injury induced by COL4A3 mutation. Kidney Int 2024:S0085-2538(24)00334-X. [PMID: 38782199 DOI: 10.1016/j.kint.2024.04.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2023] [Revised: 03/17/2024] [Accepted: 04/25/2024] [Indexed: 05/25/2024]
Abstract
COL4A3/A4/A5 mutations have been identified as critical causes of Alport syndrome and other genetic chronic kidney diseases. However, the underlying pathogenesis remains unclear, and specific treatments are lacking. Here, we constructed a transgenic Alport syndrome mouse model by generating a mutation (Col4a3 p.G799R) identified previously from one large Alport syndrome family into mice. We observed that the mutation caused a pathological decrease in intracellular and secreted collagen IV α3α4α5 heterotrimers. The mutant collagen IV α3 chains abnormally accumulated in the endoplasmic reticulum and exhibited defective secretion, leading to persistent endoplasmic reticulum stress in vivo and in vitro. RNA-seq analysis revealed that the MyD88/p38 MAPK pathway plays key roles in mediating subsequent inflammation and apoptosis signaling activation. Treatment with tauroursodeoxycholic acid, a chemical chaperone drug that functions as an endoplasmic reticulum stress inhibitor, effectively suppressed endoplasmic reticulum stress, promoted secretion of the α3 chains, and inhibited the activation of the MyD88/p38 MAPK pathway. Tauroursodeoxycholic acid treatment significantly improved kidney function in vivo. These results partly clarified the pathogenesis of kidney injuries associated with Alport syndrome, especially in glomeruli, and suggested that tauroursodeoxycholic acid might be useful for the early clinical treatment of Alport syndrome.
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Affiliation(s)
- Shuwen Yu
- Department of Nephrology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Institute of Nephrology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xiangchen Gu
- Department of Nephrology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Institute of Nephrology, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Department of Nephrology, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Qimin Zheng
- Department of Nephrology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Institute of Nephrology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yunzi Liu
- Department of Nephrology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Institute of Nephrology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Teija Suhas
- Division of Nephrology, Department of Medicine and Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Wen Du
- Department of Nephrology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Institute of Nephrology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Lin Xie
- Department of Nephrology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Institute of Nephrology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zhengying Fang
- Department of Nephrology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Institute of Nephrology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yafei Zhao
- Department of Nephrology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Institute of Nephrology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Mingxin Yang
- Department of Nephrology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Institute of Nephrology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jing Xu
- Department of Nephrology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Institute of Nephrology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yimei Wang
- Department of Nephrology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Institute of Nephrology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Meei-Hua Lin
- Division of Nephrology, Department of Medicine and Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Xiaoxia Pan
- Department of Nephrology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Institute of Nephrology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jeffrey H Miner
- Division of Nephrology, Department of Medicine and Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Yuanmeng Jin
- Department of Nephrology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Institute of Nephrology, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - Jingyuan Xie
- Department of Nephrology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Institute of Nephrology, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
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Puapatanakul P, Isaranuwatchai S, Chanakul A, Surintrspanont J, Iampenkhae K, Kanjanabuch T, Suphapeetiporn K, Charu V, Suleiman HY, Praditpornsilpa K, Miner JH. Quantitative assessment of glomerular basement membrane collagen IV α chains in paraffin sections from patients with focal segmental glomerulosclerosis and Alport gene variants. Kidney Int 2024; 105:1049-1057. [PMID: 38401706 PMCID: PMC11032260 DOI: 10.1016/j.kint.2024.01.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2023] [Revised: 01/05/2024] [Accepted: 01/12/2024] [Indexed: 02/26/2024]
Abstract
Focal segmental glomerulosclerosis (FSGS) lesions have been linked to variants in COL4A3/A4/A5 genes, which are also mutated in Alport syndrome. Although it could be useful for diagnosis, quantitative evaluation of glomerular basement membrane (GBM) type IV collagen (colIV) networks is not widely used to assess these patients. To do so, we developed immunofluorescence imaging for collagen α5(IV) and α1/2(IV) on kidney paraffin sections with Airyscan confocal microscopy that clearly distinguishes GBM collagen α3α4α5(IV) and α1α1α2(IV) as two distinct layers, allowing quantitative assessment of both colIV networks. The ratios of collagen α5(IV):α1/2(IV) mean fluorescence intensities (α5:α1/2 intensity ratios) and thicknesses (α5:α1/2 thickness ratios) were calculated to represent the levels of collagen α3α4α5(IV) relative to α1α1α2(IV). The α5:α1/2 intensity and thickness ratios were comparable across all 11 control samples, while both ratios were significantly and markedly decreased in all patients with pathogenic or likely pathogenic Alport COL4A variants, supporting validity of this approach. Thus, with further validation of this technique, quantitative measurement of GBM colIV subtype abundance by immunofluorescence, may potentially serve to identify the subgroup of patients with FSGS lesions likely to harbor pathogenic COL4A variants who could benefit from genetic testing.
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Affiliation(s)
- Pongpratch Puapatanakul
- Division of Nephrology, Department of Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand; Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Suramath Isaranuwatchai
- Division of Nephrology, Department of Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand; Division of Nephrology, Department of Internal Medicine, Chulabhorn Hospital, Chulabhorn Royal Academy, Bangkok, Thailand
| | - Ankanee Chanakul
- Division of Nephrology, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Jerasit Surintrspanont
- Department of Pathology, King Chulalongkorn Memorial Hospital, The Thai Red Cross Society, Bangkok, Thailand; Special Task Force for Activating Research, Department of Pathology, Chulalongkorn University, Bangkok, Thailand
| | - Kroonpong Iampenkhae
- Department of Pathology, King Chulalongkorn Memorial Hospital, The Thai Red Cross Society, Bangkok, Thailand
| | - Talerngsak Kanjanabuch
- Division of Nephrology, Department of Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand; Center of Excellence in Kidney Metabolic Disorders, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Kanya Suphapeetiporn
- Division of Medical Genetics and Metabolism, Center of Excellence for Medical Genomics, Department of Pediatrics, Medical Genomic Cluster, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand; Excellence Center for Genomics and Precision Medicine, King Chulalongkorn Memorial Hospital, The Thai Red Cross Society, Bangkok, Thailand
| | - Vivek Charu
- Department of Pathology, Institute of Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, California, USA
| | - Hani Y Suleiman
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Kearkiat Praditpornsilpa
- Division of Nephrology, Department of Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Jeffrey H Miner
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA.
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Fujimaru T, Mori T, Chiga M, Mandai S, Kikuchi H, Ando F, Mori Y, Susa K, Nakano Y, Shoji T, Fukudome Y, Inaba N, Kitamura K, Nakanishi T, Uchida K, Kimura T, Tamura T, Ozawa K, Uchida S, Sohara E. Genetic Diagnosis of Adult Hemodialysis Patients With Unknown Etiology. Kidney Int Rep 2024; 9:994-1004. [PMID: 38765603 PMCID: PMC11101786 DOI: 10.1016/j.ekir.2024.01.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 12/20/2023] [Accepted: 01/15/2024] [Indexed: 05/22/2024] Open
Abstract
Introduction Kidney disease of unknown etiology accounts for 1 in 10 adult end-stage renal disease (ESRD) cases worldwide. The aim of this study is to clarify the genetic background of patients with chronic kidney disease (CKD) of unknown etiology who initiated renal replacement therapy (RRT) in adulthood. Methods This is a multicenter cross-sectional cohort study. Of the 1164 patients who attended 4 dialysis clinics in Japan, we first selected patients who started RRT between the ages of 20 and 49 years. After excluding patients with apparent causes of CKD (e.g., diabetic nephropathy, polycystic kidney disease (PKD) with family history, patients who underwent renal biopsy), 90 patients with CKD of unknown cause were included. The 298 genes associated with CKD were analyzed using capture-based targeted next-generation sequencing. Results Of the 90 patients, 10 (11.1%) had pathogenic variants in CKD-causing genes and 17 (18.9%) had variant of unknown significance (VUS). Three patients had PKD1 pathogenic variants, and 1 patient had PKD1 and COL4A4 pathogenic variants. In addition, 2 patients were diagnosed with atypical hemolytic uremic syndrome (aHUS) due to C3 or CFHR5. One patient each was diagnosed with Alport syndrome due to COL4A4 and COL4A3 variants, nephronophthisis due to NPHP1 variants, Fabry disease due to GLA variants, and autosomal-dominant tubulointerstitial kidney disease due to UMOD variants. Genetic diagnoses were not concordant with clinical diagnoses, except for patients with PKD1 variant. Conclusion This largest study on genetic analysis in hemodialysis-dependent adults revealed the presence of undiagnosed inherited kidney diseases.
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Affiliation(s)
- Takuya Fujimaru
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Takayasu Mori
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Motoko Chiga
- Clinical Laboratory, Tokyo Medical and Dental University (TMDU) Hospital, Tokyo Japan
| | - Shintaro Mandai
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Hiroaki Kikuchi
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Fumiaki Ando
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Yutaro Mori
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Koichiro Susa
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Yuta Nakano
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | | | | | - Naoto Inaba
- Kitakurihama Takuchi Clinic, Yokosuka, Japan
| | | | | | | | | | | | | | - Shinichi Uchida
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Eisei Sohara
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
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Wang SX, Streit A. Shared features in ear and kidney development - implications for oto-renal syndromes. Dis Model Mech 2024; 17:dmm050447. [PMID: 38353121 PMCID: PMC10886756 DOI: 10.1242/dmm.050447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2024] Open
Abstract
The association between ear and kidney anomalies has long been recognized. However, little is known about the underlying mechanisms. In the last two decades, embryonic development of the inner ear and kidney has been studied extensively. Here, we describe the developmental pathways shared between both organs with particular emphasis on the genes that regulate signalling cross talk and the specification of progenitor cells and specialised cell types. We relate this to the clinical features of oto-renal syndromes and explore links to developmental mechanisms.
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Affiliation(s)
- Scarlet Xiaoyan Wang
- Centre for Craniofacial and Regenerative Biology, King's College London, London SE1 9RT, UK
| | - Andrea Streit
- Centre for Craniofacial and Regenerative Biology, King's College London, London SE1 9RT, UK
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5
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Tong J, Zheng Q, Gu X, Weng Q, Yu S, Fang Z, Jafar Hussain HM, Xu J, Ren H, Chen N, Xie J. COL4A3 Mutation Induced Podocyte Apoptosis by Dysregulation of NADPH Oxidase 4 and MMP-2. Kidney Int Rep 2023; 8:1864-1874. [PMID: 37705901 PMCID: PMC10496016 DOI: 10.1016/j.ekir.2023.06.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 05/15/2023] [Accepted: 06/05/2023] [Indexed: 09/15/2023] Open
Abstract
Introduction Podocyte apoptosis is a common mechanism driving progression in Alport syndrome (AS). This study aimed to investigate the mechanism of podocyte apoptosis caused by COL4A3 mutations. Methods We recruited patients with autosomal dominant AS (ADAS). Patients with minimal change disease (MCD) were recruited as controls. Microarray analysis was carried out on isolated glomeruli from the patients and validated. Then, corresponding mutant human podocytes (p.C1616Y) and 129 mice (p.C1615Y, the murine homolog to the human p.C1616Y) were constructed. The highest differentially expressed genes (DEGs) from microarray analysis were validated in transgenic mice and podocytes before and after administration of MMP-2 inhibitor (SB-3CT) and NOX4 inhibitor (GKT137831). We further validated NOX4/MMP-2/apoptosis pathway by real-time polymerase chain reaction (PCR), immunohistochemistry, and western blot in renal tissues from the ADAS patients. Results Using microarray analysis, we observed that DEGs, including NOX4/H2O2, MMP-2, and podocyte apoptosis-related genes were significantly upregulated. These genes were validated by real-time PCR, histologic analysis, and western blot in corresponding mutant human podocyte (p.C1616Y) and/or mice models (p.C1615Y). Moreover, we found podocyte apoptosis was abrogated and MMP-2 expression was down-regulated both in vivo and in vitro by NOX4 inhibition, urinary albumin-to-creatinine ratio, 24-hour proteinuria; and renal pathologic lesion was attenuated by NOX4 inhibition in vivo. Furthermore, podocyte apoptosis was attenuated whereas NOX4 expression remained the same by inhibition of MMP-2 both in vivo and in vitro. Conclusion These results indicated that NOX4 might induce podocyte apoptosis through the regulation of MMP-2 in patients with COL4A3 mutations. Our findings provided new insights into the mechanism of ADAS.
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Affiliation(s)
- Jun Tong
- Department of Nephrology, Institute of Nephrology, Shanghai Ruijin Hospital, Shanghai Jiao Tong University, School of Medicine, Shanghai, China
| | - Qimin Zheng
- Department of Nephrology, Institute of Nephrology, Shanghai Ruijin Hospital, Shanghai Jiao Tong University, School of Medicine, Shanghai, China
| | - Xiangchen Gu
- Department of Nephrology, Institute of Nephrology, Shanghai Ruijin Hospital, Shanghai Jiao Tong University, School of Medicine, Shanghai, China
| | - Qinjie Weng
- Department of Nephrology, Institute of Nephrology, Shanghai Ruijin Hospital, Shanghai Jiao Tong University, School of Medicine, Shanghai, China
| | - Shuwen Yu
- Department of Nephrology, Institute of Nephrology, Shanghai Ruijin Hospital, Shanghai Jiao Tong University, School of Medicine, Shanghai, China
| | - Zhengying Fang
- Department of Nephrology, Institute of Nephrology, Shanghai Ruijin Hospital, Shanghai Jiao Tong University, School of Medicine, Shanghai, China
| | - Hafiz Muhammad Jafar Hussain
- Department of Nephrology, Institute of Nephrology, Shanghai Ruijin Hospital, Shanghai Jiao Tong University, School of Medicine, Shanghai, China
| | - Jing Xu
- Department of Nephrology, Institute of Nephrology, Shanghai Ruijin Hospital, Shanghai Jiao Tong University, School of Medicine, Shanghai, China
| | - Hong Ren
- Department of Nephrology, Institute of Nephrology, Shanghai Ruijin Hospital, Shanghai Jiao Tong University, School of Medicine, Shanghai, China
| | - Nan Chen
- Department of Nephrology, Institute of Nephrology, Shanghai Ruijin Hospital, Shanghai Jiao Tong University, School of Medicine, Shanghai, China
| | - Jingyuan Xie
- Department of Nephrology, Institute of Nephrology, Shanghai Ruijin Hospital, Shanghai Jiao Tong University, School of Medicine, Shanghai, China
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6
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Groen In 't Woud S, Rood IM, Steenbergen E, Willemsen B, Dijkman HB, van Geel M, Schoots J, Wetzels JFM, Lugtenberg D, Deegens JKJ, Bongers EMHF. Kidney Disease Associated With Mono-allelic COL4A3 and COL4A4 Variants: A Case Series of 17 Families. Kidney Med 2023; 5:100607. [PMID: 36925663 PMCID: PMC10011433 DOI: 10.1016/j.xkme.2023.100607] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Rationale & Objective Mono-allelic variants in COL4A3 and COL4A4 (COL4A3/COL4A4) have been identified in a spectrum of glomerular basement membrane nephropathies, including thin basement membrane nephropathy and autosomal dominant Alport syndrome. With the increasing use of next generation sequencing, mono-allelic COL4A3/COL4A4 variants are detected more frequently, but phenotypic heterogeneity impedes counseling. We aimed to investigate the phenotypic spectrum, kidney biopsy results, and segregation patterns of patients with mono-allelic COL4A3/COL4A4 variants identified by whole exome sequencing. Study Design Case series. Setting & Participants We evaluated clinical and pathologic characteristics of 17 Dutch index patients with mono-allelic variants in COL4A3/COL4A4 detected by diagnostic whole exome sequencing and 25 affected family members with variants confirmed by Sanger sequencing. Results Eight different mono-allelic COL4A3/COL4A4 variants were identified across members of 11 families, comprising 7 glycine substituted missense variants and 1 frameshift variant. All index patients had microscopic hematuria at clinical presentation (median age 43 years) and 14 had (micro)albuminuria/proteinuria. All family members showed co-segregation of the variant with at least hematuria. At end of follow-up of all 42 individuals (median age 54 years), 16/42 patients had kidney function impairment, of whom 6 had kidney failure. Reports of kidney biopsies of 14 patients described thin basement membrane nephropathy, focal segmental glomerulosclerosis, minimal change lesions, and Alport syndrome. Electron microscopy images of 7 patients showed a significantly thinner glomerular basement membrane compared with images of patients with idiopathic focal segmental glomerulosclerosis and other hereditary glomerular diseases. No genotype-phenotype correlations could be established. Limitations Retrospective design, ascertainment bias toward severe kidney phenotypes, and familial hematuria. Conclusions This study confirms the wide phenotypic spectrum associated with mono-allelic COL4A3/COL4A4 variants, extending from isolated microscopic hematuria to kidney failure with high intra- and interfamilial variability.
