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Zhu V, Huang T, Wang D, Colville D, Mack H, Savige J. Ocular manifestations of the genetic causes of focal and segmental glomerulosclerosis. Pediatr Nephrol 2024; 39:655-679. [PMID: 37578539 PMCID: PMC10817844 DOI: 10.1007/s00467-023-06073-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Revised: 06/11/2023] [Accepted: 06/19/2023] [Indexed: 08/15/2023]
Abstract
Genetic forms of focal and segmental glomerulosclerosis (FSGS) often have extra-renal manifestations. This study examined FSGS-associated genes from the Genomics England Renal proteinuria panel for reported and likely ocular features. Thirty-two of the 55 genes (58%) were associated with ocular abnormalities in human disease, and a further 12 (22%) were expressed in the retina or had an eye phenotype in mouse models. The commonest genes affected in congenital nephrotic syndrome (NPHS1, NPHS2, WT1, LAMB2, PAX2 but not PLCE1) may have ocular manifestations . Many genes affected in childhood-adolescent onset FSGS (NPHS1, NPHS2, WT1, LAMB2, SMARCAL1, NUP107 but not TRPC6 or PLCE1) have ocular features. The commonest genes affected in adult-onset FSGS (COL4A3-COL4A5, GLA ) have ocular abnormalities but not the other frequently affected genes (ACTN4, CD2AP, INF2, TRPC6). Common ocular associations of genetic FSGS include cataract, myopia, strabismus, ptosis and retinal atrophy. Mitochondrial forms of FSGS (MELAS, MIDD, Kearn's Sayre disease) are associated with retinal atrophy and inherited retinal degeneration. Some genetic kidney diseases (CAKUT, ciliopathies, tubulopathies) that result in secondary forms of FSGS also have ocular features. Ocular manifestations suggest a genetic basis for FSGS, often help identify the affected gene, and prompt genetic testing. In general, ocular abnormalities require early evaluation by an ophthalmologist, and sometimes, monitoring or treatment to improve vision or prevent visual loss from complications. In addition, the patient should be examined for other syndromic features and first degree family members assessed.
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Affiliation(s)
- Victor Zhu
- Department of Medicine (Melbourne Health and Northern Health), Royal Melbourne Hospital, The University of Melbourne, Parkville, VIC, 3050, Australia
| | - Tess Huang
- Department of Medicine (Melbourne Health and Northern Health), Royal Melbourne Hospital, The University of Melbourne, Parkville, VIC, 3050, Australia
| | - David Wang
- Department of Medicine (Melbourne Health and Northern Health), Royal Melbourne Hospital, The University of Melbourne, Parkville, VIC, 3050, Australia
| | - Deb Colville
- Department of Surgery, Royal Victorian Eye and Ear Hospital, The University of Melbourne, East Melbourne, VIC, 3002, Australia
| | - Heather Mack
- Department of Surgery, Royal Victorian Eye and Ear Hospital, The University of Melbourne, East Melbourne, VIC, 3002, Australia
| | - Judy Savige
- Department of Medicine (Melbourne Health and Northern Health), Royal Melbourne Hospital, The University of Melbourne, Parkville, VIC, 3050, Australia.
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Alshamrani AA, Magliyah M, Alkuraya FS, Alabdi L, Alfaadhel TA, Alsulaiman SM. Early-Onset Myopia and Retinal Detachment without Typical Microcoria or Severe Proteinuria due to a Novel LAMB2 Variant. Ophthalmol Retina 2024; 8:155-162. [PMID: 37678612 DOI: 10.1016/j.oret.2023.08.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2023] [Revised: 08/29/2023] [Accepted: 08/30/2023] [Indexed: 09/09/2023]
Abstract
PURPOSE To describe the ocular and renal features, as well as outcomes of retinal detachment repair, in patients with a novel, homozygous laminin β-2 (LAMB2) pathogenic variant. DESIGN Single-center retrospective chart review of patients with a homozygous variant, c.619T>C p.(Ser207Pro), in the LAMB2 gene. SUBJECTS Eleven patients (22 eyes) from 4 families. METHODS Demographic data and ocular findings were recorded. Patients were recalled for a detailed renal evaluation. MAIN OUTCOME MEASURES Ocular features, renal features, and outcomes of retinal detachment repair. RESULTS The mean age at presentation was 6.0 (range, 1-26) years. None of the study eyes had microcoria, and none of the patients had nephrotic-range proteinuria. The mean refraction and axial length were -7.9 diopters (range, -4.0 to -12.0 diopters) and 25.3 (range, 22.7-27.7) mm, respectively. Eleven eyes (50%) had cataract at presentation. Fifteen eyes had a clear view to the fundus and all showed tessellated myopic fundus, avascular peripheral retina evident clinically or on fluorescein angiography, and rudimentary fovea. Optic disc pallor was observed in 10 eyes (66.7%). Straightened retinal vessels, abnormal vascular emanation (situs inversus) from the optic disc, supernumerary vascular branching at the optic disc, and vascular tortuosity were observed in 10 (66.7%), 2 (13.4%), 2 (13.4%), and 2 (13.4%) eyes, respectively. Discrete areas of punched-out chorioretinal atrophy were observed in 4 (26.7%) eyes. Spectral-domain OCT showed retinal and choroidal thinning in 13 eyes (86.7%), retinoschisis temporal to the fovea in 2 eyes (13.4%), and rudimentary fovea in 15 eyes (100%). Among the 22 eyes, 14 eyes (63.6%) developed rhegmatogenous retinal detachment (RRD), mostly during childhood, of which 5 patients had bilateral RRD. Eight eyes were operated on and 6 (75%) achieved retinal reattachment at the last follow-up. The mean preoperative visual acuity was 20/300 and the mean postoperative visual acuity at the last follow-up was 20/400. CONCLUSIONS This study describes a distinct phenotype of LAMB2-related disease with a novel, homozygous LAMB2 variant, and further expands the spectrum of ophthalmic and renal features, and the molecular genetic basis, of LAMB2-related disease. Because the typical microcoria and nephrotic-range proteinuria might be absent, the retinal features can guide the diagnosis. FINANCIAL DISCLOSURE(S) The authors have no proprietary or commercial interest in any materials discussed in this article.
