1
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Stallworth JY, Blair DR, Slavotinek A, Moore AT, Duncan JL, de Alba Campomanes AG. Retinopathy and optic atrophy in a case of COQ2-related primary coenzyme Q 10 deficiency. Ophthalmic Genet 2023; 44:486-490. [PMID: 36420660 PMCID: PMC10205914 DOI: 10.1080/13816810.2022.2141792] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2022] [Revised: 09/08/2022] [Accepted: 10/22/2022] [Indexed: 11/25/2022]
Abstract
PURPOSE To describe a case of primary coenzyme Q10 deficiency in a child manifesting as early-onset renal failure, retinal dystrophy, and optic atrophy leading to progressive vision loss. METHODS Clinical presentation and workup including visual fields, electroretinogram, and optical coherence tomography are presented. Genetic testing was performed. RESULTS An eight-year-old female with nephropathy requiring renal transplantation subsequently developed progressive cone-rod dystrophy and optic atrophy. The patient had negative results on a targeted next-generation sequencing retinal dystrophy panel but whole-exome sequencing revealed two variants in COQ2 (likely biallelic), consistent with a diagnosis of primary coenzyme Q10 deficiency. CONCLUSIONS Primary coenzyme Q10 deficiency is a rare disorder with variable systemic and ocular findings; there is also genetic heterogeneity. Genetic testing aids in the diagnosis of this condition, and variants in the COQ2 and PDSS1 genes appear to have the strongest association with ocular manifestations. Oral supplementation of coenzyme Q10 may slow progression of disease. This case highlights the utility of whole-exome sequencing in the diagnosis of a rare syndromic form of ocular disease and reports a novel phenotypic association for this condition.
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Affiliation(s)
| | - David R Blair
- Department of Pediatrics, University of California, San Francisco, CA, USA
| | - Anne Slavotinek
- Department of Pediatrics, University of California, San Francisco, CA, USA
| | - Anthony T Moore
- Department of Ophthalmology, University of California, San Francisco, CA, USA
| | - Jacque L Duncan
- Department of Ophthalmology, University of California, San Francisco, CA, USA
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2
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Precise clinicopathologic findings for application of genetic testing in pediatric kidney transplant recipients with focal segmental glomerulosclerosis/steroid-resistant nephrotic syndrome. Pediatr Nephrol 2023; 38:417-429. [PMID: 35655039 DOI: 10.1007/s00467-022-05604-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 04/29/2022] [Accepted: 04/29/2022] [Indexed: 01/10/2023]
Abstract
BACKGROUND Establishing a molecular genetic diagnosis of focal segmental glomerulosclerosis (FSGS)/steroid-resistant nephrotic syndrome (SRNS) can be useful for predicting post-transplant recurrence. Monogenic causes are reportedly present in approximately 20-30% of patients with FSGS/SRNS. However, the characteristics of patients who are likely to have a monogenic cause remain to be determined. METHODS Pediatric recipients with SRNS and/or biopsy-proven FSGS who underwent their first kidney transplantation at our center between 1999 and 2019 were analyzed. Patients with secondary FSGS/SRNS were excluded. The recipients were divided into three groups: familial/syndromic, presumed primary, and undetermined FSGS/SRNS. Patients who met all of the following criteria were categorized as having presumed primary FSGS/SRNS: (i) nephrotic syndrome, (ii) complete or partial remission with initial steroid therapy and/or additional immunosuppressive therapies, and (iii) diffuse foot process effacement on electron microscopy in the native kidney biopsy. All patients underwent genetic testing using next-generation sequencing. RESULTS Twenty-four patients from 23 families were analyzed in this study. Pathogenic or likely pathogenic variants in FSGS/SRNS-related genes were identified in four of four families, zero of eight families, and 10 of 11 families with familial/syndromic, presumed primary, and undetermined FSGS/SRNS, respectively. Post-transplant recurrence only occurred in patients with presumed primary FSGS/SRNS. CONCLUSIONS Our systematic approach based on precise clinicopathological findings including nephrotic syndrome, treatment responses, and diffuse foot process effacement might be useful to differentiate pediatric kidney transplant recipients with FSGS/SRNS who are likely to have a monogenic cause from patients who are not, and to predict post-transplant recurrence. A higher resolution version of the Graphical abstract is available as Supplementary information.