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Affiliation(s)
- Sander Groen In 't Woud
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands.,Department for Health Evidence, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Ilse M Rood
- Department of Nephrology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Eric Steenbergen
- Department of Pathology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Brigith Willemsen
- Department of Pathology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Henry B Dijkman
- Department of Pathology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Michel van Geel
- Department of Clinical Genetics, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Jeroen Schoots
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jack F M Wetzels
- Department of Nephrology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Dorien Lugtenberg
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jeroen K J Deegens
- Department of Nephrology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Ernie M H F Bongers
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
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Gregorio VD, Caparali B, Shojaei A, Ricardo S, Barua M. Alport Syndrome: Clinical Spectrum and Therapeutic Advances. Kidney Med 2023; 5:100631. [PMID: 37122389 PMCID: PMC10131117 DOI: 10.1016/j.xkme.2023.100631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/08/2023] Open
Abstract
Alport syndrome is a hereditary disorder characterized by kidney disease, ocular abnormalities, and sensorineural hearing loss. Work in understanding the cause of Alport syndrome and the molecular composition of the glomerular basement membrane ultimately led to the identification of COL4A3, COL4A4 (both on chromosome 2q36), and COL4A5 (chromosome Xq22), encoding the α3, α4, and α5 chains of type IV collagen, as the responsible genes. Subsequent studies suggested that autosomal recessive Alport syndrome and males with X-linked Alport syndrome have more severe disease, whereas autosomal dominant Alport syndrome and females with X-linked Alport syndrome have more variability. Variant type is also influential-protein-truncating variants in autosomal recessive Alport syndrome or males with X-linked Alport syndrome often present with severe symptoms, characterized by kidney failure, extrarenal manifestations, and lack of the α3-α4-α5(IV) network. By contrast, mild-moderate forms from missense variants display α3-α4-α5(IV) in the glomerular basement membrane and are associated with protracted kidney involvement without extrarenal manifestations. Regardless of type, therapeutic intervention for kidney involvement is focused on early initiation of angiotensin-converting enzyme inhibitors. There are several therapies under investigation including sodium/glucose cotransporter 2 inhibitors, aminoglycoside analogs, endothelin type A antagonists, lipid-modifying drugs, and hydroxychloroquine, although targeting the underlying defect through gene therapy remains in preclinical stages.
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8
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Thomas CP, Daloul R, Lentine KL, Gohh R, Anand PM, Rasouly HM, Sharfuddin AA, Schlondorff JS, Rodig NM, Freese ME, Garg N, Lee BK, Caliskan Y. Genetic evaluation of living kidney donor candidates: a review and recommendations for best practices. Am J Transplant 2023; 23:597-607. [PMID: 36868514 DOI: 10.1016/j.ajt.2023.02.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 01/25/2023] [Accepted: 02/20/2023] [Indexed: 03/05/2023]
Abstract
The growing accessibility and falling costs of genetic sequencing techniques has expanded the utilization of genetic testing in clinical practice. For living kidney donation, genetic evaluation has been increasingly used to identify genetic kidney disease in potential candidates, especially in those of younger ages. However, genetic testing on asymptomatic living kidney donors remains fraught with many challenges and uncertainties. Not all transplant practitioners are aware of the limitations of genetic testing, are comfortable with selecting testing methods, comprehending test results, or providing counsel, and many do not have access to a renal genetic counselor or a clinical geneticist. Although genetic testing can be a valuable tool in living kidney donor evaluation, its overall benefit in donor evaluation has not been demonstrated and it can also lead to confusion, inappropriate donor exclusion, or misleading reassurance. Until more published data become available, this practice resource should provide guidance for centers and transplant practitioners on the responsible use of genetic testing in the evaluation of living kidney donor candidates.
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Affiliation(s)
- Christie P Thomas
- Department of of Internal Medicine and Iowa Institute of Human Genetics, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA; VA Medical Center, Iowa City, Iowa, USA.
| | - Reem Daloul
- Division of Nephrology, Department of Internal Medicine, Allegheny General Hospital, Pittsburgh, Pennsylvania, USA
| | - Krista L Lentine
- Saint Louis University Transplant Center, SSM Health Saint Louis University Hospital, St. Louis, Missouri, USA
| | - Reginald Gohh
- Department of Medicine, Warren Alpert Medical School of Brown University, Providence, Rhode Island, USA
| | - Prince M Anand
- Mid-Carolinas Transplant Center, Medical University of South Carolina, Lancaster, South Carolina, USA
| | - Hila Milo Rasouly
- Center for Precision Medicine and Genomics, Department of Medicine, Columbia University, New York City, New York, USA
| | - Asif A Sharfuddin
- Division of Nephrology and Transplant, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Johannes S Schlondorff
- Department of Internal Medicine, Ohio State University Medical Center, Columbus, Ohio, USA
| | - Nancy M Rodig
- Department of Pediatrics, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Margaret E Freese
- Department of of Internal Medicine and Iowa Institute of Human Genetics, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Neetika Garg
- Division of Nephrology, Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Brian K Lee
- Kidney/Pancreas Transplant Center, Dell Seton Medical Center, University of Texas at Austin, Austin, Texas, USA
| | - Yasar Caliskan
- Saint Louis University Transplant Center, SSM Health Saint Louis University Hospital, St. Louis, Missouri, USA
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9
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Wildin RS, Gerrard DL, Leonard DGB. Real-World Results from Combined Screening for Monogenic Genomic Health Risks and Reproductive Risks in 300 Adults. J Pers Med 2022; 12:jpm12121962. [PMID: 36556183 PMCID: PMC9782229 DOI: 10.3390/jpm12121962] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 10/28/2022] [Accepted: 11/15/2022] [Indexed: 11/29/2022] Open
Abstract
New methods and demonstrations of feasibility guide future implementation of genomic population health screening programs. This is the first report of genomic population screening in a primary care, non-research setting using existing large carrier and health risk gene sequencing panels combined into one 432-gene test that is offered to adults of any health status. This report summarizes basic demographic data and analyses patterns of pathogenic and likely pathogenic genetic findings for the first 300 individuals tested in this real-world scenario. We devised a classification system for gene results to facilitate clear message development for our Genomic Medicine Action Plan messaging tool used to summarize and activate results for patients and primary care providers. Potential genetic health risks of various magnitudes for a broad range of disorders were identified in 16% to 34% of tested individuals. The frequency depends on criteria used for the type and penetrance of risk. 86% of individuals are carriers for one or more recessive diseases. Detecting, reporting, and guiding response to diverse genetic health risks and recessive carrier states in a single primary care genomic screening test appears feasible and effective. This is an important step toward exploring an exome or genome sequence as a multi-purpose clinical screening tool.
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Affiliation(s)
- Robert S. Wildin
- Laboratory Medicine and Pediatrics & Departments of Pathology, Robert Larner M.D. College of Medicine at the University of Vermont, University of Vermont Health Network, Burlington, VT 05401, USA
- Correspondence:
| | - Diana L. Gerrard
- Laboratory Medicine & Department of Pathology, University of Vermont Medical Center, Burlington, VT 05401, USA
| | - Debra G. B. Leonard
- Laboratory Medicine & Department of Pathology, Robert Larner M.D. College of Medicine at the University of Vermont, University of Vermont Health Network, Burlington, VT 05401, USA
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10
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García-Aznar JM, De la Higuera L, Besada Cerecedo L, Gandiaga NP, Vega AI, Fernández-Fresnedo G, González-Lamuño D. New Insights into Renal Failure in a Cohort of 317 Patients with Autosomal Dominant Forms of Alport Syndrome: Report of Two Novel Heterozygous Mutations in COL4A3. J Clin Med 2022; 11:jcm11164883. [PMID: 36013122 PMCID: PMC9409901 DOI: 10.3390/jcm11164883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 07/27/2022] [Accepted: 08/12/2022] [Indexed: 11/24/2022] Open
Abstract
Alport syndrome (AS) is a clinically and genetically heterogeneous disorder with a wide phenotypic spectrum, onset, and progression. X-linked AS (XLAS) and autosomal recessive AS (ARAS) are severe conditions, whereas the severity of autosomal dominant AS (ADAS) may vary from benign familial hematuria to progressive renal disease with extra-renal manifestations. In this study, we collated information from the literature and analyzed a cohort of 317 patients with ADAS carrying heterozygous disease-causing mutations in COL4A3/4 including four patients from two unrelated families who carried two novel variants in COL4A3. Regarding the age of onset of the disease, 80% of patients presented urinalysis alterations (microhematuria, hematuria, and/or proteinuria) before the age of 40 years. The cumulative probability of suffering adverse renal events was mainly observed between 30 and 70 years, without statistical differences between COL4A3 and COL4A4. We observed statistically significant differences between the sexes in the age of developing ESKD in cases affected by mutations in COL4A3/4 (p value = 0.0097), suggesting that males begin experiencing earlier deterioration of renal function than women. This study supports the importance of follow-up in young patients who harbor pathogenic mutations in COL4A3/4. We update the knowledge of ADAS, highlighting differences in the progression of the disease between males and females.
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Affiliation(s)
| | | | | | - Nerea Paz Gandiaga
- Servicio de Genética, Hospital Universitario Marqués de Valdecilla, 39008 Santander, Spain
| | - Ana Isabel Vega
- Servicio de Genética, Hospital Universitario Marqués de Valdecilla, 39008 Santander, Spain
| | - Gema Fernández-Fresnedo
- Servicio de Nefrología, Hospital Universitario Marqués de Valdecilla, 39008 Santander, Spain
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11
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Agrawal N, Meena S, Shiromani S, Singh KJ. Hypertensive retinopathy in a young patient! Don't forget Alport syndrome. Indian J Ophthalmol 2022; 70:2701-2702. [PMID: 35791212 PMCID: PMC9426194 DOI: 10.4103/ijo.ijo_117_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Nikhil Agrawal
- Department of Ophthalmology, AIIMS Jodhpur, Basni Road, Jodhpur, Rajasthan, India
| | - Seema Meena
- Department of Ophthalmology, AIIMS Jodhpur, Basni Road, Jodhpur, Rajasthan, India
| | - Sakshi Shiromani
- Department of Ophthalmology, AIIMS Jodhpur, Basni Road, Jodhpur, Rajasthan, India
| | - Kirti Jai Singh
- Department of Ophthalmology, AIIMS Jodhpur, Basni Road, Jodhpur, Rajasthan, India
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12
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Genetic Kidney Diseases (GKDs) Modeling Using Genome Editing Technologies. Cells 2022; 11:cells11091571. [PMID: 35563876 PMCID: PMC9105797 DOI: 10.3390/cells11091571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 04/29/2022] [Accepted: 05/04/2022] [Indexed: 02/05/2023] Open
Abstract
Genetic kidney diseases (GKDs) are a group of rare diseases, affecting approximately about 60 to 80 per 100,000 individuals, for which there is currently no treatment that can cure them (in many cases). GKDs usually leads to early-onset chronic kidney disease, which results in patients having to undergo dialysis or kidney transplant. Here, we briefly describe genetic causes and phenotypic effects of six GKDs representative of different ranges of prevalence and renal involvement (ciliopathy, glomerulopathy, and tubulopathy). One of the shared characteristics of GKDs is that most of them are monogenic. This characteristic makes it possible to use site-specific nuclease systems to edit the genes that cause GKDs and generate in vitro and in vivo models that reflect the genetic abnormalities of GKDs. We describe and compare these site-specific nuclease systems (zinc finger nucleases (ZFNs), transcription activator-like effect nucleases (TALENs) and regularly clustered short palindromic repeat-associated protein (CRISPR-Cas9)) and review how these systems have allowed the generation of cellular and animal GKDs models and how they have contributed to shed light on many still unknown fields in GKDs. We also indicate the main obstacles limiting the application of these systems in a more efficient way. The information provided here will be useful to gain an accurate understanding of the technological advances in the field of genome editing for GKDs, as well as to serve as a guide for the selection of both the genome editing tool and the gene delivery method most suitable for the successful development of GKDs models.
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13
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Mukherjee K, Gu C, Collins A, Mettlen M, Samelko B, Altintas MM, Sudhini YR, Wang X, Bouley R, Brown D, Pedro BP, Bane SL, Gupta V, Brinkkoetter PT, Hagmann H, Reiser J, Sever S. Simultaneous stabilization of actin cytoskeleton in multiple nephron-specific cells protects the kidney from diverse injury. Nat Commun 2022; 13:2422. [PMID: 35504916 PMCID: PMC9065033 DOI: 10.1038/s41467-022-30101-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Accepted: 04/04/2022] [Indexed: 02/07/2023] Open
Abstract
Chronic kidney diseases and acute kidney injury are mechanistically distinct kidney diseases. While chronic kidney diseases are associated with podocyte injury, acute kidney injury affects renal tubular epithelial cells. Despite these differences, a cardinal feature of both acute and chronic kidney diseases is dysregulated actin cytoskeleton. We have shown that pharmacological activation of GTPase dynamin ameliorates podocyte injury in murine models of chronic kidney diseases by promoting actin polymerization. Here we establish dynamin's role in modulating stiffness and polarity of renal tubular epithelial cells by crosslinking actin filaments into branched networks. Activation of dynamin's crosslinking capability by a small molecule agonist stabilizes the actomyosin cortex of the apical membrane against injury, which in turn preserves renal function in various murine models of acute kidney injury. Notably, a dynamin agonist simultaneously attenuates podocyte and tubular injury in the genetic murine model of Alport syndrome. Our study provides evidence for the feasibility and highlights the benefits of novel holistic nephron-protective therapies.
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Affiliation(s)
- Kamalika Mukherjee
- Department of Medicine, Harvard Medical School and Division of Nephrology, Massachusetts General Hospital, Boston, MA, USA
| | - Changkyu Gu
- Department of Medicine, Harvard Medical School and Division of Nephrology, Massachusetts General Hospital, Boston, MA, USA
| | - Agnieszka Collins
- Department of Medicine, Harvard Medical School and Division of Nephrology, Massachusetts General Hospital, Boston, MA, USA
| | - Marcel Mettlen
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Beata Samelko
- Department of Medicine, Rush University Medical Center, Chicago, IL, USA
| | - Mehmet M Altintas
- Department of Medicine, Rush University Medical Center, Chicago, IL, USA
| | | | - Xuexiang Wang
- Department of Medicine, Rush University Medical Center, Chicago, IL, USA
| | - Richard Bouley
- Department of Medicine, Harvard Medical School and Division of Nephrology, Massachusetts General Hospital, Boston, MA, USA
| | - Dennis Brown
- Department of Medicine, Harvard Medical School and Division of Nephrology, Massachusetts General Hospital, Boston, MA, USA
| | - Bradley P Pedro
- Department of Medicine, Harvard Medical School and Division of Nephrology, Massachusetts General Hospital, Boston, MA, USA
| | - Susan L Bane
- Department of Chemistry, Binghamton University, State University of New York, Binghamton, NY, USA
| | - Vineet Gupta
- Department of Medicine, Rush University Medical Center, Chicago, IL, USA
| | - Paul T Brinkkoetter
- Department of Internal Medicine-Center for Molecular Medicine Cologne, University of Cologne and Faculty of Medicine-University Hospital Cologne, Cologne, Germany
- Cologne Cluster of Excellence on Cellular Stress Responses in Ageing-Associated Diseases (CECAD) and Systems Biology of Ageing Cologne (Sybacol), Cologne, Germany
| | - Henning Hagmann
- Department of Internal Medicine-Center for Molecular Medicine Cologne, University of Cologne and Faculty of Medicine-University Hospital Cologne, Cologne, Germany
- Cologne Cluster of Excellence on Cellular Stress Responses in Ageing-Associated Diseases (CECAD) and Systems Biology of Ageing Cologne (Sybacol), Cologne, Germany
| | - Jochen Reiser
- Department of Medicine, Rush University Medical Center, Chicago, IL, USA.
| | - Sanja Sever
- Department of Medicine, Harvard Medical School and Division of Nephrology, Massachusetts General Hospital, Boston, MA, USA.
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14
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Barua M, Paterson AD. Population-based studies reveal an additive role of type IV collagen variants in hematuria and albuminuria. Pediatr Nephrol 2022; 37:253-262. [PMID: 33635378 DOI: 10.1007/s00467-021-04934-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 10/31/2020] [Accepted: 01/07/2021] [Indexed: 02/08/2023]
Abstract
Specific variants in genes that encode the α3α4α5 chains of type IV collagen cause Alport syndrome (AS), which encompass a clinical spectrum from isolated hematuria to multisystem disease affecting sight, hearing and kidney function. The commonest form is X-linked Alport syndrome (XLAS; COL4A5) with autosomal AS (COL4A3 and COL4A4) comprising a minority of cases. While historic data estimates the frequency of AS at 1:5000-10,000, recent population-based genetic studies suggest the prevalence is considerably higher. Genome-wide association studies (GWAS) have been performed in the Icelandic (deCODE) and UK (UK Biobank) populations, demonstrating an association of type IV collagen gene variants with AS relevant kidney traits. In the Icelandic population, 1 in 600 carries a 2.5-kb COL4A3 coding deletion or a COL4A3 missense variant (rs200287952[A], Gly695Arg), both of which are strongly associated with hematuria and albuminuria (P values = 1.9 × 10-5 to 2.5 × 10-20). In the UK Biobank, COL4A4 rs35138315 (Ser969X; carrier frequency 0.13%) is strongly associated with both hematuria and albuminuria (P = 1.5 × 10-73). Thus, the frequency for autosomal AS is 5-16 times higher than the historic prevalence of all forms of the disorder. Furthermore, COL4A4 rs3518315 (Ser969X) is also a reported founder mutation in families with autosomal dominant focal and segmental glomerulosclerosis and autosomal recessive forms of AS. This supports an additive mode of inheritance for specific variants, wherein a number of copies of a mutation influence disease severity in a cumulative fashion. These studies did not include the X chromosome, excluding analysis of COL4A5, which represents an area for future study.