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Affiliation(s)
| | - Moustafa Magliyah
- Vitreoretinal Division, King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia; Department of Ophthalmology, Prince Mohammed Medical City, Aljouf, Saudi Arabia
| | - Fowzan S Alkuraya
- Department of Translational Genomics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Lama Alabdi
- Department of Translational Genomics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Talal A Alfaadhel
- Department of Medicine, College of Medicine, King Saud University, Riyadh, Saudi Arabia
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Kulczyk AW. Artificial intelligence and the analysis of cryo-EM data provide structural insight into the molecular mechanisms underlying LN-lamininopathies. Sci Rep 2023; 13:17825. [PMID: 37857770 PMCID: PMC10587063 DOI: 10.1038/s41598-023-45200-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 10/17/2023] [Indexed: 10/21/2023] Open
Abstract
Laminins (Lm) are major components of basement membranes (BM), which polymerize to form a planar lattice on cell surface. Genetic alternations of Lm affect their oligomerization patterns and lead to failures in BM assembly manifesting in a group of human disorders collectively defined as Lm N-terminal domain lamininopathies (LN-lamininopathies). We have employed a recently determined cryo-EM structure of the Lm polymer node, the basic repeating unit of the Lm lattice, along with structure prediction and modeling to systematically analyze structures of twenty-three pathogenic Lm polymer nodes implicated in human disease. Our analysis provides the detailed mechanistic explanation how Lm mutations lead to failures in Lm polymerization underlining LN-lamininopathies. We propose the new categorization scheme of LN-lamininopathies based on the insight gained from the structural analysis. Our results can help to facilitate rational drug design aiming in the treatment of Lm deficiencies.
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Affiliation(s)
- Arkadiusz W Kulczyk
- Institute for Quantitative Biomedicine, Rutgers University, 174 Frelinghuysen Road, Piscataway, NJ, 08854, USA.
- Department of Biochemistry & Microbiology, Rutgers University, 75 Lipman Drive, New Brunswick, NJ, 08901, USA.
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van Duijvenboden S, Ramírez J, Young WJ, Olczak KJ, Ahmed F, Alhammadi MJAY, Bell CG, Morris AP, Munroe PB. Integration of genetic fine-mapping and multi-omics data reveals candidate effector genes for hypertension. Am J Hum Genet 2023; 110:1718-1734. [PMID: 37683633 PMCID: PMC10577090 DOI: 10.1016/j.ajhg.2023.08.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 08/11/2023] [Accepted: 08/11/2023] [Indexed: 09/10/2023] Open
Abstract
Genome-wide association studies of blood pressure (BP) have identified >1,000 loci, but the effector genes and biological pathways at these loci are mostly unknown. Using published association summary statistics, we conducted annotation-informed fine-mapping incorporating tissue-specific chromatin segmentation and colocalization to identify causal variants and candidate effector genes for systolic BP, diastolic BP, and pulse pressure. We observed 532 distinct signals associated with ≥2 BP traits and 84 with all three. For >20% of signals, a single variant accounted for >75% posterior probability, 65 were missense variants in known (SLC39A8, ADRB2, and DBH) and previously unreported BP candidate genes (NRIP1 and MMP14). In disease-relevant tissues, we colocalized >80 and >400 distinct signals for each BP trait with cis-eQTLs and regulatory regions from promoter capture Hi-C, respectively. Integrating mouse, human disorder, gene expression and tissue abundance data, and literature review, we provide consolidated evidence for 436 BP candidate genes for future functional validation and discover several potential drug targets.
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Affiliation(s)
- Stefan van Duijvenboden
- William Harvey Research Institute, Barts and the London Faculty of Medicine and Dentistry, Queen Mary University of London, EC1M 6BQ London, UK; Institute of Cardiovascular Science, University College London, London, UK; Nuffield Department of Population Health, University of Oxford, Oxford, UK
| | - Julia Ramírez
- William Harvey Research Institute, Barts and the London Faculty of Medicine and Dentistry, Queen Mary University of London, EC1M 6BQ London, UK; Aragon Institute of Engineering Research, University of Zaragoza, Zaragoza, Spain; Centro de Investigación Biomédica en Red - Bioingeniería, Biomateriales y Nanomedicina, Zaragoza, Spain
| | - William J Young
- William Harvey Research Institute, Barts and the London Faculty of Medicine and Dentistry, Queen Mary University of London, EC1M 6BQ London, UK; Barts Heart Centre, St Bartholomew's Hospital, EC1A 7BE London, UK
| | - Kaya J Olczak
- William Harvey Research Institute, Barts and the London Faculty of Medicine and Dentistry, Queen Mary University of London, EC1M 6BQ London, UK
| | - Farah Ahmed
- William Harvey Research Institute, Barts and the London Faculty of Medicine and Dentistry, Queen Mary University of London, EC1M 6BQ London, UK
| | | | - Christopher G Bell
- William Harvey Research Institute, Barts and the London Faculty of Medicine and Dentistry, Queen Mary University of London, EC1M 6BQ London, UK
| | - Andrew P Morris
- Centre for Genetics and Genomics Versus Arthritis, Centre for Musculoskeletal Research, The University of Manchester, Manchester, UK; National Institute of Health and Care Research, Manchester Biomedical Research Centre, Manchester University NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK.
| | - Patricia B Munroe
- William Harvey Research Institute, Barts and the London Faculty of Medicine and Dentistry, Queen Mary University of London, EC1M 6BQ London, UK; National Institute of Health and Care Research, Barts Cardiovascular Biomedical Research Centre, Queen Mary University of London, EC1M 6BQ London, UK.
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Gooley K, Williams P, Mack H, Zhu V, Langsford D, Pianta T, Barit D, Mahmood K, Savige J. A comparison of the ocular features in Pierson and Alport syndrome: a case report and literature review. Ophthalmic Genet 2023; 44:417-422. [PMID: 37537573 DOI: 10.1080/13816810.2023.2240881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 06/24/2023] [Accepted: 07/20/2023] [Indexed: 08/05/2023]
Abstract
BACKGROUND Pierson syndrome and X-linked Alport syndrome result from pathogenic variants in LAMB2 and COL4A5, respectively, and both affect basement membranes in the kidney and the eye. This study describes the ocular features in an individual with a homozygous LAMB2 pathogenic variant and compares the reported abnormalities in Pierson syndrome with those in Alport syndrome. METHODS A 28-year-old man who developed kidney failure 10 years previously and subsequently had an atrial septal defect repair was suspected of having genetic kidney disease on the basis of his likely diagnosis of Focal and Segmental Glomerulosclerosis (FSGS), his young age at presentation, and his cardiac anomaly. He then underwent Whole Exome Sequencing and a formal ophthalmological examination. RESULTS The patient was found to have a homozygous Likely Pathogenic missense variant (p.(Arg1719Cys)) in LAMB2 consistent with the diagnosis of Pierson syndrome. He had normal visual acuity, normal optic globe and cornea size, and normal lens appearance on direct examination. Upon further testing, his cornea demonstrated central thinning. There was also increased corneal endothelial pleomorphism, a reduced foveal reflex, and a blunted foveal curvature, similar to the features seen in X-linked Alport syndrome. CONCLUSION Our patient had a later onset form of Pierson syndrome or "FSGS type 5, with or without ocular abnormalities," consistent with his "milder" LAMB2 missense variant. The resemblance of the ocular features in Pierson syndrome and X-linked Alport syndrome suggests that mutations in LAMB2 and COL4A5 have similar effects on basement membranes and the pathogenesis of ocular damage.