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3
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Bierzynska A, Bull K, Miellet S, Dean P, Neal C, Colby E, McCarthy HJ, Hegde S, Sinha MD, Bugarin Diz C, Stirrups K, Megy K, Mapeta R, Penkett C, Marsh S, Forrester N, Afzal M, Stark H, BioResource NIHR, Williams M, Welsh GI, Koziell AB, Hartley PS, Saleem MA. Exploring the relevance of NUP93 variants in steroid-resistant nephrotic syndrome using next generation sequencing and a fly kidney model. Pediatr Nephrol 2022; 37:2643-2656. [PMID: 35211795 PMCID: PMC9489583 DOI: 10.1007/s00467-022-05440-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 12/10/2021] [Accepted: 12/21/2021] [Indexed: 10/24/2022]
Abstract
BACKGROUND Variants in genes encoding nuclear pore complex (NPC) proteins are a newly identified cause of paediatric steroid-resistant nephrotic syndrome (SRNS). Recent reports describing NUP93 variants suggest these could be a significant cause of paediatric onset SRNS. We report NUP93 cases in the UK and demonstrate in vivo functional effects of Nup93 depletion in a fly (Drosophila melanogaster) nephrocyte model. METHODS Three hundred thirty-seven paediatric SRNS patients from the National cohort of patients with Nephrotic Syndrome (NephroS) were whole exome and/or whole genome sequenced. Patients were screened for over 70 genes known to be associated with Nephrotic Syndrome (NS). D. melanogaster Nup93 knockdown was achieved by RNA interference using nephrocyte-restricted drivers. RESULTS Six novel homozygous and compound heterozygous NUP93 variants were detected in 3 sporadic and 2 familial paediatric onset SRNS characterised histologically by focal segmental glomerulosclerosis (FSGS) and progressing to kidney failure by 12 months from clinical diagnosis. Silencing of the two orthologs of human NUP93 expressed in D. melanogaster, Nup93-1, and Nup93-2 resulted in significant signal reduction of up to 82% in adult pericardial nephrocytes with concomitant disruption of NPC protein expression. Additionally, nephrocyte morphology was highly abnormal in Nup93-1 and Nup93-2 silenced flies surviving to adulthood. CONCLUSION We expand the spectrum of NUP93 variants detected in paediatric onset SRNS and demonstrate its incidence within a national cohort. Silencing of either D. melanogaster Nup93 ortholog caused a severe nephrocyte phenotype, signaling an important role for the nucleoporin complex in podocyte biology. A higher resolution version of the Graphical abstract is available as Supplementary information.
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Affiliation(s)
- Agnieszka Bierzynska
- Bristol Renal and Children’s Renal Unit, Bristol Medical School, University of Bristol, Whitson Street, Bristol, BS1 3NY UK
| | - Katherine Bull
- Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Sara Miellet
- Department of Life and Environmental Science, Bournemouth University, Talbot Campus, Fern Barrow, Poole, Dorset BH12 5BB England, UK
- Illawarra Health and Medical Research Institute, Molecular Horizons and School of Medicine, University of Wollongong, Wollongong, Australia
| | - Philip Dean
- Bristol Genetics Laboratory, North Bristol National Health Service Trust, Bristol, UK
| | - Chris Neal
- Bristol Renal and Children’s Renal Unit, Bristol Medical School, University of Bristol, Whitson Street, Bristol, BS1 3NY UK
| | - Elizabeth Colby
- Bristol Renal and Children’s Renal Unit, Bristol Medical School, University of Bristol, Whitson Street, Bristol, BS1 3NY UK
| | - Hugh J. McCarthy
- Bristol Renal and Children’s Renal Unit, Bristol Medical School, University of Bristol, Whitson Street, Bristol, BS1 3NY UK
- School of Medicine, University of Sydney and Children’s Hospital at Westmead, Westmead, Australia