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Affiliation(s)
- Moumita Barua
- Division of Nephrology, Toronto General Hospital, 200 Elizabeth Street, 8NU-855, Toronto, ON, M5G 2C4, Canada. .,Department of Medicine, University of Toronto, Toronto, Canada. .,Toronto General Hospital Research Institute, University Health Network, Toronto, Canada. .,Institute of Medical Sciences, University of Toronto, Toronto, Canada.
| | - Andrew D Paterson
- Institute of Medical Sciences, University of Toronto, Toronto, Canada.,Divisions of Epidemiology and Biostatistics, Dalla Lana School of Public Health, Toronto, Canada.,Genetics and Genome Biology, Research Institute at Hospital for Sick Children, Toronto, Canada
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15
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Martínez-Pulleiro R, García-Murias M, Fidalgo-Díaz M, García-González MÁ. Molecular Basis, Diagnostic Challenges and Therapeutic Approaches of Alport Syndrome: A Primer for Clinicians. Int J Mol Sci 2021; 22:ijms222011063. [PMID: 34681722 PMCID: PMC8541626 DOI: 10.3390/ijms222011063] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 10/06/2021] [Accepted: 10/11/2021] [Indexed: 12/20/2022] Open
Abstract
Alport syndrome is a genetic and hereditary disease, caused by mutations in the type IV collagen genes COL4A3, COL4A4 and COL4A5, that affects the glomerular basement membrane of the kidney. It is a rare disease with an underestimated prevalence. Genetic analysis of population cohorts has revealed that it is the second most common inherited kidney disease after polycystic kidney disease. Renal involvement is the main manifestation, although it may have associated extrarenal manifestations such as hearing loss or ocular problems. The degree of expression of the disease changes according to the gene affected and other factors, known or yet to be known. The pathophysiology is not yet fully understood, although some receptors, pathways or molecules are known to be linked to the disease. There is also no specific treatment for Alport syndrome; the most commonly used are renin–angiotensin–aldosterone system inhibitors. In recent years, diagnosis has come a long way, thanks to advances in DNA sequencing technologies such as next-generation sequencing (NGS). Further research at the genetic and molecular levels in the future will complete the partial vision of the pathophysiological mechanism that we have, and will allow us to better understand what is happening and how to solve it.
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Affiliation(s)
- Raquel Martínez-Pulleiro
- Grupo de Xenética e Bioloxía do Desenvolvemento das Enfermidades Renais, Laboratorio de Nefroloxía (No. 11), Instituto de Investigación Sanitaria de Santiago (IDIS), Complexo Hospitalario de Santiago de Compostela (CHUS), 15706 Santiago de Compostela, Spain; (R.M.-P.); (M.G.-M.)
- Grupo de Medicina Xenómica (GMX), 15706 Santiago de Compostela, Spain
| | - María García-Murias
- Grupo de Xenética e Bioloxía do Desenvolvemento das Enfermidades Renais, Laboratorio de Nefroloxía (No. 11), Instituto de Investigación Sanitaria de Santiago (IDIS), Complexo Hospitalario de Santiago de Compostela (CHUS), 15706 Santiago de Compostela, Spain; (R.M.-P.); (M.G.-M.)
- Grupo de Medicina Xenómica (GMX), 15706 Santiago de Compostela, Spain
| | - Manuel Fidalgo-Díaz
- Departamento de Nefrología, Complexo Hospitalario Universitario de Santiago (CHUS), 15706 Santiago de Compostela, Spain;
| | - Miguel Ángel García-González
- Grupo de Xenética e Bioloxía do Desenvolvemento das Enfermidades Renais, Laboratorio de Nefroloxía (No. 11), Instituto de Investigación Sanitaria de Santiago (IDIS), Complexo Hospitalario de Santiago de Compostela (CHUS), 15706 Santiago de Compostela, Spain; (R.M.-P.); (M.G.-M.)
- Grupo de Medicina Xenómica (GMX), 15706 Santiago de Compostela, Spain
- Fundación Pública Galega de Medicina Xenómica-SERGAS, Complexo Hospitalario de Santiago de Compostela (CHUS), 15706 Santiago de Compostela, Spain
- Correspondence: ; Tel.: +34-981-555-197
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16
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Rossanti R, Horinouchi T, Yamamura T, Nagano C, Sakakibara N, Ishiko S, Aoto Y, Kondo A, Nagai S, Okada E, Ishimori S, Nagase H, Matsui S, Tamagaki K, Ubara Y, Nagahama M, Shima Y, Nakanishi K, Ninchoji T, Matsuo M, Iijima K, Nozu K. Evaluation of Suspected Autosomal Alport Syndrome Synonymous Variants. KIDNEY360 2021; 3:497-505. [PMID: 35582193 PMCID: PMC9034806 DOI: 10.34067/kid.0005252021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 10/11/2021] [Indexed: 01/10/2023]
Abstract
Background Alport syndrome is an inherited disorder characterized by progressive renal disease, variable sensorineural hearing loss, and ocular abnormalities. Although many pathogenic variants in COL4A3 and COL4A4 have been identified in patients with autosomal Alport syndrome, synonymous mutations in these genes have rarely been identified. Methods We conducted in silico splicing analysis using Human Splicing Finder (HSF) and Alamut to predict splicing domain strength and disruption of the sites. Furthermore, we performed in vitro splicing assays using minigene constructs and mRNA analysis of patient samples to determine the pathogenicity of four synonymous variants detected in four patients with suspected autosomal dominant Alport syndrome (COL4A3 [c.693G>A (p.Val231=)] and COL4A4 [c.1353C>T (p.Gly451=), c.735G>A (p.Pro245=), and c.870G>A (p.Lys290=)]). Results Both in vivo and in vitro splicing assays showed exon skipping in two out of the four synonymous variants identified (c.735G>A and c.870G>A in COL4A4). Prediction analysis of wild-type and mutated COL4A4 sequences using HSF and Alamut suggested these two variants may lead to the loss of binding sites for several splicing factors, e.g., in acceptor sites and exonic splicing enhancers. The other two variants did not induce aberrant splicing. Conclusions This study highlights the pitfalls of classifying the functional consequences of variants by a simple approach. Certain synonymous variants, although they do not alter the amino acid sequence of the encoded protein, can dramatically affect pre-mRNA splicing, as shown in two of our patients. Our findings indicate that transcript analysis should be carried out to evaluate synonymous variants detected in patients with autosomal dominant Alport syndrome.
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Affiliation(s)
- Rini Rossanti
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan,Department of Child Health, Nephrology Division, Dr. Hasan Sadikin General Hospital/Faculty of Medicine, Universitas Padjadjaran, Bandung, Indonesia
| | - Tomoko Horinouchi
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Tomohiko Yamamura
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - China Nagano
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Nana Sakakibara
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Shinya Ishiko
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Yuya Aoto
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Atsushi Kondo
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Sadayuki Nagai
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Eri Okada
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Shingo Ishimori
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Hiroaki Nagase
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Satoshi Matsui
- Department of Nephrology and Hypertension, Mitsubishi Kyoto Hospital, Kyoto, Japan
| | - Keiichi Tamagaki
- Department of Nephrology, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Yoshifumi Ubara
- Nephrology Center, Okinaka Memorial Institute for Medical Research, Tokyo, Japan
| | | | - Yuko Shima
- Department of Pediatrics, Wakayama Medical University, Wakayama, Japan
| | - Koichi Nakanishi
- Department of Child Health and Welfare (Pediatrics), Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan
| | - Takeshi Ninchoji
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Masafumi Matsuo
- Research Center for Locomotion Biology, Kobe Gakuin University, Kobe, Japan
| | - Kazumoto Iijima
- Hyogo Prefectural Kobe Children’s Hospital, Kobe, Japan,Department of Advanced Pediatric Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Kandai Nozu
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
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17
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Furlano M, Martínez V, Pybus M, Arce Y, Crespí J, Venegas MDP, Bullich G, Domingo A, Ayasreh N, Benito S, Lorente L, Ruíz P, Gonzalez VL, Arlandis R, Cabello E, Torres F, Guirado L, Ars E, Torra R. Clinical and Genetic Features of Autosomal Dominant Alport Syndrome: A Cohort Study. Am J Kidney Dis 2021; 78:560-570.e1. [PMID: 33838161 DOI: 10.1053/j.ajkd.2021.02.326] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Accepted: 02/14/2021] [Indexed: 12/15/2022]
Abstract
RATIONALE & OBJECTIVE Alport syndrome is a common genetic kidney disease accounting for approximately 2% of patients receiving kidney replacement therapy (KRT). It is caused by pathogenic variants in the gene COL4A3, COL4A4, or COL4A5. The aim of this study was to evaluate the clinical and genetic spectrum of patients with autosomal dominant Alport syndrome (ADAS). STUDY DESIGN Retrospective cohort study. SETTING & PARTICIPANTS 82 families (252 patients) with ADAS were studied. Clinical, genetic, laboratory, and pathology data were collected. OBSERVATIONS A pathogenic DNA variant in COL4A3 was identified in 107 patients (35 families), whereas 133 harbored a pathogenic variant in COL4A4 (43 families). Digenic/complex inheritance was observed in 12 patients. Overall, the median kidney survival was 67 (95% CI, 58-73) years, without significant differences across sex (P=0.8), causative genes (P=0.6), or type of variant (P=0.9). Microhematuria was the most common kidney manifestation (92.1%), and extrarenal features were rare. Findings on kidney biopsies ranged from normal to focal segmental glomerulosclerosis. The slope of estimated glomerular filtration rate change was-1.46 (-1.66 to-1.26) mL/min/1.73m2 per year for the overall group, with no significant differences between ADAS genes (P=0.2). LIMITATIONS The relatively small size of this series from a single country, potentially limiting generalizability. CONCLUSIONS Patients with ADAS have a wide spectrum of clinical presentations, ranging from asymptomatic to kidney failure, a pattern not clearly related to the causative gene or type of variant. The diversity of ADAS phenotypes contributes to its underdiagnosis in clinical practice.
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Affiliation(s)
- Mónica Furlano
- Inherited Kidney Diseases, Nephrology Department, Fundació Puigvert, Instituto de Investigaciones Biomédicas Sant Pau, Medicine Department-Universitat Autónoma de Barcelona, Red de Investigación Renal, Instituto de Investigación Carlos III, Barcelona, Spain
| | - Victor Martínez
- Nephrology Department, Hospital Clínico Universitario Virgen de la Arrixaca, Murcia, Spain
| | - Marc Pybus
- Molecular Biology Laboratory, Fundació Puigvert, Instituto de Investigaciones Biomédicas Sant Pau, Universitat Autónoma de Barcelona, Red de Investigación Renal, Instituto de Investigación Carlos III, Barcelona, Spain
| | - Yolanda Arce
- Department of Pathology, Fundació Puigvert, Instituto de Investigaciones Biomédicas Sant Pau, Universitat Autónoma de Barcelona, Red de Investigación Renal, Instituto de Investigación Carlos III, Barcelona, Spain
| | - Jaume Crespí
- Departments of Ophthalmology, Hospital de Sant Pau i la Santa Creu, Instituto de Investigaciones Biomédicas Sant Pau, Universitat Autónoma de Barcelona, Barcelona, Spain
| | - María Del Prado Venegas
- Otolaryngology-Head and Neck Surgery, Hospital de Sant Pau i la Santa Creu, Instituto de Investigaciones Biomédicas Sant Pau, Universitat Autónoma de Barcelona, Barcelona, Spain
| | - Gemma Bullich
- Centre Nacional d'Anàlisi Genómica, Centre for Genomic Regulation, Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Andrea Domingo
- Molecular Biology Laboratory, Fundació Puigvert, Instituto de Investigaciones Biomédicas Sant Pau, Universitat Autónoma de Barcelona, Red de Investigación Renal, Instituto de Investigación Carlos III, Barcelona, Spain
| | - Nadia Ayasreh
- Nephrology Department, Fundació Puigvert, Instituto de Investigaciones Biomédicas Sant Pau, Medicine Department-Universitat Autónoma de Barcelona, Red de Investigación Renal, Instituto de Investigación Carlos III, Barcelona, Spain
| | - Silvia Benito
- Nephrology Department, Fundació Puigvert, Instituto de Investigaciones Biomédicas Sant Pau, Medicine Department-Universitat Autónoma de Barcelona, Red de Investigación Renal, Instituto de Investigación Carlos III, Barcelona, Spain
| | - Laura Lorente
- Molecular Biology Laboratory, Fundació Puigvert, Instituto de Investigaciones Biomédicas Sant Pau, Universitat Autónoma de Barcelona, Red de Investigación Renal, Instituto de Investigación Carlos III, Barcelona, Spain
| | - Patricia Ruíz
- Molecular Biology Laboratory, Fundació Puigvert, Instituto de Investigaciones Biomédicas Sant Pau, Universitat Autónoma de Barcelona, Red de Investigación Renal, Instituto de Investigación Carlos III, Barcelona, Spain
| | - Vanesa López Gonzalez
- Genetics Laboratory, Hospital Clínico Universitario Virgen de la Arrixaca, Murcia, Spain
| | - Rosa Arlandis
- Nephrology Department, Hospital General de la Palma, Islas Canarias, Spain
| | - Elisa Cabello
- Nephrology Department, Hospital General Universitario de Castellón, Castellón de la Plana, Spain
| | - Ferran Torres
- Biostatistics Unit, Faculty of Medicine, Universitat Autònoma de Barcelona, Barcelona, Spain; Medical Statistics Core Facility, Institut d'Investigacions Biomèdiques August Pi i Sunyer, Hospital Clinic de Barcelona, Barcelona, Spain
| | - Lluis Guirado
- Nephrology Department, Fundació Puigvert, Instituto de Investigaciones Biomédicas Sant Pau, Medicine Department-Universitat Autónoma de Barcelona, Red de Investigación Renal, Instituto de Investigación Carlos III, Barcelona, Spain
| | - Elisabet Ars
- Molecular Biology Laboratory, Fundació Puigvert, Instituto de Investigaciones Biomédicas Sant Pau, Universitat Autónoma de Barcelona, Red de Investigación Renal, Instituto de Investigación Carlos III, Barcelona, Spain.
| | - Roser Torra
- Inherited Kidney Diseases, Nephrology Department, Fundació Puigvert, Instituto de Investigaciones Biomédicas Sant Pau, Medicine Department-Universitat Autónoma de Barcelona, Red de Investigación Renal, Instituto de Investigación Carlos III, Barcelona, Spain.
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18
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Sabir AH, Singh A, Elley G, Wassemer E, Foster K, Sloman M, Lim D. A second report of recessive type COL4A1-related disorder: a novel homozygous missense variant. Clin Dysmorphol 2021; 30:115-119. [PMID: 33491999 DOI: 10.1097/mcd.0000000000000362] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- Ataf H Sabir
- Department of Clinical Genetics, Birmingham Women's and Children's NHS Foundation Trust & Birmingham Health Partners
- Department of Medicine, University of Birmingham, Birmingham
| | - Ananya Singh
- Department of Medicine, University of Birmingham, Birmingham
| | - George Elley
- Foundation of Doctor, Department of Medicine, Ashford and St Peter's NHS Trust, Ashford
| | | | - Katharine Foster
- Department of Paediatric Radiology, Birmingham Women's and Children's Hospital NHS Trust & Birmingham Health Partners, Birmingham
| | - Melissa Sloman
- Exeter Genomics Laboratory, Royal Devon & Exeter NHS Foundation Trust, Exeter, UK
| | - Derek Lim
- Department of Clinical Genetics, Birmingham Women's and Children's NHS Foundation Trust & Birmingham Health Partners
- Department of Medicine, University of Birmingham, Birmingham
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19
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Shulman C, Liang E, Kamura M, Udwan K, Yao T, Cattran D, Reich H, Hladunewich M, Pei Y, Savige J, Paterson AD, Suico MA, Kai H, Barua M. Type IV Collagen Variants in CKD: Performance of Computational Predictions for Identifying Pathogenic Variants. Kidney Med 2021; 3:257-266. [PMID: 33851121 PMCID: PMC8039416 DOI: 10.1016/j.xkme.2020.12.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Rationale & Objective Pathogenic variants in type IV collagen have been reported to account for a significant proportion of chronic kidney disease. Accordingly, genetic testing is increasingly used to diagnose kidney diseases, but testing also may reveal rare missense variants that are of uncertain clinical significance. To aid in interpretation, computational prediction (called in silico) programs may be used to predict whether a variant is clinically important. We evaluate the performance of in silico programs for COL4A3/A4/A5 variants. Study Design, Setting, & Participants Rare missense variants in COL4A3/A4/A5 were identified in disease cohorts, including a local focal segmental glomerulosclerosis (FSGS) cohort and publicly available disease databases, in which they are categorized as pathogenic or benign based on clinical criteria. Tests Compared & Outcomes All rare missense variants identified in the 4 disease cohorts were subjected to in silico predictions using 12 different programs. Comparisons between the predictions were compared with: (1) variant classification (pathogenic or benign) in the cohorts and (2) functional characterization in a randomly selected smaller number (17) of pathogenic or uncertain significance variants obtained from the local FSGS cohort. Results In silico predictions correctly classified 75% to 97% of pathogenic and 57% to 100% of benign COL4A3/A4/A5 variants in public disease databases. The congruency of in silico predictions was similar for variants categorized as pathogenic and benign, with the exception of benign COL4A5 variants, in which disease effects were overestimated. By contrast, in silico predictions and functional characterization classified all 9 pathogenic COL4A3/A4/A5 variants correctly that were obtained from a local FSGS cohort. However, these programs also overestimated the effects of genomic variants of uncertain significance when compared with functional characterization. Each of the 12 in silico programs used yielded similar results. Limitations Overestimation of in silico program sensitivity given that they may have been used in the categorization of variants labeled as pathogenic in disease repositories. Conclusions Our results suggest that in silico predictions are sensitive but not specific to assign COL4A3/A4/A5 variant pathogenicity, with misclassification of benign variants and variants of uncertain significance. Thus, we do not recommend in silico programs but instead recommend pursuing more objective levels of evidence suggested by medical genetics guidelines.