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Affiliation(s)
- Kieran Gooley
- Department of Medicine (Melbourne Health and Northern Health), The University of Melbourne, Parkville, Australia
| | - Peter Williams
- Department of Medicine (Melbourne Health and Northern Health), The University of Melbourne, Parkville, Australia
| | - Heather Mack
- Department of Ophthalmology, The University of Melbourne, East Melbourne, Australia
| | - Victor Zhu
- Department of Medicine (Melbourne Health and Northern Health), The University of Melbourne, Parkville, Australia
| | | | - Tim Pianta
- Renal Unit, Northern Health, Epping, Australia
| | - David Barit
- Renal Unit, Northern Health, Epping, Australia
| | - Khalid Mahmood
- Melbourne Bioinformatics, The University of Melbourne, Parkville, Australia
| | - Judy Savige
- Department of Medicine (Melbourne Health and Northern Health), The University of Melbourne, Parkville, Australia
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Suzuki R, Sakakibara N, Ichikawa Y, Kitakado H, Ueda C, Tanaka Y, Okada E, Kondo A, Ishiko S, Ishimori S, Nagano C, Yamamura T, Horinouchi T, Okamoto T, Nozu K. Systematic Review of Clinical Characteristics and Genotype-Phenotype Correlation in LAMB2-Associated Disease. Kidney Int Rep 2023; 8:1811-1821. [PMID: 37705905 PMCID: PMC10496080 DOI: 10.1016/j.ekir.2023.06.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 05/21/2023] [Accepted: 06/21/2023] [Indexed: 09/15/2023] Open
Abstract
Introduction Laminin subunit beta-2 (LAMB2)-associated disease, termed Pierson syndrome, presents with congenital nephrotic syndrome, ocular symptoms, and neuromuscular symptoms. In recent years, however, the widespread use of next-generation sequencing (NGS) has helped to discover a variety of phenotypes associated with this disease. Therefore, we conducted this systematic review. Methods A literature search of patients with LAMB2 variants was conducted, and 110 patients were investigated, including 12 of our patients. For genotype-phenotype correlation analyses, the extracted data were investigated for pathogenic variant types, the severity of nephropathy, and extrarenal symptoms. Survival analyses were also performed for the onset age of end-stage kidney disease (ESKD). Results Among all patients, 81 (78%) presented with congenital nephrotic syndrome, and 52 (55%) developed ESKD within 12 months. The median age at ESKD onset was 6.0 months. Kidney survival analysis showed that patients with biallelic truncating variants had a significantly earlier progression to ESKD than those with other variants (median age 1.2 months vs. 60.0 months, P < 0.05). Although the laminin N-terminal domain is functionally important in laminin proteins, and variants in the laminin N-terminal domain are said to result in a severe kidney phenotype such as earlier onset age and worse prognosis, there were no significant differences in onset age of nephropathy and progression to ESKD between patients with nontruncating variants located in the laminin N-terminal domain and those with variants located outside this domain. Conclusion This study revealed a diversity of LAMB2-associated diseases, characteristics of LAMB2 nephropathy, and genotype-phenotype correlations.
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Affiliation(s)
- Ryota Suzuki
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Nana Sakakibara
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Yuta Ichikawa
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Hideaki Kitakado
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Chika Ueda
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Yu Tanaka
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Eri Okada
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Atsushi Kondo
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Shinya Ishiko
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Shingo Ishimori
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - China Nagano
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Tomohiko Yamamura
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Tomoko Horinouchi
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Takayuki Okamoto
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Kandai Nozu
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
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Sambharia M, Rastogi P, Thomas CP. Monogenic focal segmental glomerulosclerosis: A conceptual framework for identification and management of a heterogeneous disease. Am J Med Genet C Semin Med Genet 2022; 190:377-398. [PMID: 35894442 PMCID: PMC9796580 DOI: 10.1002/ajmg.c.31990] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 05/31/2022] [Accepted: 06/30/2022] [Indexed: 01/29/2023]
Abstract
Focal segmental glomerulosclerosis (FSGS) is not a disease, rather a pattern of histological injury occurring from a variety of causes. The exact pathogenesis has yet to be fully elucidated but is likely varied based on the type of injury and the primary target of that injury. However, the approach to treatment is often based on the degree of podocyte foot process effacement and clinical presentation without sufficient attention paid to etiology. In this regard, there are many monogenic causes of FSGS with variable presentation from nephrotic syndrome with histological features of primary podocytopathy to more modest degrees of proteinuria with limited evidence of podocyte foot process injury. It is likely that genetic causes are largely underdiagnosed, as the role and the timing of genetic testing in FSGS is not established and genetic counseling, testing options, and interpretation of genotype in the context of phenotype may be outside the scope of practice for both nephrologists and geneticists. Yet most clinicians believe that a genetic diagnosis can lead to targeted therapy, limit the use of high-dose corticosteroids as a therapeutic trial, and allow the prediction of the natural history and risk for recurrence in the transplanted kidney. In this manuscript, we emphasize that genetic FSGS is not monolithic in its presentation, opine on the importance of genetic testing and provide an algorithmic approach to deployment of genetic testing in a timely fashion when faced with a patient with FSGS.
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Affiliation(s)
- Meenakshi Sambharia
- Division of Nephrology, Department of Internal MedicineUniversity of IowaIowa CityIowaUSA
| | - Prerna Rastogi
- Department of PathologyUniversity of IowaIowa CityIowaUSA
| | - Christie P. Thomas
- Division of Nephrology, Department of Internal MedicineUniversity of IowaIowa CityIowaUSA,Department of PediatricsUniversity of IowaIowa CityIowaUSA,The Iowa Institute of Human GeneticsUniversity of IowaIowa CityIowaUSA,Medical ServiceVeterans Affairs Medical CenterIowa CityIowaUSA
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Abstract
The laminins (LM) are a family of basement membranes glycoproteins with essential structural roles in supporting epithelia, endothelia, nerves and muscle adhesion, and signaling roles in regulating cell migration, proliferation, stem cell maintenance and differentiation. Laminins are obligate heterotrimers comprised of α, β and γ chains that assemble intracellularly. However, extracellularly these heterotrimers then assemble into higher-order networks via interaction between their laminin N-terminal (LN) domains. In vitro protein studies have identified assembly kinetics and the structural motifs involved in binding of adjacent LN domains. The physiological importance of these interactions has been identified through the study of pathogenic point mutations in LN domains that lead to syndromic disorders presenting with phenotypes dependent on which laminin gene is mutated. Genotype-phenotype comparison between knockout and LN domain missense mutations of the same laminin allows inferences to be drawn about the roles of laminin network assembly in terms of tissue function. In this review, we will discuss these comparisons in terms of laminin disorders, and the therapeutic options that understanding these processes have allowed. We will also discuss recent findings of non-laminin mediators of laminin network assembly and their implications in terms of basement membrane structure and function.
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Affiliation(s)
| | | | - Kevin J. Hamill
- Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, United Kingdom
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Ishizuka K, Miura K, Hashimoto T, Kaneko N, Harita Y, Yabuuchi T, Hisano M, Fujinaga S, Omori T, Yamaguchi Y, Hattori M. Degree of foot process effacement in patients with genetic focal segmental glomerulosclerosis: a single-center analysis and review of the literature. Sci Rep 2021; 11:12008. [PMID: 34103591 DOI: 10.1038/s41598-021-91520-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 05/25/2021] [Indexed: 01/15/2023] Open
Abstract
Determining the cause of focal segmental glomerulosclerosis (FSGS) has crucial implications for evaluating the risk of posttransplant recurrence. The degree of foot process effacement (FPE) on electron micrographs (EM) of native kidney biopsies can reportedly differentiate primary FSGS from secondary FSGS. However, no systematic evaluation of FPE in genetic FSGS has been performed. In this study, percentage of FPE and foot process width (FPW) in native kidney biopsies were analyzed in eight genetic FSGS patients and nine primary FSGS patients. All genetic FSGS patients showed segmental FPE up to 38% and FPW below 2000 nm, while all primary FSGS patients showed diffuse FPE above 88% and FPW above 3000 nm. We reviewed the literature which described the degree of FPE in genetic FSGS patients and identified 38 patients with a description of the degree of FPE. The degree of FPE in patients with mutations in the genes encoding proteins associated with slit diaphragm and cytoskeletal proteins was varied, while almost all patients with mutations in other FSGS genes showed segmental FPE. In conclusion, the present study suggests that the degree of FPE in native kidney biopsies may be useful for differentiating some genetic FSGS patients from primary FSGS patients.
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McKee KK, Hohenester E, Aleksandrova M, Yurchenco PD. Organization of the laminin polymer node. Matrix Biol 2021; 98:49-63. [PMID: 34029691 DOI: 10.1016/j.matbio.2021.05.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Revised: 05/14/2021] [Accepted: 05/15/2021] [Indexed: 12/13/2022]
Abstract
Laminin polymerization is a key step of basement membrane assembly that depends on the binding of α, β and γ N-terminal LN domains to form a polymer node. Nodal assembly can be divided into two steps consisting of β- and γ-LN dimerization followed by calcium-dependent addition of the α-LN domain. The assembly and structural organization of laminin-111 LN-LEa segments was examined by size-exclusion chromatography (SEC) and electron microscopy. Triskelion-like structures were observed in negatively-stained images of purified α1/β1/γ1 LN-LEa trimers. Image averaging of these revealed a heel-to-toe organization of the LN domains with angled outward projections of the LEa stem-like domains. A series of single-amino acid substitutions was introduced into the polymerization faces of the α1, β1 and γ1 LN domains followed by SEC analysis to distinguish between loss of β-γ mediated dimerization and loss of α-dependent trimerization (with intact β-γ dimers). Dimer-blocking mutations were confined to the γ1-toe and the β1-heel, whereas the trimer-only-blocking mutations mapped to the γ1-heel, β1-toe and the α1-toe and heel. Thus, in the polymer node the γ1-toe pairs with the β1-heel, the β1-toe pairs with the α1-heel, and the α1-toe pairs with the γ1-heel.
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Magliyah MS, Alsulaiman SM. Development of neovascular glaucoma after intraocular surgery in Pierson syndrome. Ophthalmic Genet 2021; 42:317-319. [PMID: 33554690 DOI: 10.1080/13816810.2021.1881982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Purpose: To report a patient with Pierson syndrome who presented with neovascular glaucoma (NVG) after cataract surgery.Methods: Retrospective case report.Results: A 17-year old monocular female presented with sudden onset of pain and decreased vision in the right eye. On examination, she had intraocular pressure (IOP) of 50 mmHg, aggressive iris neovascularization (NVI) and 3-piece IOL. Fundus examination revealed pale disc with tessellated fundus and parapapillary atrophy. Vascular arcades were vertically stretched with avascular ischemic retina starting from the near periphery. Macula appeared thin and atrophic. An intravitreal injection of 0.05 mg/0.1 ml bevacizumab was given to the right eye followed by Ahmed glaucoma valve (AGV) implantation. Assessment of her brother revealed similar posterior segment changes. A subsequent urine analysis showed proteinuria and high albumin to creatinine ratio. Next-generation sequencing for LAMB2 gene revealed a homozygous c.4573 + 1 G > A variant confirming the diagnosis of Pierson syndrome.Conclusion: This case expands our knowledge on retinal ischemia in the setting of Pierson syndrome. Close monitoring after intraocular surgery is recommended to look for the development of NVG.
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Affiliation(s)
- Moustafa S Magliyah
- Vitreoretinal Division, King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia.,Ophthalmology Department, Prince Mohammed Medical City, AlJouf, Saudi Arabia
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AlTaisan A, Magliyah M, Abouammoh MA, Taskintuna I, Alzahrani Y, Chang E, Alsulaiman SM. Posterior Segment Characterization in Children With Pierson Syndrome. Ophthalmic Surg Lasers Imaging Retina 2020; 51:618-627. [DOI: 10.3928/23258160-20201104-03] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 09/10/2020] [Indexed: 01/25/2023]
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Minamikawa S, Miwa S, Inagaki T, Nishiyama K, Kaito H, Ninchoji T, Yamamura T, Nagano C, Sakakibara N, Ishimori S, Hara S, Yoshikawa N, Hirano D, Harada R, Hamada R, Matsunoshita N, Nagata M, Shima Y, Nakanishi K, Nagase H, Takeda H, Morisada N, Iijima K, Nozu K. Molecular mechanisms determining severity in patients with Pierson syndrome. J Hum Genet 2020; 65:355-362. [PMID: 31959872 DOI: 10.1038/s10038-019-0715-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 12/10/2019] [Accepted: 12/11/2019] [Indexed: 01/15/2023]
Abstract
Null variants in LAMB2 cause Pierson syndrome (PS), a severe congenital nephrotic syndrome with ocular and neurological defects. Patients' kidney specimens show complete negativity for laminin β2 expression on glomerular basement membrane (GBM). In contrast, missense variants outside the laminin N-terminal (LN) domain in LAMB2 lead to milder phenotypes. However, we experienced cases not showing these typical genotype-phenotype correlations. In this paper, we report six PS patients: four with mild phenotypes and two with severe phenotypes. We conducted molecular studies including protein expression and transcript analyses. The results revealed that three of the four cases with milder phenotypes had missense variants located outside the LN domain and one of the two severe PS cases had a homozygous missense variant located in the LN domain; these variant positions could explain their phenotypes. However, one mild case possessed a splicing site variant (c.3797 + 5G>A) that should be associated with a severe phenotype. Upon transcript analysis, this variant generated some differently sized transcripts, including completely normal transcript, which could have conferred the milder phenotype. In one severe case, we detected the single-nucleotide substitution of c.4616G>A located outside the LN domain, which should be associated with a milder phenotype. However, we detected aberrant splicing caused by the creation of a novel splice site by this single-base substitution. These are novel mechanisms leading to an atypical genotype-phenotype correlation. In addition, all four cases with milder phenotypes showed laminin β2 expression on GBM. We identified novel mechanisms leading to atypical genotype-phenotype correlation in PS.