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Affiliation(s)
- Cole Shulman
- Division of Nephrology, University Health Network, Toronto, Canada.,Toronto General Hospital Research Institute, Toronto General Hospital, Toronto, Canada
| | - Emerald Liang
- Division of Nephrology, University Health Network, Toronto, Canada.,Toronto General Hospital Research Institute, Toronto General Hospital, Toronto, Canada
| | - Misato Kamura
- Department of Molecular Medicine, Graduate School of Pharmaceutical Science, Kumamoto University, Kumamoto, Japan
| | - Khalil Udwan
- Division of Nephrology, University Health Network, Toronto, Canada.,Toronto General Hospital Research Institute, Toronto General Hospital, Toronto, Canada
| | - Tony Yao
- Division of Nephrology, University Health Network, Toronto, Canada.,Toronto General Hospital Research Institute, Toronto General Hospital, Toronto, Canada
| | - Daniel Cattran
- Division of Nephrology, University Health Network, Toronto, Canada.,Toronto General Hospital Research Institute, Toronto General Hospital, Toronto, Canada.,Institute of Medical Sciences, Toronto, Canada.,Department of Medicine, Toronto, Canada
| | - Heather Reich
- Division of Nephrology, University Health Network, Toronto, Canada.,Toronto General Hospital Research Institute, Toronto General Hospital, Toronto, Canada.,Institute of Medical Sciences, Toronto, Canada.,Department of Medicine, Toronto, Canada
| | - Michelle Hladunewich
- Division of Nephrology, University Health Network, Toronto, Canada.,Toronto General Hospital Research Institute, Toronto General Hospital, Toronto, Canada.,Institute of Medical Sciences, Toronto, Canada.,Department of Medicine, Toronto, Canada
| | - York Pei
- Division of Nephrology, University Health Network, Toronto, Canada.,Toronto General Hospital Research Institute, Toronto General Hospital, Toronto, Canada.,Institute of Medical Sciences, Toronto, Canada.,Department of Medicine, Toronto, Canada
| | - Judy Savige
- University of Melbourne, Melbourne, Australia
| | - Andrew D Paterson
- Division of Epidemiology and Biostatistics, Dalla Lana School of Public Health, Toronto, Canada.,Genetics and Genome Biology, Research Institute at Hospital for Sick Children, Toronto, Canada
| | - Mary Ann Suico
- Department of Molecular Medicine, Graduate School of Pharmaceutical Science, Kumamoto University, Kumamoto, Japan
| | - Hirofumi Kai
- Department of Molecular Medicine, Graduate School of Pharmaceutical Science, Kumamoto University, Kumamoto, Japan
| | - Moumita Barua
- Division of Nephrology, University Health Network, Toronto, Canada.,Toronto General Hospital Research Institute, Toronto General Hospital, Toronto, Canada.,Institute of Medical Sciences, Toronto, Canada.,Department of Medicine, Toronto, Canada
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20
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Detection of Cryptic Mosaicism in X-linked Alport Syndrome Prompts to Re-evaluate Living-donor Kidney Transplantation. Transplantation 2021; 104:2360-2364. [PMID: 31895869 DOI: 10.1097/tp.0000000000003104] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
BACKGROUND Alport syndrome is a hereditary nephropathy caused by mutations in collagen IV genes and characterized by ultrastructural lesions of the glomerular basement membrane. Some patients have a negative family history with apparently de novo mutations. Although somatic mosaicism has been postulated, as cryptic mosaicism cannot be detected from mutational screening on peripheral blood samples, cases in kidney-confined mosaic form have been missed. METHODS We report the case of a 24-year-old male patient with X-linked Alport syndrome diagnosis due to a COL4A5 pathogenic mutation (c.3334_3337dup [p.Gly1113Alafs25]). The same mutation had not been previously detected on a peripheral blood sample of maternal DNA. However, the mother, who was undertaking a clinical re-evaluation to take in consideration the possibility of a living-kidney transplantation, had experienced persistent microhematuria since the age of 10 years. RESULTS A next-generation sequencing approach performed on maternal DNA from both peripheral blood sample and urine-derived podocyte-lineage cells unmasked the COL4A5 mutation only in the podocyte-lineage cells. CONCLUSIONS This finding unveils an early postzygotic event which can explain both the renal involvement and germline mosaicism. It changes the inheritance risk for each pregnancy raising it to 50% and underlines the need for different clinical management in the mother. This seems to indicate that a case-by-case more cautious approach is needed with mother-to-son kidney transplants.
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21
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Odiatis C, Savva I, Pieri M, Ioannou P, Petrou P, Papagregoriou G, Antoniadou K, Makrides N, Stefanou C, Ljubanović DG, Nikolaou G, Borza DB, Stylianou K, Gross O, Deltas C. A glycine substitution in the collagenous domain of Col4a3 in mice recapitulates late onset Alport syndrome. Matrix Biol Plus 2020; 9:100053. [PMID: 33718859 PMCID: PMC7930875 DOI: 10.1016/j.mbplus.2020.100053] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 11/18/2020] [Accepted: 11/20/2020] [Indexed: 12/13/2022] Open
Abstract
Alport syndrome (AS) is a severe inherited glomerulopathy caused by mutations in the genes encoding the α-chains of type-IV collagen, the most abundant component of the extracellular glomerular basement membrane (GBM). Currently most AS mouse models are knockout models for one of the collagen-IV genes. In contrast, about half of AS patients have missense mutations, with single aminoacid substitutions of glycine being the most common. The only mouse model for AS with a homozygous knockin missense mutation, Col4a3-p.Gly1332Glu, was partly described before by our group. Here, a detailed in-depth description of the same mouse is presented, along with another compound heterozygous mouse that carries the glycine substitution in trans with a knockout allele. Both mice recapitulate essential features of AS, including shorten lifespan by 30–35%, increased proteinuria, increased serum urea and creatinine, pathognomonic alternate GBM thinning and thickening, and podocyte foot process effacement. Notably, glomeruli and tubuli respond differently to mutant collagen-IV protomers, with reduced expression in tubules but apparently normal in glomeruli. However, equally important is the fact that in the glomeruli the mutant α3-chain as well as the normal α4/α5 chains seem to undergo a cleavage at, or near the point of the mutation, possibly by the metalloproteinase MMP-9, producing a 35 kDa C-terminal fragment. These mouse models represent a good tool for better understanding the spectrum of molecular mechanisms governing collagen-IV nephropathies and could be used for pre-clinical studies aimed at better treatments for AS. Two mouse models were generated that recapitulate essential features of AS patients. Glomeruli and tubuli respond differently to mutant collagen IV protomers. The mutant colIV protomers in glomeruli probably undergo a cleavage process by MMP9. The two AS mouse models represent a good tool for studying collagen-IV nephropathies. These models could be used for pre-clinical studies aimed at better treatments.
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Key Words
- ARAS, autosomal recessive alport syndrome
- AS, alport syndrome
- Alport syndrome
- BSA, bovine serum albumin
- Collagen-IV
- EM, electron microscopy
- ESRD, end stage renal disease
- GBM, glomerular basement membrane
- Glomerular basement membrane
- Glycine missense mutation
- Kidney disease
- Mouse model
- PAS, periodic acid schiff
- TBM, tubular basement membrane
- TGF-b1, transforming growth factor beta1
- UPR, unfolded protein response
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Affiliation(s)
- Christoforos Odiatis
- Center of Excellence in Biobanking and Biomedical Research, Molecular Medicine Research Center, University of Cyprus Medical School, Cyprus
| | - Isavella Savva
- Center of Excellence in Biobanking and Biomedical Research, Molecular Medicine Research Center, University of Cyprus Medical School, Cyprus
| | - Myrtani Pieri
- Department of Life and Health Sciences, School of Sciences and Engineering, University of Nicosia, Cyprus
| | - Pavlos Ioannou
- Center of Excellence in Biobanking and Biomedical Research, Molecular Medicine Research Center, University of Cyprus Medical School, Cyprus
| | - Petros Petrou
- Department of Biochemistry, The Cyprus Institute of Neurology and Genetics, Cyprus
| | - Gregory Papagregoriou
- Center of Excellence in Biobanking and Biomedical Research, Molecular Medicine Research Center, University of Cyprus Medical School, Cyprus
| | - Kyriaki Antoniadou
- Center of Excellence in Biobanking and Biomedical Research, Molecular Medicine Research Center, University of Cyprus Medical School, Cyprus
| | - Neoklis Makrides
- Department of Developmental Functional Genetics, The Cyprus Institute of Neurology and Genetics, Cyprus
| | - Charalambos Stefanou
- Center of Excellence in Biobanking and Biomedical Research, Molecular Medicine Research Center, University of Cyprus Medical School, Cyprus
| | | | - Georgios Nikolaou
- Veterinary diagnostic laboratory, Vet ex Machina LTD, Nicosia, Cyprus
| | - Dorin-Bogdan Borza
- Dept. of Microbiology, Immunology and Physiology, Meharry Medical College, Nashville, TN, United States of America
| | - Kostas Stylianou
- Department of Nephrology, University of Crete Medical School, Greece
| | - Oliver Gross
- Clinic for Nephrology and Rheumatology, University Medical Center Göttingen, Göttingen, Germany
| | - Constantinos Deltas
- Center of Excellence in Biobanking and Biomedical Research, Molecular Medicine Research Center, University of Cyprus Medical School, Cyprus
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22
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Matthaiou A, Poulli T, Deltas C. Prevalence of clinical, pathological and molecular features of glomerular basement membrane nephropathy caused by COL4A3 or COL4A4 mutations: a systematic review. Clin Kidney J 2020; 13:1025-1036. [PMID: 33391746 PMCID: PMC7769542 DOI: 10.1093/ckj/sfz176] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 11/06/2019] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Patients heterozygous for COL4A3 or COL4A4 mutations show a wide spectrum of disease, extending from familial isolated microscopic haematuria, as a result of thin basement membranes (TBMs), to autosomal dominant Alport syndrome (ADAS) and end-stage renal disease (ESRD). Many patients are mentioned in the literature under the descriptive diagnosis of TBM nephropathy (TBMN), in which case it actually describes a histological finding that represents the carriers of autosomal recessive Alport syndrome (ARAS), a severe glomerulopathy, as most patients reach ESRD at a mean age of 25 years. METHODS We performed a systematic literature review for patients with heterozygous COL4A3/A4 mutations with the aim of recording the spectrum and frequency of pathological features. We searched three databases (PubMed, Embase and Scopus) using the keywords 'Autosomal Dominant Alport Syndrome' OR 'Thin Basement Membrane Disease' OR 'Thin Basement Membrane Nephropathy'. We identified 48 publications reporting on 777 patients from 258 families. RESULTS In total, 29% of the patients developed chronic kidney disease (CKD) and 15.1% reached ESRD at a mean age of 52.8 years. Extrarenal features and typical Alport syndrome (AS) findings had a low prevalence in patients as follows: hearing loss, 16%; ocular lesions, 3%; basement membrane thickening, 18.4%; and podocyte foot process effacement, 6.9%. Data for 76 patients from 54 families emphasize extensive inter- and intrafamilial heterogeneity, with age at onset of ESRD ranging between 21 and 84 years (mean 52.8). CONCLUSIONS The analysis enabled a comparison of the clinical course of patients with typical ARAS or X-linked AS with those with heterozygous COL4A mutations diagnosed with TBMN or ADAS. Despite the consequence of a potential ascertainment bias, an important outcome is that TBM poses a global high risk of developing severe CKD, over a long follow-up, with a variable spectrum of other findings. The results are useful to practicing nephrologists for better evaluation of patients.
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Affiliation(s)
| | | | - Constantinos Deltas
- Molecular Medicine Research Center and Laboratory of Molecular and Medical Genetics, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus
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23
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Fan LL, Liu L, Luo FM, Du R, Wang CY, Dong Y, Liu JS. A novel heterozygous variant of the COL4A4 gene in a Chinese family with hematuria and proteinuria leads to focal segmental glomerulosclerosis and chronic kidney disease. Mol Genet Genomic Med 2020; 8:e1545. [PMID: 33159707 PMCID: PMC7767549 DOI: 10.1002/mgg3.1545] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 09/14/2020] [Accepted: 10/16/2020] [Indexed: 01/15/2023] Open
Abstract
Background Focal segmental glomerulosclerosis (FSGS), as the frequent primary glomerular diseases in adults, accounts for symptomless proteinuria or nephrotic syndrome with or without renal insufficiency. As the crucial lesion of chronic kidney disease (CKD), accumulating evidence from recent studies show that mutations in Collagen‐related genes may be responsible for FSGS. The aim of this study was to identify the genetic lesion of a Chinese family with FSGS and CKD. Methods In this study, we recruited a Han‐Chinese family with unexplained high serum creatinine, hematuria, and proteinuria. Further renal biopsy and renal pathology indicated the diagnosis of FSGS in the proband. Whole‐exome sequencing and Sanger sequencing were employed to explore the pathogenic mutation of this family. Results A novel heterozygous mutation (NM_000092 c.2030G>A, p.G677D) of the collagen type IV alpha‐4 gene (COL4A4) was detected. Co‐segregation analysis revealed that the novel mutation was carried by all the five affected individuals and absent in other healthy members as well as in our 200 local control cohorts. Bioinformatics predication indicated that this novel mutation was pathogenic and may disrupt the structure and function of type IV collagen. Simultaneously, this variant is located in an evolutionarily conserved site of COL4A4 protein. Conclusion Here, we identified a novel mutation of COL4A4 in a family with FSGS and CKD. Our study expanded the variants spectrum of the COL4A4 gene and contributed to the genetic counseling and prenatal genetic diagnosis of the family. In addition, we also recommended the new classification of collagen IV nephropathies, which may be a benefit to the diagnosis, target drug treatment, and management of patients with COL4A3/COL4A4 mutations.
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Affiliation(s)
- Liang-Liang Fan
- Department of Nephrology, The Third Xiangya Hospital of Central South University, Changsha, China.,Department of Cell Biology, The School of Life Sciences, Central South University, Changsha, China.,Hunan Key Laboratory of Animal for Human Disease, School of Life Sciences, Central South University, Changsha, China
| | - Lv Liu
- Department of Respiratory Medicine, Diagnosis and Treatment Center of Respiratory Disease, the Second Xiangya Hospital of Central South University, Changsha, Hunan, China
| | - Fang-Mei Luo
- Department of Cell Biology, The School of Life Sciences, Central South University, Changsha, China.,Hunan Key Laboratory of Animal for Human Disease, School of Life Sciences, Central South University, Changsha, China
| | - Ran Du
- Department of Cell Biology, The School of Life Sciences, Central South University, Changsha, China.,Hunan Key Laboratory of Animal for Human Disease, School of Life Sciences, Central South University, Changsha, China
| | - Chen-Yu Wang
- Department of Cell Biology, The School of Life Sciences, Central South University, Changsha, China.,Hunan Key Laboratory of Animal for Human Disease, School of Life Sciences, Central South University, Changsha, China
| | - Yi Dong
- Department of Cell Biology, The School of Life Sciences, Central South University, Changsha, China.,Hunan Key Laboratory of Animal for Human Disease, School of Life Sciences, Central South University, Changsha, China
| | - Ji-Shi Liu
- Department of Nephrology, The Third Xiangya Hospital of Central South University, Changsha, China
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24
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Clark MM, Hildreth A, Batalov S, Ding Y, Chowdhury S, Watkins K, Ellsworth K, Camp B, Kint CI, Yacoubian C, Farnaes L, Bainbridge MN, Beebe C, Braun JJA, Bray M, Carroll J, Cakici JA, Caylor SA, Clarke C, Creed MP, Friedman J, Frith A, Gain R, Gaughran M, George S, Gilmer S, Gleeson J, Gore J, Grunenwald H, Hovey RL, Janes ML, Lin K, McDonagh PD, McBride K, Mulrooney P, Nahas S, Oh D, Oriol A, Puckett L, Rady Z, Reese MG, Ryu J, Salz L, Sanford E, Stewart L, Sweeney N, Tokita M, Van Der Kraan L, White S, Wigby K, Williams B, Wong T, Wright MS, Yamada C, Schols P, Reynders J, Hall K, Dimmock D, Veeraraghavan N, Defay T, Kingsmore SF. Diagnosis of genetic diseases in seriously ill children by rapid whole-genome sequencing and automated phenotyping and interpretation. Sci Transl Med 2020; 11:11/489/eaat6177. [PMID: 31019026 DOI: 10.1126/scitranslmed.aat6177] [Citation(s) in RCA: 156] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2018] [Revised: 10/24/2018] [Accepted: 04/01/2019] [Indexed: 12/19/2022]
Abstract
By informing timely targeted treatments, rapid whole-genome sequencing can improve the outcomes of seriously ill children with genetic diseases, particularly infants in neonatal and pediatric intensive care units (ICUs). The need for highly qualified professionals to decipher results, however, precludes widespread implementation. We describe a platform for population-scale, provisional diagnosis of genetic diseases with automated phenotyping and interpretation. Genome sequencing was expedited by bead-based genome library preparation directly from blood samples and sequencing of paired 100-nt reads in 15.5 hours. Clinical natural language processing (CNLP) automatically extracted children's deep phenomes from electronic health records with 80% precision and 93% recall. In 101 children with 105 genetic diseases, a mean of 4.3 CNLP-extracted phenotypic features matched the expected phenotypic features of those diseases, compared with a match of 0.9 phenotypic features used in manual interpretation. We automated provisional diagnosis by combining the ranking of the similarity of a patient's CNLP phenome with respect to the expected phenotypic features of all genetic diseases, together with the ranking of the pathogenicity of all of the patient's genomic variants. Automated, retrospective diagnoses concurred well with expert manual interpretation (97% recall and 99% precision in 95 children with 97 genetic diseases). Prospectively, our platform correctly diagnosed three of seven seriously ill ICU infants (100% precision and recall) with a mean time saving of 22:19 hours. In each case, the diagnosis affected treatment. Genome sequencing with automated phenotyping and interpretation in a median of 20:10 hours may increase adoption in ICUs and, thereby, timely implementation of precise treatments.