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Affiliation(s)
- Shogo Minamikawa
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Saori Miwa
- Department of Pediatrics, Jikei University School of Medicine, Tokyo, Japan
| | - Tetsuji Inagaki
- Department of Pediatric Nephrology, Miyagi Children's Hospital, Sendai, Japan
| | - Kei Nishiyama
- Department of Pediatrics, Graduate School of Medical Science, Kyushu University, Fukuoka, Japan
| | - Hiroshi Kaito
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Takeshi Ninchoji
- 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
| | - Shingo Ishimori
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Shigeo Hara
- Department of Diagnostic Pathology, Kobe City Medical Center General Hospital, Kobe, Japan
| | | | - Daishi Hirano
- Department of Pediatrics, Jikei University School of Medicine, Tokyo, Japan
| | - Ryoko Harada
- Department of Nephrology, Tokyo Metropolitan Children's Medical Center, Tokyo, Japan
| | - Riku Hamada
- Department of Nephrology, Tokyo Metropolitan Children's Medical Center, Tokyo, Japan
| | | | - Michio Nagata
- Department of Kidney and Vascular Pathology, Faculty of Medicine, University of Tsukuba, Tsukuba, 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, Nishihara, Japan
| | - Hiroaki Nagase
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Hiroki Takeda
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Naoya Morisada
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Kazumoto Iijima
- Department of Pediatrics, 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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Arima M, Tsukamoto S, Akiyama R, Nishiyama K, Kohno RI, Tachibana T, Hayashida A, Murayama M, Hisatomi T, Nozu K, Iijima K, Ohga S, Sonoda KH. Ocular findings in a case of Pierson syndrome with a novel mutation in laminin ß2 gene. J AAPOS 2018; 22:401-403.e1. [PMID: 30120985 DOI: 10.1016/j.jaapos.2018.03.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 03/14/2018] [Accepted: 03/15/2018] [Indexed: 11/16/2022]
Abstract
Pierson syndrome, an autosomal recessive disorder caused by a mutation in laminin ß2 (LAMB2) gene, is characterized by congenital nephrotic syndrome and various ocular abnormalities. The ocular findings in Pierson syndrome are not well understood, because the incidence of this syndrome is very rare. We report ocular findings in a 5-month-old boy with Pierson syndrome with a novel mutation in LAMB2. We performed a pupilloplasty for his microcoria. Ophthalmic examinations after surgery revealed that he had cataract, severe retinal degeneration, and high myopia. Optical coherence tomography showed the collapse of retinal layer structures and a marked decrease of choroidal thickness. Immunohistochemistry and electron microscopy examinations revealed abnormal iris differentiation and thinning or defect of basal membranes. These results suggest that the development of the iris, lens, retina, and choroid are affected in this type of mutation.
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Affiliation(s)
- Mitsuru Arima
- Department of Ophthalmology, Kyushu University Graduate School of Medical Sciences, Fukuoka City, Japan.
| | - Shoko Tsukamoto
- Department of Ophthalmology, Kyushu University Graduate School of Medical Sciences, Fukuoka City, Japan
| | - Rumi Akiyama
- Department of Ophthalmology, Kyushu University Graduate School of Medical Sciences, Fukuoka City, Japan
| | - Kei Nishiyama
- Department of Pediatrics, Kyushu University Graduate School of Medical Sciences, Fukuoka City, Japan
| | - Ri-Ichiro Kohno
- Department of Ophthalmology, Kyushu University Graduate School of Medical Sciences, Fukuoka City, Japan
| | - Takashi Tachibana
- Department of Ophthalmology, Kyushu University Graduate School of Medical Sciences, Fukuoka City, Japan
| | - Akira Hayashida
- Department of Ophthalmology, Kyushu University Graduate School of Medical Sciences, Fukuoka City, Japan
| | - Miwa Murayama
- Department of Ophthalmology, Kyushu University Graduate School of Medical Sciences, Fukuoka City, Japan
| | - Toshio Hisatomi
- Department of Ophthalmology, Kyushu University Graduate School of Medical Sciences, Fukuoka City, Japan
| | - Kandai Nozu
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe City, Japan
| | - Kazumoto Iijima
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe City, Japan
| | - Shouichi Ohga
- Department of Pediatrics, Kyushu University Graduate School of Medical Sciences, Fukuoka City, Japan
| | - Koh-Hei Sonoda
- Department of Ophthalmology, Kyushu University Graduate School of Medical Sciences, Fukuoka City, Japan
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McKee KK, Aleksandrova M, Yurchenco PD. Chimeric protein identification of dystrophic, Pierson and other laminin polymerization residues. Matrix Biol 2018; 67:32-46. [PMID: 29408412 PMCID: PMC5910262 DOI: 10.1016/j.matbio.2018.01.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Revised: 01/12/2018] [Accepted: 01/12/2018] [Indexed: 12/28/2022]
Abstract
Laminin polymerization is a key step of basement membrane self-assembly that depends on the binding of the three different N-terminal globular LN domains. Several mutations in the LN domains cause LAMA2-deficient muscular dystrophy and LAMB2-deficient Pierson syndrome. These mutations may affect polymerization. A novel approach to identify the amino acid residues required for polymerization has been applied to an analysis of these and other laminin LN mutations. The approach utilizes laminin-nidogen chimeric fusion proteins that bind to recombinant non-polymerizing laminins to provide a missing functional LN domain. Single amino acid substitutions introduced into these chimeras were tested to determine if polymerization activity and the ability to assemble on cell surfaces were lost. Several laminin-deficient muscular dystrophy mutations, renal Pierson syndrome mutations, and Drosophila mutations causing defects of heart development were identified as ones causing loss of laminin polymerization. In addition, two novel residues required for polymerization were identified in the laminin γ1 LN domain.