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Affiliation(s)
- Michelle M Clark
- Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA
| | - Amber Hildreth
- Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA.,Department of Pediatrics, University of California San Diego, San Diego, CA 92093, USA.,Department of Pediatrics, University of Washington, Seattle, WA 98195, USA
| | - Sergey Batalov
- Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA
| | - Yan Ding
- Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA
| | - Shimul Chowdhury
- Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA
| | - Kelly Watkins
- Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA
| | | | - Brandon Camp
- Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA
| | | | | | - Lauge Farnaes
- Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA.,Department of Pediatrics, University of California San Diego, San Diego, CA 92093, USA
| | - Matthew N Bainbridge
- Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA.,Codified Genomics, LLC, Houston, TX 77033, USA
| | - Curtis Beebe
- Rady Children's Hospital, San Diego, CA 92123, USA
| | - Joshua J A Braun
- Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA
| | - Margaret Bray
- Alexion Pharmaceuticals Inc., New Haven, CT 06510, USA
| | - Jeanne Carroll
- Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA.,Department of Pediatrics, University of California San Diego, San Diego, CA 92093, USA
| | - Julie A Cakici
- Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA
| | - Sara A Caylor
- Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA
| | - Christina Clarke
- Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA
| | - Mitchell P Creed
- University of Kansas School of Medicine, Kansas City, MO 66160, USA
| | - Jennifer Friedman
- Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA.,Department of Neurosciences, University of California San Diego, San Diego, CA 92093, USA
| | | | | | - Mary Gaughran
- Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA
| | | | | | - Joseph Gleeson
- Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA.,Department of Neurosciences, University of California San Diego, San Diego, CA 92093, USA
| | | | | | - Raymond L Hovey
- Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA
| | - Marie L Janes
- Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA
| | - Kejia Lin
- Rady Children's Hospital, San Diego, CA 92123, USA
| | | | - Kyle McBride
- Rady Children's Hospital, San Diego, CA 92123, USA
| | - Patrick Mulrooney
- Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA
| | - Shareef Nahas
- Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA
| | - Daeheon Oh
- Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA
| | - Albert Oriol
- Rady Children's Hospital, San Diego, CA 92123, USA
| | - Laura Puckett
- Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA
| | - Zia Rady
- Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA
| | | | - Julie Ryu
- Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA.,Department of Pediatrics, University of California San Diego, San Diego, CA 92093, USA
| | - Lisa Salz
- Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA
| | - Erica Sanford
- Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA.,Department of Pediatrics, University of California San Diego, San Diego, CA 92093, USA
| | | | - Nathaly Sweeney
- Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA.,Department of Pediatrics, University of California San Diego, San Diego, CA 92093, USA
| | - Mari Tokita
- Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA
| | - Luca Van Der Kraan
- Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA
| | - Sarah White
- Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA
| | - Kristen Wigby
- Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA.,Department of Pediatrics, University of California San Diego, San Diego, CA 92093, USA
| | | | - Terence Wong
- Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA
| | - Meredith S Wright
- Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA
| | - Catherine Yamada
- Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA
| | | | - John Reynders
- Alexion Pharmaceuticals Inc., New Haven, CT 06510, USA
| | | | - David Dimmock
- Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA
| | | | - Thomas Defay
- Alexion Pharmaceuticals Inc., New Haven, CT 06510, USA
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25
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Daga S, Donati F, Capitani K, Croci S, Tita R, Giliberti A, Valentino F, Benetti E, Fallerini C, Niccheri F, Baldassarri M, Mencarelli MA, Frullanti E, Furini S, Conticello SG, Renieri A, Pinto AM. New frontiers to cure Alport syndrome: COL4A3 and COL4A5 gene editing in podocyte-lineage cells. Eur J Hum Genet 2020; 28:480-490. [PMID: 31754267 PMCID: PMC7080842 DOI: 10.1038/s41431-019-0537-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 10/09/2019] [Accepted: 10/13/2019] [Indexed: 01/20/2023] Open
Abstract
Alport syndrome (AS) is an inherited genetic disorder characterized by range of alterations from glomerular basement membrane abnormalities up to end-stage renal disease. Pathogenic variants in the collagen α3, α4, and α5 encoding genes are causative both of the autosomal dominant and of the X-linked forms of AS. Podocytes are the only renal cells that are able to produce the COL(IV)a3-a4a5 heterotrimer. We have previously demonstrated how it is possible to isolate podocyte-lineage cells from urine of patients, providing an easily accessible cellular model closer to the podocytes' physiological conditions. Taking advantage of disease-relevant cell lines, we employed a two-plasmid approach in order to achieve a beneficial and stable variant-specific correction using CRISPR/Cas9 genome editing. One plasmid carries a Donor DNA and a reporter system mCherry/GFP to track the activity of Cas9 in cells. The other plasmid carries a self-cleaving SpCas9 and the variant-specific sgRNA. We have analyzed two stable podocyte-lineage cell lines, harboring a variant in the X-linked COL4A5 (p.(Gly624Asp)) and in the autosomal COL4A3 gene (p.(Gly856Glu)). We have achieved reversion of variants greater than 40% with undesired insertions/deletions lower than 15%. Overall, we have demonstrated a new gene therapy approach directly on patients' cells, key players of Alport pathogenesis, and we have reverted COL4 causative variants towards the wild type state. These results, in combination with preclinical models, could open new frontiers in the management and the treatment of the disorder.
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Affiliation(s)
- Sergio Daga
- 0000 0004 1757 4641grid.9024.fMedical Genetics, University of Siena, Siena, Italy
| | - Francesco Donati
- Core Research Laboratory, ISPRO, Florence, Italy ,0000 0004 1757 4641grid.9024.fDepartment of Medical Biotechnologies, University of Siena, Siena, Italy
| | - Katia Capitani
- Core Research Laboratory, ISPRO, Florence, Italy ,0000 0004 1757 4641grid.9024.fDepartment of Medical Biotechnologies, University of Siena, Siena, Italy
| | - Susanna Croci
- 0000 0004 1757 4641grid.9024.fMedical Genetics, University of Siena, Siena, Italy
| | - Rossella Tita
- 0000 0004 1759 0844grid.411477.0Genetica Medica, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Annarita Giliberti
- 0000 0004 1757 4641grid.9024.fMedical Genetics, University of Siena, Siena, Italy
| | - Floriana Valentino
- 0000 0004 1757 4641grid.9024.fMedical Genetics, University of Siena, Siena, Italy
| | - Elisa Benetti
- 0000 0004 1757 4641grid.9024.fMedical Genetics, University of Siena, Siena, Italy
| | - Chiara Fallerini
- 0000 0004 1757 4641grid.9024.fMedical Genetics, University of Siena, Siena, Italy
| | | | - Margherita Baldassarri
- 0000 0004 1759 0844grid.411477.0Genetica Medica, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | | | - Elisa Frullanti
- 0000 0004 1757 4641grid.9024.fMedical Genetics, University of Siena, Siena, Italy
| | - Simone Furini
- 0000 0004 1757 4641grid.9024.fDepartment of Medical Biotechnologies, University of Siena, Siena, Italy
| | | | - Alessandra Renieri
- 0000 0004 1757 4641grid.9024.fMedical Genetics, University of Siena, Siena, Italy ,0000 0004 1759 0844grid.411477.0Genetica Medica, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Anna Maria Pinto
- 0000 0004 1759 0844grid.411477.0Genetica Medica, Azienda Ospedaliera Universitaria Senese, Siena, Italy
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26
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Moustafa FEH, Eid R, Hamdy N. Pediatric glomerular hematuria: a clinicopathological study. Clin Exp Nephrol 2020; 24:613-621. [PMID: 32198715 DOI: 10.1007/s10157-020-01872-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2019] [Accepted: 03/03/2020] [Indexed: 11/25/2022]
Abstract
BACKGROUND Hematuria is a common problem in pediatric practice and necessitates exhausting studies to detect etiology and establish proper management and counselling. SUBJECTS AND METHODS We reviewed the clinical and pathological findings in 95 children presented between 2013 and 2019 with gross or microscopic hematuria with or without proteinuria in whom non-glomerular causes were excluded. In addition, a reference range for normal glomerular basement membrane thickness (GBMT) is introduced based on the assessment of biopsies of 20 steroid-resistant nephrotic syndrome cases aged 3-15 years, and with minimal change pathology. RESULTS Fifty-seven males and 38 females with a mean age of 7.72 ± 3.27 years were included. Recurrent gross hematuria was the most frequent presentation (42%) while accidentally discovered hematuria was reported in 34.7% of patients. Alport syndrome (AS) was the most frequent diagnosis (66.3%) followed by thin basement membrane disease (TBMD) (29.5%) and Immunoglobulin A nephropathy (IgAN) (4%). A reference for normal GBMT was 360.3 ± 87.5 nm which is comparable to published references. Males with AS had a higher incidence of progression to renal failure and requirement for dialysis (p = 0.006 and 0.03, respectively) compared to females. Persistent proteinuria and lower glomerular filtration rate at diagnosis were associated with poor outcomes (p < 0.001 each). CONCLUSION Alport Syndrome is the most common cause of glomerular hematuria in Egyptian children. Persistence of proteinuria and lower GFR at initial presentation were the main predictors of poor outcomes. The establishment of GBMT reference range for each locality is mandatory for the proper diagnosis of such cases.
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Affiliation(s)
| | - Riham Eid
- Pediatric Nephrology Unit, Departement of Pediatrics, Faculty of Medicine, Mansoura University, Mansoura, 35516, Egypt.
| | - Nashwa Hamdy
- Pediatric Nephrology Unit, Departement of Pediatrics, Faculty of Medicine, Mansoura University, Mansoura, 35516, Egypt
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27
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Endoplasmic reticulum stress and proteasome pathway involvement in human podocyte injury with a truncated COL4A3 mutation. Chin Med J (Engl) 2020; 132:1823-1832. [PMID: 31306228 PMCID: PMC6759124 DOI: 10.1097/cm9.0000000000000294] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Background: Collagen type IV (COL4)-related nephropathy includes a variety of kidney diseases that occur with or without extra-renal manifestations caused by COL4A3-5 mutations. Previous studies revealed several novel mutations, including three COL4A3 missense mutations (G619R, G801R, and C1616Y) and the COL4A3 chr:228172489delA c.4317delA p.Thr1440ProfsX87 frameshift mutation that resulted in a truncated NC1 domain (hereafter named COL4A3 c.4317delA); however, the mutation mechanisms that lead to podocyte injury remain unclear. This study aimed to further explore the mutation mechanisms that lead to podocyte injury. Methods: Wild-type (WT) and four mutant COL4A3 segments were constructed into a lentiviral plasmid, then stably transfected into human podocytes. Real-time polymerase chain reaction and Western blotting were applied to detect endoplasmic reticulum stress (ERS)- and apoptosis-related mRNA and protein levels. Then, human podocytes were treated with MG132 (a proteasome inhibitor) and brefeldin A (a transport protein inhibitor). The human podocyte findings were verified by the establishment of a mus-Col4a3 knockout mouse monoclonal podocyte using clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9) technology. Results: Our data showed that COL4A3 mRNA was significantly overexpressed in the lentivirus stably transfected podocytes. Moreover, the COL4A3 protein level was significantly increased in all groups except the COL4A3 c.4317delA group. Compared to the other test groups, the COL4A3 c.4317delA group showed excessive ERS and apoptosis. Podocytes treated with MG132 showed remarkably increased intra-cellular expression of the COL4A3 c.4317delA mutation. MG132 intervention improved higher ERS and apoptosis levels in the COL4A3 c.4317delA group. Mouse monoclonal podocytes with COL4A3 chr:82717932insA c.4852insA p.Arg1618ThrfsX4 were successfully acquired; this NC1-truncated mutation suggested a higher level of ERS and relatively remarkable level of apoptosis compared to that of the WT group. Conclusions: We demonstrated that excessive ERS and ERS-induced apoptosis were involved in the podocyte injury caused by the NC1-truncated COL4A3 mutation. Furthermore, proteasome pathway intervention might become a potential treatment for collagen type IV-related nephropathy caused by a severely truncated COL4A3 mutation.
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28
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Akihisa T, Sato M, Wakayama Y, Taneda S, Horita S, Hirose O, Makabe S, Kataoka H, Mori T, Sohara E, Uchida S, Nitta K, Mochizuki T. Glomerular Basement Membrane Protein Expression and the Diagnosis and Prognosis of Autosomal Dominant Alport Syndrome. Kidney Med 2019; 1:391-396. [PMID: 32734219 PMCID: PMC7380416 DOI: 10.1016/j.xkme.2019.06.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Alport syndrome is a hereditary glomerular nephritis associated with hearing loss and eye abnormalities and is classified as X-linked Alport syndrome, autosomal recessive Alport syndrome, and autosomal dominant Alport syndrome. Autosomal dominant Alport syndrome is caused by a mutation in the gene encoding type IV collagen α3 (α3[IV]); (COL4A3), or α4 (α4[IV]); (COL4A4). Autosomal dominant Alport syndrome progresses more gradually than male X-linked Alport syndrome and autosomal recessive Alport syndrome. Differentiating autosomal dominant Alport syndrome from thin basement membrane nephropathy, which shows better kidney prognosis, remains challenging. Because autosomal dominant Alport syndrome is linked to a heterozygous mutation, type IV collagen is produced by the wild-type allele, and all α(IV) chains are supposed to be normally expressed. In this study, the pathologic findings of a patient with Alport syndrome with a novel COL4A4 heterozygous nonsense mutation were investigated. We observed weaker staining of α5(IV) in the glomerular basement membrane and enhanced expressions of α2(IV), laminin, and fibronectin, which were assumed to be caused by compensatory mechanisms for lack of enough α3α4α5(IV) expression in the glomerular basement membrane. These findings may be useful not only for differentially diagnosing autosomal dominant Alport syndrome from thin basement membrane nephropathy, but also for determining the extent of progression and predicting kidney prognosis.
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Affiliation(s)
- Taro Akihisa
- Department of Medicine, Tokyo Medical and Dental University, Tokyo, Japan
| | - Masayo Sato
- Department of Medicine, Tokyo Medical and Dental University, Tokyo, Japan
| | - Yoshie Wakayama
- Department of Medicine, Tokyo Medical and Dental University, Tokyo, Japan
| | - Sekiko Taneda
- Division of Pathology, Tokyo Medical and Dental University, Tokyo, Japan
| | - Shigeru Horita
- Clinical Research Division for Polycystic Kidney Disease, Department of Medicine, Kidney Center, Tokyo Women's Medical University, Tokyo Medical and Dental University, Tokyo, Japan
| | - Orie Hirose
- Department of Pathology, Tokyo Medical and Dental University, Tokyo, Japan
| | - Shiho Makabe
- Department of Medicine, Tokyo Medical and Dental University, Tokyo, Japan
| | - Hiroshi Kataoka
- Department of Medicine, Tokyo Medical and Dental University, Tokyo, Japan.,Clinical Research Division for Polycystic Kidney Disease, Department of Medicine, Kidney Center, Tokyo Women's Medical University, Tokyo Medical and Dental University, Tokyo, Japan
| | - Takayasu Mori
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Eisei Sohara
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Shinichi Uchida
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Kosaku Nitta
- Department of Medicine, Tokyo Medical and Dental University, Tokyo, Japan
| | - Toshio Mochizuki
- Department of Medicine, Tokyo Medical and Dental University, Tokyo, Japan.,Clinical Research Division for Polycystic Kidney Disease, Department of Medicine, Kidney Center, Tokyo Women's Medical University, Tokyo Medical and Dental University, Tokyo, Japan
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29
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Zhao X, Chen C, Wei Y, Zhao G, Liu L, Wang C, Zhang J, Kong X. Novel mutations of COL4A3, COL4A4, and COL4A5 genes in Chinese patients with Alport Syndrome using next generation sequence technique. Mol Genet Genomic Med 2019; 7:e653. [PMID: 30968591 PMCID: PMC6565573 DOI: 10.1002/mgg3.653] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 01/23/2019] [Accepted: 03/04/2019] [Indexed: 01/01/2023] Open
Abstract
Background Alport syndrome (AS) is an inherited progressive renal disease caused by mutations in COL4A3, COL4A4, and COL4A5 genes. The large sizes of these genes and the absence of mutation hot spots have complicated mutational analysis by routine PCR‐based approaches. In recent years, the development of next‐generation sequencing (NGS) has made possible the time‐ and cost‐effective and accurate analysis of the three genes in a single step. Methods Here, we analyze COL4A3, COL4A4, and COL4A5 simultaneously in 29 AS patients using NGS. Candidate mutations were validated by classic Sanger sequencing and Real‐time PCR. Results Twenty two new mutations and 10 known mutations were detected. Of those novel mutations, 18, 3, and 1 mutations were detected in COL4A5, COL4A4, and COL4A3, respectively. Twenty six patients showed X‐linked inheritance, one showed autosomal recessive inheritance and two showed digenic inheritance (DI). Conclusion A comparison of the clinical manifestations caused by different types of mutations in COL4A5 suggested that large fragment mutations are relatively more severe than the other missense mutations and AS by some mutations may show inter‐ and intra‐familial phenotypic variability. It is important to consider these transmission patterns in the clinical evaluation according to the results of genetic testing, especially for DI. Twenty two new mutations can expand the genotypic spectrum of AS.
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Affiliation(s)
- Xuechao Zhao
- Genetics and Prenatal Diagnosis Center, The First Affiliated Hospital of Zhengzhou University, Henan Engineering Research Center for Gene Editing of Human Genetic Disease, Erqi District, Zhengzhou, China
| | - Chen Chen
- Genetics and Prenatal Diagnosis Center, The First Affiliated Hospital of Zhengzhou University, Henan Engineering Research Center for Gene Editing of Human Genetic Disease, Erqi District, Zhengzhou, China
| | - Yanfu Wei
- Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, Research Institute of Nephrology, Zhengzhou University, Zhengzhou, China
| | - Ganye Zhao
- Genetics and Prenatal Diagnosis Center, The First Affiliated Hospital of Zhengzhou University, Henan Engineering Research Center for Gene Editing of Human Genetic Disease, Erqi District, Zhengzhou, China
| | - Lina Liu
- Genetics and Prenatal Diagnosis Center, The First Affiliated Hospital of Zhengzhou University, Henan Engineering Research Center for Gene Editing of Human Genetic Disease, Erqi District, Zhengzhou, China
| | - Conghui Wang
- Genetics and Prenatal Diagnosis Center, The First Affiliated Hospital of Zhengzhou University, Henan Engineering Research Center for Gene Editing of Human Genetic Disease, Erqi District, Zhengzhou, China
| | - Junjun Zhang
- Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, Research Institute of Nephrology, Zhengzhou University, Zhengzhou, China
| | - Xiangdong Kong
- Genetics and Prenatal Diagnosis Center, The First Affiliated Hospital of Zhengzhou University, Henan Engineering Research Center for Gene Editing of Human Genetic Disease, Erqi District, Zhengzhou, China
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30
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Tabibzadeh N, Fleury D, Labatut D, Bridoux F, Lionet A, Jourde-Chiche N, Vrtovsnik F, Schlegel N, Vanhille P. MYH9-related disorders display heterogeneous kidney involvement and outcome. Clin Kidney J 2018; 12:494-502. [PMID: 31384440 PMCID: PMC6671426 DOI: 10.1093/ckj/sfy117] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Indexed: 11/14/2022] Open
Abstract
Background MYH9-related diseases (MYH9-RD) are autosomal dominant disorders caused by mutations of the MYH9 gene encoding the non-muscle myosin heavy chain IIA. They are characterized by congenital thrombocytopenia, giant platelets and leucocyte inclusions. Hearing impairment, pre-senile cataract and nephropathy can also occur. We aimed to evaluate renal involvement and outcome in MYH9-RD patients followed-up by nephrologists. Methods We conducted a retrospective multicentre observational study of 13 patients among 9 families with MYH9 mutation diagnosed by genetic testing and immunofluorescence assay referred to nephrologists. Results At initial referral, median age was 30 (range 14–76) years. Median estimated glomerular filtration rate was 66 mL/min/1.73 m2 (0–141) and two patients had already end-stage renal disease (ESRD). Renal presentation associated proteinuria (n = 12), haematuria (n = 6) and hypertension (n = 6). Three patients developed a rapid onset ESRD whereas five others had a relatively stable kidney function over a 3-year median follow-up (1–34). Extra-renal features varied widely, with hearing impairment in six patients, cataract in two and mild liver dysfunction in seven. Thrombocytopenia existed at referral in 11 patients. Time to diagnosis varied from 0 to 29 years (median 3 years). Initial diagnoses such as idiopathic thrombocytopenic purpura (n = 4) and focal segmental glomerulosclerosis (n = 1) led to corticosteroid administration (n = 4), intravenous immunoglobulins (n = 3), cyclophosphamide (n = 1) and splenectomy (n = 1). Conclusions Renal involvement and outcome in MYH9-RD are heterogeneous. The diagnosis is often delayed and misdiagnoses can lead to unnecessary treatments. MYH9-RD should be considered in any patient with glomerular involvement associated with a low or slightly decreased platelet count and/or hearing loss and liver dysfunction.
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Affiliation(s)
- Nahid Tabibzadeh
- Explorations Fonctionnelles Rénales, APHP Hôpital Bichat, DHU FIRE, CRI-Inserm U1149 et Université Paris Diderot, Paris, France
| | - Dominique Fleury
- Néphrologie et Médecine Interne, CH Valenciennes, Valenciennes, France
| | | | | | | | - Noémie Jourde-Chiche
- Aix-Marseille Univ, C2VN, INSERM 1263-INRA 1260, and AP-HM, Centre de Néphrologie et Transplantation Rénale, Hôpital de la Conception, Marseille, France
| | - François Vrtovsnik
- Néphrologie, APHP Hôpital Bichat, DHU FIRE, CRI-Inserm U1149 et Université Paris Diderot, Paris, France
| | - Nicole Schlegel
- CRCMH Pathologies Plaquettaires Robert Debré, APHP Hôpital Robert Debré, Paris, France
| | - Philippe Vanhille
- Néphrologie et Médecine Interne, CH Valenciennes, Valenciennes, France
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31
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Hashikami K, Asahina M, Nozu K, Iijima K, Nagata M, Takeyama M. Establishment of X-linked Alport syndrome model mice with a Col4a5 R471X mutation. Biochem Biophys Rep 2018; 17:81-86. [PMID: 30582011 PMCID: PMC6295608 DOI: 10.1016/j.bbrep.2018.12.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 12/06/2018] [Accepted: 12/06/2018] [Indexed: 11/25/2022] Open
Abstract
Alport syndrome (AS) is an inherited disorder characterized by glomerular basement membrane (GBM) abnormality and development of chronic kidney disease at an early age. The cause of AS is a genetic mutation in type IV collagen, and more than 80% of patients have X-linked AS (XLAS) with mutation in COL4A5. Although the causal gene has been identified, mechanisms of progression have not been elucidated, and no effective treatment has been developed. In this study, we generated a Col4a5 mutant mouse harboring a nonsense mutation (R471X) obtained from a patient with XLAS using clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated system. Col4a5 mRNA and protein expressions were not observed in the kidneys of hemizygous R471X male mice. R471X mice showed proteinuria and hematuria. Pathology revealed progression of glomerulosclerosis and interstitial fibrosis by age. Electron microscopy identified irregular thickening in GBM accompanied by irregular lamination. These observations were consistent with the clinical and pathological features of patients with AS and other established models. In addition, our mice models develop end-stage renal disease at the median age of 28 weeks, much later compared to previous models much more consistent with clinical course of human XLAS. Our models have advantages for future experiments in regard with treatment for human XLAS. Col4a5 R471X mutant mice with a mutation derived from a patient with XLAS were used. Hemizygous R471X male mice exhibited proteinuria and hematuria. Pathology revealed the progression of glomerulosclerosis and interstitial fibrosis. Electron microscopy identified irregular thickening in GBM. Pathological features of R471X mice were consistent with that of patients with AS.
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Key Words
- ALB, albumin
- AS, Alport syndrome
- Alport syndrome
- BUN, blood urea nitrogen
- CKD
- CKD, chronic kidney disease
- CRE, urinary creatinine
- CRISPR, clustered regularly interspaced short palindromic repeat
- Col4a5
- ESRD
- ESRD, end-stage renal disease
- GBM, glomerular basement membrane
- Model mice
- PCR, polymerase chain reaction
- XLAS
- XLAS, X-linked AS
- qPCR, quantitative PCR
- sgRNA, single-guide RNA
- ssODN, single-stranded oligodeoxynucleotide
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Affiliation(s)
- Kentarou Hashikami
- Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, 2-26-1, Muraoka-Higashi, Fujisawa, Kanagawa, 251-8555, Japan
| | - Makoto Asahina
- Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, 2-26-1, Muraoka-Higashi, Fujisawa, Kanagawa, 251-8555, Japan
| | - Kandai Nozu
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Hyogo 651-0017, Japan
| | - Kazumoto Iijima
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Hyogo 651-0017, Japan
| | - Michio Nagata
- Department of Kidney and Vascular Pathology, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Michiyasu Takeyama
- Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, 2-26-1, Muraoka-Higashi, Fujisawa, Kanagawa, 251-8555, Japan
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32
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Savige J. Should We Diagnose Autosomal Dominant Alport Syndrome When There Is a Pathogenic Heterozygous COL4A3 or COL4A4 Variant? Kidney Int Rep 2018; 3:1239-1241. [PMID: 30450445 PMCID: PMC6224634 DOI: 10.1016/j.ekir.2018.08.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Affiliation(s)
- Judy Savige
- Department of Medicine (Melbourne Health) and Northern Health, The University of Melbourne, Parkville, Victoria, Australia
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33
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Mutation analysis of COL4A3 and COL4A4 genes in a Chinese autosomal-dominant Alport syndrome family. J Genet 2018; 96:389-392. [PMID: 28674241 DOI: 10.1007/s12041-017-0786-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Autosomal dominant Alport syndrome (ADAS) accounts for 5% of all cases of Alport syndrome (AS), a primary basement membrane disorder arising from mutations in genes encoding the type IV collagen protein family.Mutations in COL4A3 and COL4A4 genes were reported to be associated with ADAS. In this study, clinical data in a large consanguineous family with seven affected members were reviewed, and genomic DNA was extracted. For mutation screening, all exons of COL4A3 and COL4A4 genes were polymerase chain reaction-amplified and direct sequenced from genomic DNA, and the mutations were analyzed by comparing with members in this family, 100 ethnicitymatched controls and the sequence of COL4A3 and COL4A4 genes from GenBank. A novel mutation determining a nucleotide change was found, i.e. c.4195 A>T (p.Met1399Leu) at 44th exon of COL4A4 gene, and this mutation showed heterozygous in all patients of this family. Also a novel intron mutation (c.4127+11 C>T) was observed at COL4A4 gene. Thus the novel missense mutation c.4195 A>T (p.Met1399Leu) and the intron mutation (c.4127+11 C>T) at COL4A4 gene might be responsible for ADAS of this family. Our results broadened the spectrum of mutations in COL4A4 and had important implications in the diagnosis, prognosis, and genetic counselling of ADAS.
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34
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Kashtan CE, Ding J, Garosi G, Heidet L, Massella L, Nakanishi K, Nozu K, Renieri A, Rheault M, Wang F, Gross O. Alport syndrome: a unified classification of genetic disorders of collagen IV α345: a position paper of the Alport Syndrome Classification Working Group. Kidney Int 2018; 93:1045-1051. [PMID: 29551517 DOI: 10.1016/j.kint.2017.12.018] [Citation(s) in RCA: 151] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 11/24/2017] [Accepted: 12/13/2017] [Indexed: 01/01/2023]
Abstract
Mutations in the genes COL4A3, COL4A4, and COL4A5 affect the synthesis, assembly, deposition, or function of the collagen IV α345 molecule, the major collagenous constituent of the mature mammalian glomerular basement membrane. These mutations are associated with a spectrum of nephropathy, from microscopic hematuria to progressive renal disease leading to ESRD, and with extrarenal manifestations such as sensorineural deafness and ocular anomalies. The existing nomenclature for these conditions is confusing and can delay institution of appropriate nephroprotective therapy. Herein we propose a new classification of genetic disorders of the collagen IV α345 molecule with the goal of improving renal outcomes through regular monitoring and early treatment.
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Affiliation(s)
- Clifford E Kashtan
- Department of Pediatrics, Division of Pediatric Nephrology, Alport Syndrome Treatments and Outcomes Registry, University of Minnesota Medical School and Masonic Children's Hospital, Minneapolis, Minnesota, USA.
| | - Jie Ding
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Guido Garosi
- Unita Operativa Complessa Nefrologia, Dialisi e Trapianto, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Laurence Heidet
- Asssitance Publique-Hôpitaux de Paris, Centre de Référence des Maladies Rénales Héréditaires de l'Enfant et de l'Adulte and Service de Néphrologie Pédiatrique, Hôpital Universitaire Necker-Enfants Malades, Paris, France
| | - Laura Massella
- Nephrology and Dialysis Unit, Pediatric Subspecialties Department, Bambino Gesu Children's Hospital, Istituto Di Ricovero e Cura a Carattere Scientifico, Rome, Italy
| | - Koichi Nakanishi
- Department of Child Health and Welfare (Pediatrics), Graduate School of Medicine, University of the Ryukus, Okinawa, Japan
| | - Kandai Nozu
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Alessandra Renieri
- Medical Genetics, University of Siena, Siena, Italy; Genetica Medica, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Michelle Rheault
- Department of Pediatrics, Division of Pediatric Nephrology, Alport Syndrome Treatments and Outcomes Registry, University of Minnesota Medical School and Masonic Children's Hospital, Minneapolis, Minnesota, USA
| | - Fang Wang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Oliver Gross
- Clinic of Nephrology and Rheumatology, University Medical Center Goettingen, University of Goettingen, Goettingen, Germany
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35
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Braunisch MC, Büttner-Herold M, Günthner R, Satanovskij R, Riedhammer KM, Herr PM, Klein HG, Wahl D, Küchle C, Renders L, Heemann U, Schmaderer C, Hoefele J. Heterozygous COL4A3 Variants in Histologically Diagnosed Focal Segmental Glomerulosclerosis. Front Pediatr 2018; 6:171. [PMID: 29946535 PMCID: PMC6007128 DOI: 10.3389/fped.2018.00171] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2018] [Accepted: 05/24/2018] [Indexed: 01/15/2023] Open
Abstract
Introduction: Steroid-resistant nephrotic syndrome (SRNS) is one of the most frequent causes for chronic kidney disease in childhood. In ~30% of these cases a genetic cause can be identified. The histological finding in SRNS is often focal segmental glomerulosclerosis (FSGS). In rare cases, however, pathogenic variants in genes associated with Alport syndrome can be identified in patients with the histological finding of FSGS. Materials and Methods: Clinical information was collected out of clinical reports and medical history. Focused molecular genetic analysis included sequencing of COL4A5 and COL4A3 in the index patient. Segregation analysis of identified variants was performed in the parents and children of the index patient. Results: The female index patient developed mild proteinuria and microscopic hematuria in childhood (12 years of age). The histological examination of the kidney biopsies performed at the age of 21, 28, and 32 years showed findings partly compatible with FSGS. However, immunosuppressive treatment of the index patient did not lead to a sufficient reduction of in part nephrotic-range proteinuria. After the patient developed hearing impairment at the age of 34 years and her daughter was diagnosed with microscopic hematuria at the age of 6 years, re-examination of the index's kidney biopsies by electron microscopy revealed textural changes of glomerular basement membrane compatible with Alport syndrome. Molecular genetic analysis identified two missense variants in COL4A3 in a compound heterozygous state with maternal and paternal inheritance. One of them is a novel variant that was also found in the 6 year old daughter of the index patient who presented with microscopic hematuria. Discussion: We were able to show that a novel variant combined with a previously described variant in compound heterozygous state resulted in a phenotype that was histologically associated with FSGS. Molecular genetic analysis therefore can be essential to solve difficult cases that show an unusual appearance and therefore improve diagnostic accuracy. Additionally, unnecessary and inefficient treatment with multiple side effects can be avoided.
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Affiliation(s)
- Matthias C Braunisch
- Department of Nephrology, Klinikum Rechts der Isar, Technical University of Munich, Munich, Germany.,Institute of Human Genetics, Klinikum Rechts der Isar, Technical University of Munich, Munich, Germany
| | - Maike Büttner-Herold
- Department of Nephropathology, Institute of Pathology, Friedrich-Alexander-University, Erlangen, Germany
| | - Roman Günthner
- Department of Nephrology, Klinikum Rechts der Isar, Technical University of Munich, Munich, Germany.,Institute of Human Genetics, Klinikum Rechts der Isar, Technical University of Munich, Munich, Germany
| | - Robin Satanovskij
- Department of Nephrology, Klinikum Rechts der Isar, Technical University of Munich, Munich, Germany.,Institute of Human Genetics, Klinikum Rechts der Isar, Technical University of Munich, Munich, Germany
| | - Korbinian M Riedhammer
- Department of Nephrology, Klinikum Rechts der Isar, Technical University of Munich, Munich, Germany.,Institute of Human Genetics, Klinikum Rechts der Isar, Technical University of Munich, Munich, Germany
| | - Pierre-Maurice Herr
- Institute of Human Genetics, Klinikum Rechts der Isar, Technical University of Munich, Munich, Germany
| | - Hanns-Georg Klein
- Center for Human Genetics and Laboratory Diagnostics Dr. Klein, Dr. Rost and Colleagues, Martinsried, Germany
| | - Dagmar Wahl
- Center for Human Genetics and Laboratory Diagnostics Dr. Klein, Dr. Rost and Colleagues, Martinsried, Germany
| | - Claudius Küchle
- Department of Nephrology, Klinikum Rechts der Isar, Technical University of Munich, Munich, Germany
| | - Lutz Renders
- Department of Nephrology, Klinikum Rechts der Isar, Technical University of Munich, Munich, Germany
| | - Uwe Heemann
- Department of Nephrology, Klinikum Rechts der Isar, Technical University of Munich, Munich, Germany
| | - Christoph Schmaderer
- Department of Nephrology, Klinikum Rechts der Isar, Technical University of Munich, Munich, Germany
| | - Julia Hoefele
- Institute of Human Genetics, Klinikum Rechts der Isar, Technical University of Munich, Munich, Germany
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Abstract
The glomerular basement membrane (GBM) is a specialized structure with a significant role in maintaining the glomerular filtration barrier. This GBM is formed from the fusion of two basement membranes during development and its function in the filtration barrier is achieved by key extracellular matrix components including type IV collagen, laminins, nidogens, and heparan sulfate proteoglycans. The characteristics of specific matrix isoforms such as laminin-521 (α5β2γ1) and the α3α4α5 chain of type IV collagen are essential for the formation of a mature GBM and the restricted tissue distribution of these isoforms makes the GBM a unique structure. Detailed investigation of the GBM has been driven by the identification of inherited abnormalities in matrix proteins and the need to understand pathogenic mechanisms causing severe glomerular disease. A well-described hereditary GBM disease is Alport syndrome, associated with a progressive glomerular disease, hearing loss, and lens defects due to mutations in the genes COL4A3, COL4A4, or COL4A5. Other proteins associated with inherited diseases of the GBM include laminin β2 in Pierson syndrome and LMX1B in nail patella syndrome. The knowledge of these genetic mutations associated with GBM defects has enhanced our understanding of cell-matrix signaling pathways affected in glomerular disease. This review will address current knowledge of GBM-associated abnormalities and related signaling pathways, as well as discussing the advances toward disease-targeted therapies for patients with glomerular disease.