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Affiliation(s)
- Karen K McKee
- Department of Pathology and Laboratory Medicine, Rutgers University - Robert Wood Johnson Medical School, Piscataway, NJ 08854, United States
| | - Maya Aleksandrova
- Department of Pathology and Laboratory Medicine, Rutgers University - Robert Wood Johnson Medical School, Piscataway, NJ 08854, United States
| | - Peter D Yurchenco
- Department of Pathology and Laboratory Medicine, Rutgers University - Robert Wood Johnson Medical School, Piscataway, NJ 08854, United States.
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Beaufils C, Farlay D, Machuca-Gayet I, Fassier A, Zenker M, Freychet C, Bonnelye E, Bertholet-Thomas A, Ranchin B, Bacchetta J. Skeletal impairment in Pierson syndrome: Is there a role for lamininβ2 in bone physiology? Bone 2018; 106:187-193. [PMID: 29051055 DOI: 10.1016/j.bone.2017.10.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 10/10/2017] [Accepted: 10/12/2017] [Indexed: 01/15/2023]
Abstract
INTRODUCTION Pierson syndrome is caused by a mutation of LAMB2, encoding for laminin β2. Clinical phenotype is variable but usually associates congenital nephrotic syndrome (CNS) and ocular abnormalities. Neuromuscular impairment has also been described. METHODS We report on a 15-year old girl, suffering from Pierson Syndrome, who developed severe bone deformations during puberty. This patient initially displayed CNS and microcoria, leading to the clinical diagnosis of Pierson syndrome. Genetic analysis revealed a truncating mutation and a splice site mutation of LAMB2. The patient received a renal transplantation (R-Tx) at the age of 3. After R-Tx, renal evolution was simple, the patient receiving low-dose corticosteroids, tacrolimus and mycophenolate mofetil. At the age of 12, bone deformations progressively appeared. At the time of bone impairment, renal function was subnormal (glomerular filtration rate using iohexol clearance 50mL/min per 1.73m2), and parameters of calcium/phosphate metabolism were normal (calcium 2.45mmol/L, phosphorus 1.30mmol/L, PTH 81ng/L, ALP 334U/L, 25OH-D 73nmol/L). Radiographs showed major deformations such as scoliosis, genu varum and diffuse epiphyseal abnormalities. A high resolution scanner (HR-pQCT) was performed, demonstrating a bone of "normal low" quantity and quality; major radial and cubital deformations were observed. Stainings of laminin β2 were performed on bone and renal samples from the patient and healthy controls: as expected, laminin β2 was expressed in the control kidney but not in the patient's renal tissue, and a similar pattern was observed in bone. CONCLUSION This is the first case of skeletal impairment ever described in Pierson syndrome. Integrin α3β1, receptor for laminin β2, are found in podocytes and osteoblasts, and the observation of both the presence of laminin β2 staining in healthy bone and its absence in the patient's bone raises the question of a potential role of laminin β2 in bone physiology.
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Affiliation(s)
- Camille Beaufils
- Centre de Référence des Maladies Rénales Rares, Hôpital Femme Mère Enfant, Hospices, Civils de Lyon, 69677 Bron, France.
| | - Delphine Farlay
- INSERM, UMR 1033, Université Claude Bernard Lyon 1, Lyon, France
| | | | - Alice Fassier
- Service de Chirurgie Orthopédique Pédiatrique, Hôpital Femme Mère Enfant, Hospices Civils de Lyon, Bron, France
| | - Martin Zenker
- Institute of Human Genetics, University Hospital Magdeburg, Germany
| | - Caroline Freychet
- Centre de Référence des Maladies Rénales Rares, Hôpital Femme Mère Enfant, Hospices, Civils de Lyon, 69677 Bron, France
| | - Edith Bonnelye
- INSERM, UMR 1033, Université Claude Bernard Lyon 1, Lyon, France
| | - Aurélia Bertholet-Thomas
- Centre de Référence des Maladies Rénales Rares, Hôpital Femme Mère Enfant, Hospices, Civils de Lyon, 69677 Bron, France
| | - Bruno Ranchin
- Centre de Référence des Maladies Rénales Rares, Hôpital Femme Mère Enfant, Hospices, Civils de Lyon, 69677 Bron, France
| | - Justine Bacchetta
- Centre de Référence des Maladies Rénales Rares, Hôpital Femme Mère Enfant, Hospices, Civils de Lyon, 69677 Bron, France; INSERM, UMR 1033, Université Claude Bernard Lyon 1, Lyon, France; Service de Chirurgie Orthopédique Pédiatrique, Hôpital Femme Mère Enfant, Hospices Civils de Lyon, Bron, France; Institute of Human Genetics, University Hospital Magdeburg, Germany; Faculté de Médecine Lyon Est, Université de Lyon, France, Lyon.
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17
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Tao C, Zhang X. Retinal Proteoglycans Act as Cellular Receptors for Basement Membrane Assembly to Control Astrocyte Migration and Angiogenesis. Cell Rep 2017; 17:1832-1844. [PMID: 27829154 DOI: 10.1016/j.celrep.2016.10.035] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 09/16/2016] [Accepted: 10/12/2016] [Indexed: 10/20/2022] Open
Abstract
The basement membrane is crucial for cell polarity, adhesion, and motility, but how it is assembled on the cell surface remains unclear. Here, we find that ablation of glycosaminoglycan (GAG) side chains of proteoglycans in the neuroretina disrupts the retinal basement membrane, leading to arrested astrocyte migration and reduced angiogenesis. Using genetic deletion and time-lapse imaging, we show that retinal astrocytes require neuronal-derived PDGF as a chemoattractive cue and the retinal basement membrane as a migratory substrate. Genetic ablation of heparan sulfates does not produce the same defects as GAG null mutants. In contrast, enzymatic removal of heparan sulfates and chondroitin sulfates together inhibits de novo laminin network assembly. These results indicate that both heparan and chondroitin sulfate proteoglycans participate in retinal basement membrane assembly, thus promoting astrocyte migration and angiogenesis.
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Affiliation(s)
- Chenqi Tao
- Departments of Ophthalmology, Pathology and Cell Biology, Columbia University, New York, NY 10032, USA
| | - Xin Zhang
- Departments of Ophthalmology, Pathology and Cell Biology, Columbia University, New York, NY 10032, USA.