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Affiliation(s)
- Christine Chew
- Faculty of Biology Medicine and Health, Wellcome Trust Centre for Cell-Matrix Research, Division of Cell Matrix Biology, School of Biological Sciences, University of Manchester, Manchester, United Kingdom
| | - Rachel Lennon
- Faculty of Biology Medicine and Health, Wellcome Trust Centre for Cell-Matrix Research, Division of Cell Matrix Biology, School of Biological Sciences, University of Manchester, Manchester, United Kingdom.,Department of Paediatric Nephrology, Royal Manchester Children's Hospital, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, United Kingdom
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37
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Urinary epidermal growth factor as a prognostic marker for the progression of Alport syndrome in children. Pediatr Nephrol 2018; 33:1731-1739. [PMID: 29948307 PMCID: PMC6132884 DOI: 10.1007/s00467-018-3988-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 05/21/2018] [Accepted: 05/25/2018] [Indexed: 11/21/2022]
Abstract
BACKGROUND Alport syndrome is a rare hereditary kidney disease manifested with progressive renal failure. Considerable variation exists in terms of disease progression among patients with Alport syndrome. Identification of patients at high risk of rapid progression remains an unmet need. Urinary epidermal growth factor (uEGF) has been shown to be independently associated with risk of progression to adverse kidney outcome in multiple independent adult chronic kidney disease (CKD) cohorts. In this study, we aim to assess if uEGF is associated with kidney impairment and its prognostic value for children with Alport syndrome. METHODS One hundred and seventeen pediatric patients with Alport syndrome and 146 healthy children (3-18 years old) were included in this study. uEGF was measured in duplicates in baseline urine samples using ELISA (R&D) and concentration was normalized by urine creatinine (uEGF/Cr). In patients with longitudinal follow-up data (n = 38), progression was defined as deteriorated kidney function (CKD stage increase) during follow-up period (follow-up length is about 31 months in average). The association of baseline uEGF/Cr level with estimated glomerular filtration rate (eGFR) slope and Alport syndrome patients' progression to a more advanced CKD stage during the follow-up period was used to evaluate the prognostic value of the marker. RESULTS We found that uEGF/creatinine (uEGF/Cr) decreases with age in pediatric patients with Alport syndrome with a significantly faster rate than in healthy children of the same age group. uEGF/Cr is significantly correlated with eGFR (r = 0.75, p < 0.001), after adjustment for age. In 38 patients with longitudinal follow-up, we observed a significant correlation between uEGF/Cr and eGFR slope (r = 0.58, p < 0.001). Patients with lower uEGF/Cr level were at increased risk of progression to a higher CKD stage. uEGF/Cr was able to distinguish progressors from non-progressors with an AUC of 0.88, versus 0.77 by eGFR and 0.81 by 24-h urinary protein (24-h UP). CONCLUSIONS Our study suggests that uEGF/Cr is a promising biomarker for accelerated kidney function decline in pediatric patients with Alport syndrome. It may help to identify patients at high risk of progression for targeted clinical care and improve the patients' stratification in interventional trials.
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Cervera-Acedo C, Coloma A, Huarte-Loza E, Sierra-Carpio M, Domínguez-Garrido E. Phenotype variability in a large Spanish family with Alport syndrome associated with novel mutations in COL4A3 gene. BMC Nephrol 2017; 18:325. [PMID: 29089023 PMCID: PMC5664579 DOI: 10.1186/s12882-017-0735-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 09/25/2017] [Indexed: 11/30/2022] Open
Abstract
Background Alport syndrome is an inherited renal disorder characterized by glomerular basement membrane lesions with hematuria, proteinuria and frequent hearing defects and ocular abnormalities. The disease is associated with mutations in genes encoding α3, α4, or α5 chains of type IV collagen, namely COL4A3 and COL4A4 in chromosome 2 and COL4A5 in chromosome X. In contrast to the well-known X-linked and autosomal recessive phenotypes, there is very little information about the autosomal dominant. In view of the wide spectrum of phenotypes, an exact diagnosis is sometimes difficult to achieve. Methods We investigated a Spanish family with variable phenotype of autosomal dominant Alport syndrome using clinical, histological, and genetic analysis. Results Mutational analysis of COL4A3 and COL4A4 genes showed a novel heterozygous mutation (c. 998G > A; p.G333E) in exon 18 of the COL4A3 gene. Among relatives carrying the novel mutation, the clinical phenotype was variable. Two additional COL4A3 mutations were found, a Pro-Leu substitution in exon 48 (p.P1461L) and a Ser-Cys substitution in exon 49 (p.S1492C), non-pathogenics alone. Conclusion Carriers of p.G333E and p.P1461L or p.S1492C mutations in COL4A3 gene appear to be more severely affected than carriers of only p.G333E mutation, and the clinical findings has an earlier onset. In this way, we could speculate on a synergistic effect of compound heterozygosity that could explain the different phenotype observed in this family.
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Affiliation(s)
- C Cervera-Acedo
- Molecular Diagnostics Unit, Center for Biomedical Research (CIBIR), Fundación Rioja Salud, C/Piqueras 98, 26006, Logroño, La Rioja, Spain
| | - A Coloma
- Department of Nephrology, San Pedro Hospital, Logroño, La Rioja, Spain
| | - E Huarte-Loza
- Department of Nephrology, San Pedro Hospital, Logroño, La Rioja, Spain
| | - M Sierra-Carpio
- Department of Nephrology, San Pedro Hospital, Logroño, La Rioja, Spain
| | - E Domínguez-Garrido
- Molecular Diagnostics Unit, Center for Biomedical Research (CIBIR), Fundación Rioja Salud, C/Piqueras 98, 26006, Logroño, La Rioja, Spain.
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39
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Fallerini C, Baldassarri M, Trevisson E, Morbidoni V, La Manna A, Lazzarin R, Pasini A, Barbano G, Pinciaroli AR, Garosi G, Frullanti E, Pinto AM, Mencarelli MA, Mari F, Renieri A, Ariani F. Alport syndrome: impact of digenic inheritance in patients management. Clin Genet 2017; 92:34-44. [PMID: 27859054 DOI: 10.1111/cge.12919] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 11/02/2016] [Accepted: 11/03/2016] [Indexed: 11/28/2022]
Abstract
Alport syndrome (ATS) is a genetically heterogeneous nephropathy with considerable phenotypic variability and different transmission patterns, including monogenic (X-linked/autosomal) and digenic inheritance (DI). Here we present a new series of families with DI and we discuss the consequences for genetic counseling and risk assessment. Out of five families harboring variants in more than one COL4 gene detected by next generation sequencing (NGS), minigene-splicing assay allowed us to identify four as true digenic. Two families showed COL4A3/A4 mutations in cis, mimicking an autosomal dominant inheritance with a more severe phenotype and one showed COL4A3/A4 mutations in trans, mimicking an autosomal recessive inheritance with a less severe phenotype. In a fourth family, a de novo mutation (COL4A5) combined with an inherited mutation (COL4A3) triggered a more severe phenotype. A fifth family, predicted digenic on the basis of silico tools, rather showed monogenic X-linked inheritance due to a hypomorphic mutation, in accordance with a milder phenotype. In conclusion, this study highlights the impact of DI in ATS and explains the associated atypical presentations. More complex inheritance should be therefore considered when reviewing prognosis and recurrence risks. On the other side, these findings emphasize the importance to accompany NGS with splicing assays in order to avoid erroneous identification of at risk members.
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Affiliation(s)
- C Fallerini
- Medical Genetics, University of Siena, Siena, Italy
| | - M Baldassarri
- Medical Genetics, University of Siena, Siena, Italy.,Genetica Medica, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - E Trevisson
- Department of Woman and Child Health, University of Padova, Padova, Italy.,Istituto di Ricerca Pediatria, IRP, Città della Speranza, Padova, Italy
| | - V Morbidoni
- Department of Woman and Child Health, University of Padova, Padova, Italy.,Istituto di Ricerca Pediatria, IRP, Città della Speranza, Padova, Italy
| | - A La Manna
- Department of Pediatrics, Second University of Napoli, Napoli, Italy
| | - R Lazzarin
- Nephrology and Dialysis, Ospedale San Giacomo Apostolo, Castelfranco Veneto, Italy
| | - A Pasini
- Nephrology and Pediatric Dialysis, Ospedale S. Orsola Malpighi, Bologna, Italy
| | - G Barbano
- Renal immunopathology, Istituto Giannina Gaslini, Genova, Italy
| | - A R Pinciaroli
- Nephrology and Dialysis, Azienda Ospedaliera Pugliese Ciaccio, Catanzaro, Italy
| | - G Garosi
- Nephrology, Dialysis and Transplantation, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - E Frullanti
- Medical Genetics, University of Siena, Siena, Italy
| | - A M Pinto
- Medical Genetics, University of Siena, Siena, Italy.,Genetica Medica, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - M A Mencarelli
- Genetica Medica, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - F Mari
- Medical Genetics, University of Siena, Siena, Italy.,Genetica Medica, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - A Renieri
- Medical Genetics, University of Siena, Siena, Italy.,Genetica Medica, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - F Ariani
- Medical Genetics, University of Siena, Siena, Italy.,Genetica Medica, Azienda Ospedaliera Universitaria Senese, Siena, Italy
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40
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Langsford D, Tang M, Djurdjev O, Er L, Levin A. The Variability of Estimated Glomerular Filtration Rate Decline in Alport Syndrome. Can J Kidney Health Dis 2016; 3:2054358116679129. [PMID: 28781883 PMCID: PMC5518963 DOI: 10.1177/2054358116679129] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 09/12/2016] [Indexed: 11/17/2022] Open
Abstract
Background: A progressive trajectory toward renal failure is common in patients with Alport syndrome. Genotype-phenotype correlations have been well described; however, the natural history of the trajectory toward renal failure is not well described. Objective: The objective of this study is to describe the natural history of renal function decline in a cohort of Alport syndrome patients. Design: Retrospective observational cohort study. Setting: British Columbia, Canada, chronic renal disease registry 1995-2012. Patients: 37 biopsy proven Alport syndrome or hematuria with family history of Alport syndrome. Measurements: Serial estimated glomerular filtration rate (eGFR) Trajectory of renal decline described graphically by fitting a cubic smoothing spline to patient’s eGFR measures. Various time points within a trajectory were indexed, randomly sampled, and followed for 2 years to estimate portion of progressors (>5 mL/min/1.73 m2 /y decline), stable state (0-2 mL/min/1.73 m2 /y decline), and regressors (>2 mL/min/1.73 m2 /y incline). Methods: In this retrospective observational cohort study, participants were identified through a chronic renal disease registry in British Columbia, Canada, from 1995 to 2012. Inclusion criteria were biopsy proven or hematuria with a family history of Alport syndrome. Individual patients and family group members were studied. Trajectory of renal decline described graphically by fitting a cubic smoothing spline to patient’s serial estimated glomerular filtration rate (eGFR) measures. Various time points within a trajectory were indexed, randomly sampled, and followed for 2 years to estimate portion of progressors (>5 mL/min/1.73 m2/y decline), stable state (0-2 mL/min/1.73 m2/y decline), and regressors (>2 mL/min/1.73 m2/y incline). Limitations: Histological or genetic evidence of Alport syndrome is not available in all patients. Results: Median follow-up time was 48.2 months of 37 patients (78% male), with a median age of 36 (interquartile range [IQR], 18-47) and a median age of renal replacement therapy commencement (n = 23) of 38 (IQR = 20-52). Renal function changes were found to be heterogeneous overall, intra-individual and within families. Portion of progressors in eGFR 45-60 mL/min/1.73 m2 was 73.7% (SD, 10.3), whereas 23.6% (SD, 11.0) remained stable. Within eGFR 30-45 mL/min/1.73 m2, 45.6% (SD, 7.0) were progressors, whereas 53.4% (SD, 7.4) remained stable. A large portion of eGFR 15-30 mL/min/1.73 m2 patients were stable (54.8%; SD, 8.4), whereas 25.7% (SD, 7.1) progressed and 19.5% (SD, 5.6) regressed. Conclusions: The renal decline in Alport syndrome patients is heterogeneous which has implications for designing clinical trials of interventions.
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Affiliation(s)
| | | | | | - Lee Er
- BC Renal Agency, Vancouver, Canada
| | - Adeera Levin
- The University of British Columbia, Vancouver, Canada
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41
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Syndrome d’Alport : néphropathie héréditaire associée à des mutations dans les gènes codant les chaînes de collagène de type IV. Nephrol Ther 2016; 12:544-551. [DOI: 10.1016/j.nephro.2016.09.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Kamiyoshi N, Nozu K, Fu XJ, Morisada N, Nozu Y, Ye MJ, Imafuku A, Miura K, Yamamura T, Minamikawa S, Shono A, Ninchoji T, Morioka I, Nakanishi K, Yoshikawa N, Kaito H, Iijima K. Genetic, Clinical, and Pathologic Backgrounds of Patients with Autosomal Dominant Alport Syndrome. Clin J Am Soc Nephrol 2016; 11:1441-1449. [PMID: 27281700 PMCID: PMC4974872 DOI: 10.2215/cjn.01000116] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 04/15/2016] [Indexed: 01/15/2023]
Abstract
BACKGROUND AND OBJECTIVES Alport syndrome comprises a group of inherited heterogeneous disorders involving CKD, hearing loss, and ocular abnormalities. Autosomal dominant Alport syndrome caused by heterozygous mutations in collagen 4A3 and/or collagen 4A4 accounts for <5% of patients. However, the clinical, genetic, and pathologic backgrounds of patients with autosomal dominant Alport syndrome remain unclear. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS We conducted a retrospective analysis of 25 patients with genetically proven autosomal dominant Alport syndrome and their family members (a total of 72 patients) from 16 unrelated families. Patients with suspected Alport syndrome after pathologic examination who were referred from anywhere in Japan for genetic analysis from 2006 to 2015 were included in this study. Clinical, laboratory, and pathologic data were collected from medical records at the point of registration for genetic diagnosis. Genetic analysis was performed by targeted resequencing of 27 podocyte-related genes, including Alport-related collagen genes, to make a diagnosis of autosomal dominant Alport syndrome and identify modifier genes or double mutations. Clinical data were obtained from medical records. RESULTS The median renal survival time was 70 years, and the median age at first detection of proteinuria was 17 years old. There was one patient with hearing loss and one patient with ocular lesion. Among 16 patients who underwent kidney biopsy, three showed FSGS, and seven showed thinning without lamellation of the glomerular basement membrane. Five of 13 detected mutations were reported to be causative mutations for autosomal recessive Alport syndrome in previous studies. Two families possessed double mutations in both collagen 4A3 and collagen 4A4, but no modifier genes were detected among the other podocyte-related genes. CONCLUSIONS The renal phenotype of autosomal dominant Alport syndrome was much milder than that of autosomal recessive Alport syndrome or X-linked Alport syndrome in men. It may, thus, be difficult to make an accurate diagnosis of autosomal dominant Alport syndrome on the basis of clinical or pathologic findings. No modifier genes were identified among the known podocyte-related genes.
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Affiliation(s)
- Naohiro Kamiyoshi
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Kandai Nozu
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Xue Jun Fu
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Naoya Morisada
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Yoshimi Nozu
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Ming Juan Ye
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Aya Imafuku
- Department of Nephrology, Toranomon Hospital, Tokyo, Japan
| | - Kenichiro Miura
- Department of Pediatrics, The University of Tokyo, Tokyo, Japan; and
| | - Tomohiko Yamamura
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Shogo Minamikawa
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Akemi Shono
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Takeshi Ninchoji
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Ichiro Morioka
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Koichi Nakanishi
- Department of Pediatrics, Wakayama Medical University, Wakayama, Japan
| | | | - Hiroshi Kaito
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Kazumoto Iijima
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
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44
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Baek H, Lee SI, Park T, Cho M. The Transition from Thin Basement Membranes to Typical Alport Syndrome Morphology in Children. Fetal Pediatr Pathol 2016; 35:369-375. [PMID: 27410722 DOI: 10.1080/15513815.2016.1202362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Some children with thin basement membranes (TBM) turn out to have Alport syndrome (AS). In our population of 58 children initially diagnosed with TBM, three were eventually diagnosed with AS. As a group, these three were first biopsied at a younger age, and had gross rather than microscopic hematuria. Only one had lamellations initially. Seven others had some degree of basement membrane lamellations at initial biopsy, but none of these have developed other features of AS. We concluded that at least 5% of children initially demonstrating TBM go on to manifest the classical electron-microscopic findings of AS during childhood. Episodes of gross hematuria with TBM can be a significant clue of AS. Genetic and/or immunofluorescent studies for type IV collagen, and continued long-term follow-up should be done in all children with TBM.
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Affiliation(s)
- Heesun Baek
- a Department of Pediatrics , Kyungpook National University School of Medicine , Daegu , Republic of Korea
| | - Sang-In Lee
- a Department of Pediatrics , Kyungpook National University School of Medicine , Daegu , Republic of Korea
| | - Taein Park
- b Department of Pathology , Kyungpook National University School of Medicine , Daegu , Republic of Korea
| | - Minhyun Cho
- a Department of Pediatrics , Kyungpook National University School of Medicine , Daegu , Republic of Korea
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45
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Deltas C, Savva I, Voskarides K, Papazachariou L, Pierides A. Carriers of Autosomal Recessive Alport Syndrome with Thin Basement Membrane Nephropathy Presenting as Focal Segmental Glomerulosclerosis in Later Life. Nephron Clin Pract 2015. [PMID: 26201269 DOI: 10.1159/000435789] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Collagen IV nephropathies (COL4Ns) comprise benign familial microscopic hematuria, thin basement membrane nephropathy (TBMN), X-linked Alport syndrome (AS) and also autosomal recessive and dominant AS. Apart from the X-linked form of AS, which is caused by hemizygous mutations in the COL4A5 gene, the other entities are caused by mutations in the COL4A3 or COL4A4 genes. The diagnosis of these conditions used to be based on clinical and/or histological findings of renal biopsies, but it is the new molecular genetics approach that revolutionised their investigation and proved particularly instrumental, especially, in many not so clear-cut cases. More recently, the spectrum of COL4N has expanded to include late onset focal segmental glomerulosclerosis (FSGS) that develops on top of TBMN in later life. Also, other reports showed that some patients with a primary diagnosis of familial FSGS proved to have variants in COL4 genes. In the presence of a renal biopsy picture of FSGS and in the absence of either electron microscopy studies or molecular genetic studies that point to TBMN and COL4N, the patient and his family may be mistakenly diagnosed with hereditary FSGS leading to unnecessary further investigations, erroneous family counselling and improper corticosteroid treatment. TBMN is a frequent finding in the general population, and according to several recent reports, it may be the underlying cause and the explanation for many familial and sporadic cases of late-onset FSGS with non-nephrotic proteinuria. This is an important new finding that needs widespread recognition. It is anticipated that the molecular genetic analysis with next generation sequencing will certainly offer timely correct diagnosis.
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Affiliation(s)
- Constantinos Deltas
- Molecular Medicine Research Center and Laboratory of Molecular and Medical Genetics, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus
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46
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Mencarelli MA, Heidet L, Storey H, van Geel M, Knebelmann B, Fallerini C, Miglietti N, Antonucci MF, Cetta F, Sayer JA, van den Wijngaard A, Yau S, Mari F, Bruttini M, Ariani F, Dahan K, Smeets B, Antignac C, Flinter F, Renieri A. Evidence of digenic inheritance in Alport syndrome. J Med Genet 2015; 52:163-74. [PMID: 25575550 DOI: 10.1136/jmedgenet-2014-102822] [Citation(s) in RCA: 107] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Alport syndrome is a clinically heterogeneous, progressive nephropathy caused by mutations in collagen IV genes, namely COL4A3 and COL4A4 on chromosome 2 and COL4A5 on chromosome X. The wide phenotypic variability and the presence of incomplete penetrance suggest that a simple Mendelian model cannot completely explain the genetic control of this disease. Therefore, we explored the possibility that Alport syndrome is under digenic control. METHODS Using massively parallel sequencing, we identified 11 patients who had pathogenic mutations in two collagen IV genes. For each proband, we ascertained the presence of the same mutations in up to 12 members of the extended family for a total of 56 persons studied. RESULTS Overall, 23 mutations were found. Individuals with two pathogenic mutations in different genes had a mean age of renal function deterioration intermediate with respect to the autosomal-dominant form and the autosomal-recessive one, in line with molecule stoichiometry of the disruption of the type IV collagen triple helix. CONCLUSIONS Segregation analysis indicated three possible digenic segregation models: (i) autosomal inheritance with mutations on different chromosomes, resembling recessive inheritance (five families); (ii) autosomal inheritance with mutations on the same chromosome resembling dominant inheritance (two families) and (iii) unlinked autosomal and X-linked inheritance having a peculiar segregation (four families). This pedigree analysis provides evidence for digenic inheritance of Alport syndrome. Clinical geneticists and nephrologists should be aware of this possibility in order to more accurately assess inheritance probabilities, predict prognosis and identify other family members at risk.
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Affiliation(s)
- Maria Antonietta Mencarelli
- Medical Genetics, University of Siena, Siena, Italy Genetica Medica, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Laurence Heidet
- APHP, Centre de Référence des Maladies Rénales Héréditaires de l'Enfant et de l'Adulte (MARHEA), Service de Néphrologie Pédiatrique, Hôpital Necker-Enfants Malades, Paris, France
| | - Helen Storey
- Molecular Genetics Laboratory, Guy's Hospital, London, UK
| | - Michel van Geel
- Clinical Genetics, Maastricht University Medical Centre, Maastricht, the Netherlands
| | - Bertrand Knebelmann
- APHP, Centre de Référence des Maladies Rénales Héréditaires de l'Enfant et de l'Adulte (MARHEA), Service de Néphrologie Pédiatrique, Hôpital Necker-Enfants Malades, Paris, France
| | | | - Nunzia Miglietti
- Clinica Pediatrica, Azienda Ospedaliera Spedali Civili, Brescia, Italy
| | | | | | - John A Sayer
- Institute of Genetic Medicine, Newcastle University, International Centre for Life, Central Parkway, Newcastle upon Tyne, UK
| | | | - Shu Yau
- Molecular Genetics Laboratory, Guy's Hospital, London, UK
| | - Francesca Mari
- Medical Genetics, University of Siena, Siena, Italy Genetica Medica, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Mirella Bruttini
- Medical Genetics, University of Siena, Siena, Italy Genetica Medica, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Francesca Ariani
- Medical Genetics, University of Siena, Siena, Italy Genetica Medica, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Karin Dahan
- Université Catholique de Louvain, Louvain, Belgium
| | - Bert Smeets
- Clinical Genetics, Maastricht University Medical Centre, Maastricht, the Netherlands
| | - Corinne Antignac
- Inserm UMR 1163, Laboratory of Inherited Kidney Diseases, Paris, France Paris Descartes-Sorbonne Paris Cité Université, Imagine Institute, Paris, France APHP, Department of Genetics, Hôpital Necker-Enfants Malades, Paris, France
| | - Frances Flinter
- Department of Clinical Genetics, Guy's & St Thomas' NHS Foundation Trust, Guy's Hospital, London, UK
| | - Alessandra Renieri
- Medical Genetics, University of Siena, Siena, Italy Genetica Medica, Azienda Ospedaliera Universitaria Senese, Siena, Italy
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Nabais Sá MJ, Sampaio S, Oliveira A, Alves S, Moura CP, Silva SE, Castro R, Araújo JA, Rodrigues M, Neves F, Seabra J, Soares C, Gaspar MA, Tavares I, Freitas L, Sousa TC, Henriques AC, Costa FT, Morgado E, Sousa FT, Sousa JP, da Costa AG, Filipe R, Garrido J, Montalban J, Ponce P, Alves R, Faria B, Carvalho MF, Pestana M, Carvalho F, Oliveira JP. Collagen type IV-related nephropathies in Portugal: pathogenic COL4A5 mutations and clinical characterization of 22 families. Clin Genet 2014; 88:462-7. [PMID: 25307721 DOI: 10.1111/cge.12522] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Revised: 10/08/2014] [Accepted: 10/08/2014] [Indexed: 11/28/2022]
Abstract
Alport syndrome (AS) is caused by pathogenic mutations in the genes encoding α3, α4 or α5 chains of collagen IV (COL4A3/COL4A4/COL4A5), resulting in hematuria, chronic renal failure (CRF), sensorineural hearing loss (SNHL) and ocular abnormalities. Mutations in the X-linked COL4A5 gene have been identified in 85% of the families (XLAS). In this study, 22 of 60 probands (37%) of unrelated Portuguese families, with clinical diagnosis of AS and no evidence of autosomal inheritance, had pathogenic COL4A5 mutations detected by Sanger sequencing and/or multiplex-ligation probe amplification, of which 12 (57%) are novel. Males had more severe and earlier renal and extrarenal complications, but microscopic hematuria was a constant finding irrespective of gender. Nonsense and splice site mutations, as well as small and large deletions, were associated with younger age of onset of SNHL in males, and with higher risk of CRF and SNHL in females. Pathogenic COL4A3 or COL4A4 mutations were subsequently identified in more than half of the families without a pathogenic mutation in COL4A5. The lower than expected prevalence of XLAS in Portuguese families warrants the use of next-generation sequencing for simultaneous COL4A3/COL4A4/COL4A5 analysis, as first-tier approach to the genetic diagnosis of collagen type IV-related nephropathies.
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Affiliation(s)
- M J Nabais Sá
- Department of Genetics, Faculty of Medicine, Porto, Portugal.,Unit of Research and Development of Nephrology (FCT-725), Faculty of Medicine, University of Porto, Porto, Portugal
| | - S Sampaio
- Unit of Research and Development of Nephrology (FCT-725), Faculty of Medicine, University of Porto, Porto, Portugal.,Department of Nephrology, Porto, Portugal
| | - A Oliveira
- Department of Nephrology, Porto, Portugal
| | - S Alves
- Department of Genetics, Faculty of Medicine, Porto, Portugal
| | - C P Moura
- Department of Otolaryngology, Porto, Portugal.,Medical Genetics Outpatient Clinic, Porto, Portugal
| | - S E Silva
- Department of Ophthalmology, Hospital de São João, Porto, Portugal
| | - R Castro
- Department of Nephrology, Centro Hospitalar de Trás-os-Montes e Alto Douro, Vila Real, Portugal
| | - J A Araújo
- Department of Nephrology, Hospital dos Marmeleiros, Funchal, Portugal
| | - M Rodrigues
- Department of Medical Genetics, Hospital Dona Estefânia, Lisboa, Portugal
| | - F Neves
- Dialysis Clinic of Santarém, NephroCare-Portugal, Santarém, Portugal
| | - J Seabra
- Department of Nephrology, Centro Hospitalar Vila Nova de Gaia/Espinho, Vila Nova de Gaia, Portugal
| | - C Soares
- Department of Nephrology, Hospital de Braga, Braga, Portugal
| | - M A Gaspar
- Dialysis Clinic of Restelo, NephroCare-Portugal, Lisboa, Portugal
| | - I Tavares
- Unit of Research and Development of Nephrology (FCT-725), Faculty of Medicine, University of Porto, Porto, Portugal.,Dialysis Clinic of Santo Tirso, Uninefro, Santo Tirso, Portugal
| | - L Freitas
- Department of Nephrology, Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal
| | - T C Sousa
- Department of Nephrology, Hospital de São Teotónio, Viseu, Portugal.,Dialysis Clinic of Guarda, NephroCare-Portugal, Guarda, Portugal
| | - A C Henriques
- Dialysis Clinic of Braga, NephroCare-Portugal, Braga, Portugal
| | - F T Costa
- Department of Nephrology, Hospital Garcia de Orta, Almada, Portugal
| | - E Morgado
- Department of Nephrology, Hospital de Faro, Faro, Portugal
| | - F T Sousa
- Dialysis Clinic of Montijo, NephroCare-Portugal, Montijo, Portugal
| | - J P Sousa
- Department of Nephrology, Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal.,Dialysis Clinic of Coimbra, NephroCare-Portugal, Coimbra, Portugal
| | - A G da Costa
- Department of Nephrology, Hospital de Santa Maria, Lisboa, Portugal
| | - R Filipe
- Department of Nephrology, Hospital Amato Lusitano, Castelo Branco, Portugal
| | - J Garrido
- Department of Nephrology, Hospital de São Teotónio, Viseu, Portugal
| | - J Montalban
- Dialysis Clinic of Covilhã, NephroCare-Portugal, Covilhã, Portugal
| | - P Ponce
- Dialysis Clinic of Lumiar, NephroCare-Portugal, Lisboa, Portugal
| | - R Alves
- Dialysis Clinic of Viseu, NephroCare-Portugal, Viseu, Portugal
| | - B Faria
- Dialysis Clinic of Guarda, NephroCare-Portugal, Guarda, Portugal
| | - M F Carvalho
- Unit of Renal Morphology, Department of Nephrology, Hospital Curry Cabral, Lisboa, Portugal
| | - M Pestana
- Unit of Research and Development of Nephrology (FCT-725), Faculty of Medicine, University of Porto, Porto, Portugal.,Department of Nephrology, Porto, Portugal
| | - F Carvalho
- Department of Genetics, Faculty of Medicine, Porto, Portugal
| | - J P Oliveira
- Department of Genetics, Faculty of Medicine, Porto, Portugal.,Unit of Research and Development of Nephrology (FCT-725), Faculty of Medicine, University of Porto, Porto, Portugal.,Medical Genetics Outpatient Clinic, Porto, Portugal
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48
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Rare hereditary COL4A3/COL4A4 variants may be mistaken for familial focal segmental glomerulosclerosis. Kidney Int 2014; 86:1253-9. [PMID: 25229338 PMCID: PMC4245465 DOI: 10.1038/ki.2014.305] [Citation(s) in RCA: 156] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Revised: 07/09/2014] [Accepted: 07/17/2014] [Indexed: 12/12/2022]
Abstract
Focal segmental glomerulosclerosis (FSGS) is a histological lesion with many causes including inherited genetic defects with significant proteinuria being the predominant clinical finding at presentation. Mutations in COL4A3 and COL4A4 are known to cause Alport syndrome, thin basement membrane nephropathy, and to result in pathognomonic glomerular basement membrane findings. Secondary FSGS is known to develop in classic Alport Syndrome at later stages of the disease. Here, we present seven families with rare or novel variants in COL4A3 or COL4A4 (six with single and one with two heterozygous variants) from a cohort of 70 families with a diagnosis of hereditary FSGS. The predominant clinical findings at diagnosis were proteinuria associated with hematuria. In all seven families, there were individuals with nephrotic range proteinuria with histologic features of FSGS by light microscopy. In one family, electron microscopy showed thin glomerular basement membrane, but four other families had variable findings inconsistent with classical Alport nephritis. There was no recurrence of disease after kidney transplantation. Families with COL4A3 and COL4A4 variants that segregated with disease represent 10% of our cohort. Thus, COL4A3 and COL4A4 variants should be considered in the interpretation of next-generation sequencing data from such patients. Furthermore, this study illustrates the power of molecular genetic diagnostics in the clarification of renal phenotypes.
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49
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Mallett A, Tang W, Clayton PA, Stevenson S, McDonald SP, Hawley CM, Badve SV, Boudville N, Brown FG, Campbell SB, Johnson DW. End-stage kidney disease due to Alport syndrome: outcomes in 296 consecutive Australia and New Zealand Dialysis and Transplant Registry cases. Nephrol Dial Transplant 2014; 29:2277-86. [DOI: 10.1093/ndt/gfu254] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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50
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Morinière V, Dahan K, Hilbert P, Lison M, Lebbah S, Topa A, Bole-Feysot C, Pruvost S, Nitschke P, Plaisier E, Knebelmann B, Macher MA, Noel LH, Gubler MC, Antignac C, Heidet L. Improving mutation screening in familial hematuric nephropathies through next generation sequencing. J Am Soc Nephrol 2014; 25:2740-51. [PMID: 24854265 DOI: 10.1681/asn.2013080912] [Citation(s) in RCA: 105] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Alport syndrome is an inherited nephropathy associated with mutations in genes encoding type IV collagen chains present in the glomerular basement membrane. COL4A5 mutations are associated with the major X-linked form of the disease, and COL4A3 and COL4A4 mutations are associated with autosomal recessive and dominant forms (thought to be involved in 15% and 1%-5% of the families, respectively) and benign familial hematuria. Mutation screening of these three large genes is time-consuming and expensive. Here, we carried out a combination of multiplex PCR, amplicon quantification, and next generation sequencing (NGS) analysis of three genes in 101 unrelated patients. We identified 88 mutations and 6 variations of unknown significance on 116 alleles in 83 patients. Two additional indel mutations were found only by secondary Sanger sequencing, but they were easily identified retrospectively with the web-based sequence visualization tool Integrative Genomics Viewer. Altogether, 75 mutations were novel. Sequencing the three genes simultaneously was particularly advantageous as the mode of inheritance could not be determined with certainty in many instances. The proportion of mutations in COL4A3 and COL4A4 was notably high, and the autosomal dominant forms of Alport syndrome appear more frequently than reported previously. Finally, this approach allowed the identification of large COL4A3 and COL4A4 rearrangements not described previously. We conclude that NGS is efficient, reduces screening time and cost, and facilitates the provision of appropriate genetic counseling in Alport syndrome.
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Affiliation(s)
- Vincent Morinière
- Departments of Genetics, and Assistance Publique des Hôpitaux de Paris, Reference Center for Renal Hereditary Disease for Children and Adults (MARHEA), Paris, France
| | - Karin Dahan
- Department of Genetics, Institute of Pathology and Genetics, Gosselies, Belgium
| | - Pascale Hilbert
- Department of Genetics, Institute of Pathology and Genetics, Gosselies, Belgium
| | - Marieline Lison
- Department of Genetics, Institute of Pathology and Genetics, Gosselies, Belgium
| | - Said Lebbah
- Assistance Publique des Hôpitaux de Paris, Reference Center for Renal Hereditary Disease for Children and Adults (MARHEA), Paris, France
| | - Alexandra Topa
- Department of Clinical Genetics, Sahlgrenska University Hospital, Gothenburg, Sweden
| | | | | | - Patrick Nitschke
- Bioinformatics Platform, Paris Descartes-Sorbonne Paris Cité University, Paris, France
| | - Emmanuelle Plaisier
- Assistance Publique des Hôpitaux de Paris, Nephrology Service, Tenon Hospital, Paris, France
| | | | - Marie-Alice Macher
- Assistance Publique des Hôpitaux de Paris, Pediatric Nephrology Service, Robert Debré Hospital, Paris, France; and
| | | | - Marie-Claire Gubler
- Institut National de la Santé et de la Recherche Médicale, Inserm UMR 1163, Laboratory of Inherited Kidney Diseases, Imagine Institute, Paris, France
| | - Corinne Antignac
- Departments of Genetics, and Assistance Publique des Hôpitaux de Paris, Reference Center for Renal Hereditary Disease for Children and Adults (MARHEA), Paris, France; Institut National de la Santé et de la Recherche Médicale, Inserm UMR 1163, Laboratory of Inherited Kidney Diseases, Imagine Institute, Paris, France Paris Descartes-Sorbonne Paris Cité University, and
| | - Laurence Heidet
- Assistance Publique des Hôpitaux de Paris, Reference Center for Renal Hereditary Disease for Children and Adults (MARHEA), Paris, France; Pediatric Nephrology Service, Assistance Publique des Hôpitaux de Paris, Necker-Enfants Malades Hospital, Paris, France
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