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Falix FA, Bennebroek CA, van der Zwaag B, Lapid-Gortzak R, Florquin S, Oosterveld MJ. A novel mutation of laminin β2 (LAMB2) in two siblings with renal failure. Eur J Pediatr 2017; 176:515-9. [PMID: 28188379 DOI: 10.1007/s00431-017-2871-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2016] [Revised: 01/28/2017] [Accepted: 02/02/2017] [Indexed: 01/15/2023]
Abstract
UNLABELLED This report describes a novel mutation of LAMB2, the gene associated with Pierson syndrome (microcoria-congenital nephrosis syndrome), in two female siblings. The c.970T>C p.(Cys324Arg) mutation in the LAMB2 gene affects one of the eight highly conserved cysteine residues within the first EGF-like module of the laminin β2 protein. These residues form disulfide bonds in order to achieve a correct 3D structure of the protein. The reported phenotype is considered a relatively mild variant of Pierson syndrome and is associated with later-onset (18 months) therapy-resistant nephrotic syndrome leading to renal failure, and ocular abnormalities consisting of high myopia, microcoria, diverse retinal abnormalities, hence a low level of visual acuity. Importantly, the reported LAMB2 mutation was associated with normal neurological development in both siblings. CONCLUSION this report presents the variability of the renal, ocular and neurological phenotypes associated with LAMB2 mutations and underscores the importance of ophthalmologic examination in all children with unexplained renal insufficiency or nephrotic syndrome. What is known • LAMB2 mutations are associated with Pierson syndrome • Pierson syndrome is associated with congenital nephrotic syndrome, microcoria and neurological deficits What is new • A novel mutation in the LAMB2 gene in two female siblings • Genotype and clinical phenotype description of a novel LAMB2 mutation.
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Abstract
Treatment and management of kidney disease currently presents an enormous global burden, and the application of nanotechnology principles to renal disease therapy, although still at an early stage, has profound transformative potential. The increasing translation of nanomedicines to the clinic, alongside research efforts in tissue regeneration and organ-on-a-chip investigations, are likely to provide novel solutions to treat kidney diseases. Our understanding of renal anatomy and of how the biological and physico-chemical properties of nanomedicines (the combination of a nanocarrier and a drug) influence their interactions with renal tissues has improved dramatically. Tailoring of nanomedicines in terms of kidney retention and binding to key membranes and cell populations associated with renal diseases is now possible and greatly enhances their localization, tolerability, and efficacy. This Review outlines nanomedicine characteristics central to improved targeting of renal cells and highlights the prospects, challenges, and opportunities of nanotechnology-mediated therapies for renal diseases.
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Zemrani B, Cachat F, Bonny O, Giannoni E, Durig J, Fellmann F, Chehade H. A novel LAMB2 gene mutation associated with a severe phenotype in a neonate with Pierson syndrome. Eur J Med Res 2016; 21:19. [PMID: 27130041 PMCID: PMC4851796 DOI: 10.1186/s40001-016-0215-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Accepted: 04/21/2016] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND Pierson syndrome (PS) is a rare autosomal recessive disorder, caused by mutations in the laminin β2 (LAMB2) gene. It is characterized by congenital nephrotic syndrome, microcoria, and neurodevelopmental deficits. Several mutations with genotype-phenotype correlations have been reported, often with great clinical variability. We hereby report a novel homozygous nonsense mutation in the LAMB2 gene, associated with a severe phenotype presentation. CASE DIAGNOSIS We describe a term male infant born from consanguineous parents. The mother previously lost three children in the neonatal period, secondary to undefined renal disease, had two spontaneous abortions, and gave birth to one healthy daughter. The index case presented at birth with bilateral microcoria, severe hypotonia, respiratory distress, and congenital nephrotic syndrome associated with anuria and severe renal failure requiring peritoneal dialysis. The patients' clinical follow-up was unfavorable, and the newborn died at 7 days of life, after withdrawal of life support. Genetic analysis revealed a homozygous nonsense mutation at position c.2890C>T causing a premature stop codon (p.R964*) in LAMB2 gene. CONCLUSION We here describe a novel nonsense homozygous mutation in LAMB2 gene causing a severe neonatal presentation of Pierson syndrome. This new mutation expands the genotype-phenotype spectrum of this rare disease and confirms that truncating mutations might be associated with severe clinical features.
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Affiliation(s)
- Boutaina Zemrani
- Division of Pediatric Nephrology, Department of Pediatrics, Lausanne University Hospital, Rue du Bugnon 46, 1011, Lausanne, Switzerland.
| | - François Cachat
- Division of Pediatric Nephrology, Department of Pediatrics, Lausanne University Hospital, Rue du Bugnon 46, 1011, Lausanne, Switzerland
| | - Olivier Bonny
- Service of Nephrology, Lausanne University Hospital, Rue du Bugnon 21, 1011, Lausanne, Switzerland
| | - Eric Giannoni
- Service of Neonatology, Lausanne University Hospital, Rue du Bugnon 46, 1011, Lausanne, Switzerland
| | - Jacques Durig
- Service of Ophthalmology, Lausanne University Hospital, Rue du Bugnon 46, 1011, Lausanne, Switzerland
| | - Florence Fellmann
- Service of Medical Genetics, Lausanne University Hospital, Rue du Bugnon 46, 1011, Lausanne, Switzerland
| | - Hassib Chehade
- Division of Pediatric Nephrology, Department of Pediatrics, Lausanne University Hospital, Rue du Bugnon 46, 1011, Lausanne, Switzerland
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Qiu L, Zhou J. Simultaneous mutations of LAMB2 and NPHP1genes in a Chinese girl with isolated congenital nephrotic syndrome: a case report. BMC Pediatr 2016; 16:44. [PMID: 27004562 PMCID: PMC4802576 DOI: 10.1186/s12887-016-0583-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2014] [Accepted: 03/14/2016] [Indexed: 12/16/2022] Open
Abstract
Background LAMB2 mutations cause Pierson syndrome (OMIM 609049), an autosomal recessive genetic disease typically characterized by congenital nephrotic syndrome (CNS) and early onset renal failure, as well as bilateral microcoria. NPHP1 mutations cause familial juvenile nephronophthisis type 1 (NPHP1, OMIM 256100), another autosomal recessive renal disease that usually occurs years after birth. Both Pierson syndrome and nephronophthisis cause end-stage renal disease and rare kidney diseases in children. We report an extremely rare case of concurrent mutations of LAMB2 and NPHP1 in a Chinese girl with isolated CNS and the association of the phenotype with novel non-truncating mutations of LAMB2. Case presentation A-34-day-old girl presented with CNS but no eye abnormalities, and mild hyperechogenicity of kidneys. A novel c.1176_1178delTCT mutation caused deletion of a glycine in exon 9 of LAMB2, and another mutation c.4923 + 2 T > G led to a splicing error. In addition, compound heterozygous mutations of NPHP1 were identified in this child using next generation sequencing, and confirmed by Sanger sequencing. Conclusion Mutations of the LAMB2 and NPHP1 are present in infants with isolated CNS. Next generation sequencing enabled high-throughput screening for mutant genes promptly, with clinically significant outcomes. In addition, our results expand the phenotype spectrum of LAMB2 mutations as the only renal manifestation.
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Affiliation(s)
- Liru Qiu
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science & Technology, Wuhan, 430030, China
| | - Jianhua Zhou
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science & Technology, Wuhan, 430030, China.
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23
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Bull KR, Mason T, Rimmer AJ, Crockford TL, Silver KL, Bouriez-Jones T, Hough TA, Chaudhry S, Roberts ISD, Goodnow CC, Cornall RJ. Next-generation sequencing to dissect hereditary nephrotic syndrome in mice identifies a hypomorphic mutation in Lamb2 and models Pierson's syndrome. J Pathol 2014; 233:18-26. [PMID: 24293254 PMCID: PMC4241031 DOI: 10.1002/path.4308] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Revised: 11/15/2013] [Accepted: 11/21/2013] [Indexed: 01/11/2023]
Abstract
The study of mutations causing the steroid-resistant nephrotic syndrome in children has greatly advanced our understanding of the kidney filtration barrier. In particular, these genetic variants have illuminated the roles of the podocyte, glomerular basement membrane and endothelial cell in glomerular filtration. However, in a significant number of familial and early onset cases, an underlying mutation cannot be identified, indicating that there are likely to be multiple unknown genes with roles in glomerular permeability. We now show how the combination of N-ethyl-N-nitrosourea mutagenesis and next-generation sequencing could be used to identify the range of mutations affecting these pathways. Using this approach, we isolated a novel mouse strain with a viable nephrotic phenotype and used whole-genome sequencing to isolate a causative hypomorphic mutation in Lamb2. This discovery generated a model for one part of the spectrum of human Pierson’s syndrome and provides a powerful proof of principle for accelerating gene discovery and improving our understanding of inherited forms of renal disease. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd
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Affiliation(s)
- Katherine R Bull
- Nuffield Department of Medicine and Wellcome Trust Centre for Human Genetics, Oxford University, UK
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Gnanaguru G, Bachay G, Biswas S, Pinzón-Duarte G, Hunter DD, Brunken WJ. Laminins containing the β2 and γ3 chains regulate astrocyte migration and angiogenesis in the retina. Development 2013; 140:2050-60. [PMID: 23571221 DOI: 10.1242/dev.087817] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Pathologies of retinal blood vessels are among the major causes of blindness worldwide. A key cell type that regulates retinal vascular development is the astrocyte. Generated extrinsically to the retina, astrocytes migrate into the retina through the optic nerve head. Even though there is a strong correlation between astrocyte distribution and retinal vascular development, the factors that guide astrocytes into the retina remain unclear. In this study, we show that astrocytes migrate within a laminin-containing basement membrane - the inner limiting membrane. Genetic deletion of the laminin β2 and γ3 chains affects astrocyte migration and spatial distribution. We show that laminins act as haptotactic factors in vitro in an isoform-specific manner, inducing astrocyte migration and promoting astrocyte differentiation. The addition of exogenous laminins to laminin-null retinal explants rescues astrocyte migration and spatial patterning. Furthermore, we show that the loss of laminins reduces β1 integrin expression in astrocytes. Culturing laminin-null retinal astrocytes on laminin substrates restores focal localization of β1 integrin. Finally, we show that laminins containing β2 and γ3 chains regulate subsequent retinal blood vessel growth and maintain vascular integrity. These in vivo and in vitro studies demonstrate clearly that laminins containing β2 and γ3 chains are indispensable for migration and spatial organization of astrocytes and that they play a crucial role during retinal angiogenesis in vivo.
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Affiliation(s)
- Gopalan Gnanaguru
- Departments of Ophthalmology and Cell Biology, and the SUNY Eye Institute, State University of New York, Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, New York 11203, USA
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Gnanaguru G, Brunken WJ. The cell-matrix interface: a possible target for treating retinal vascular related pathologies. J Ophthalmic Vis Res 2012; 7:316-27. [PMID: 23503323 PMCID: PMC3595586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2012] [Accepted: 09/02/2012] [Indexed: 12/02/2022] Open
Abstract
Retinal vasculature related pathologies account for a large proportion of global blindness. Choroidal neovascularization accompanying age-related macular degeneration is the largest cause of blindness in people over the age of 65 years, proliferative diabetic retinopathy is the main cause of acquired blindness in working adults, and retinopathy of prematurity (ROP) is the leading cause of acquired blindness in children. Given the great success in treating the first category of these conditions with anti-vascular endothelial growth factor (anti-VEGF) therapy, there is understandably considerable interest to employ this strategy to other retinal vascular disorders. Anti-VEGF therapy may not be the optimal course of action, as it may compromise neuronal survival; this is of particular concern when treating ROP where retinal neurogenesis is still not complete. Moreover, retinal neovascularization is preceded by alterations in the vascular wall extracellular matrix with concomitant reduction in mural cell adhesion. This produces vascular instability followed by the pathobiologic process of neovascularization. Thus, stabilizing mural cell-matrix interactions would be a prudent alternative for controlling retinal vascular pathologies. In this review, we will summarize the development of retinal angiogenesis focusing on the role of cell-matrix interaction in each step of the process. Our goal is to identify potential targets for regulating and maintaining normal vascular development and function.
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Affiliation(s)
| | - William J Brunken
- William J. Brunken, PhD. Professor and Director of Ophthalmic Research, Departments of Ophthalmology and of Cell Biology- Box 5, State University of New York- Downstate Medical Center, 450 Clarkson Ave, Brooklyn, NY 11203, USA; e-mail:
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Abstract
PURPOSE OF REVIEW Anterior segment dysgenesis (ASD) disorders encompass a spectrum of developmental conditions affecting the cornea, iris, and lens and are generally associated with an approximate 50% risk for glaucoma. These conditions are characterized by both autosomal dominant and recessive patterns of inheritance often with incomplete penetrance/variable expressivity. This article summarizes what is known about the genetics of ASD disorders and reviews recent developments. RECENT FINDINGS Mutations in Collagen type IV alpha-1 (COL4A1) and Beta-1,3-galactosyltransferase-like (B3GALTL) have been reported in ASD patients. Novel findings in other well known ocular genes are also presented, among which regulatory region deletions in PAX6 and PITX2 are most notable. SUMMARY Although a number of genetic causes have been identified, many ASD conditions are still awaiting genetic elucidation. The majority of characterized ASD genes encode transcription factors; several other genes represent extracellular matrix-related proteins. All of the involved genes play active roles in ocular development and demonstrate conserved functions across species. The use of novel technologies, such as whole genome sequencing/comparative genomic hybridization, is likely to broaden the mutation spectrums in known genes and assist in the identification of novel causative genes as well as modifiers explaining the phenotypic variability of ASD conditions.
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