| | - Shivaram Hegde
- Children’s Kidney Centre, University Hospital of Wales, Cardiff, UK
| | - Manish D. Sinha
- Department of Paediatric Nephrology, Evelina London Children’s Hospital, Guy’s and St, Thomas’ Hospital, London, UK
| | - Carmen Bugarin Diz
- School of Immunology and Microbial Sciences, Faculty of Life Sciences and Medicine, King’s College London, London, SE1 7EH UK
| | - Kathleen Stirrups
- NIHR BioResource, Cambridge University Hospitals, Cambridge Biomedical Campus, Cambridge, CB2 0QQ UK
| | - Karyn Megy
- NIHR BioResource, Cambridge University Hospitals, Cambridge Biomedical Campus, Cambridge, CB2 0QQ UK
- Centre for Genomics Research, Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Rutendo Mapeta
- NIHR BioResource, Cambridge University Hospitals, Cambridge Biomedical Campus, Cambridge, CB2 0QQ UK
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, CB10 1SA UK
| | - Chris Penkett
- NIHR BioResource, Cambridge University Hospitals, Cambridge Biomedical Campus, Cambridge, CB2 0QQ UK
| | - Sarah Marsh
- Bristol Genetics Laboratory, North Bristol National Health Service Trust, Bristol, UK
| | - Natalie Forrester
- Illawarra Health and Medical Research Institute, Molecular Horizons and School of Medicine, University of Wollongong, Wollongong, Australia
| | - Maryam Afzal
- Bristol Renal and Children’s Renal Unit, Bristol Medical School, University of Bristol, Whitson Street, Bristol, BS1 3NY UK
| | - Hannah Stark
- NIHR BioResource, Cambridge University Hospitals, Cambridge Biomedical Campus, Cambridge, CB2 0QQ UK
| | - NIHR BioResource
- NIHR BioResource, Cambridge University Hospitals, Cambridge Biomedical Campus, Cambridge, CB2 0QQ UK
| | - Maggie Williams
- Bristol Genetics Laboratory, North Bristol National Health Service Trust, Bristol, UK
| | - Gavin I. Welsh
- Bristol Renal and Children’s Renal Unit, Bristol Medical School, University of Bristol, Whitson Street, Bristol, BS1 3NY UK
| | - Ania B. Koziell
- Department of Paediatric Nephrology, Evelina London Children’s Hospital, Guy’s and St, Thomas’ Hospital, London, UK
- School of Immunology and Microbial Sciences, Faculty of Life Sciences and Medicine, King’s College London, London, SE1 7EH UK
| | - Paul S. Hartley
- Department of Life and Environmental Science, Bournemouth University, Talbot Campus, Fern Barrow, Poole, Dorset BH12 5BB England, UK
| | - Moin A. Saleem
- Bristol Renal and Children’s Renal Unit, Bristol Medical School, University of Bristol, Whitson Street, Bristol, BS1 3NY UK
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4
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Jurkute N, Cancellieri F, Pohl L, Li CHZ, Heaton RA, Reurink J, Bellingham J, Quinodoz M, Yioti G, Stefaniotou M, Weener M, Zuleger T, Haack TB, Stingl K, Hoyng CB, Mahroo OA, Hargreaves I, Raymond FL, Michaelides M, Rivolta C, Kohl S, Roosing S, Webster AR, Arno G. Biallelic variants in coenzyme Q10 biosynthesis pathway genes cause a retinitis pigmentosa phenotype. NPJ Genom Med 2022; 7:60. [PMID: 36266294 PMCID: PMC9581764 DOI: 10.1038/s41525-022-00330-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 09/29/2022] [Indexed: 11/21/2022] Open
Abstract
The aim of this study was to investigate coenzyme Q10 (CoQ10) biosynthesis pathway defects in inherited retinal dystrophy. Individuals affected by inherited retinal dystrophy (IRD) underwent exome or genome sequencing for molecular diagnosis of their condition. Following negative IRD gene panel analysis, patients carrying biallelic variants in CoQ10 biosynthesis pathway genes were identified. Clinical data were collected from the medical records. Haplotypes harbouring the same missense variant were characterised from family genome sequencing (GS) data and direct Sanger sequencing. Candidate splice variants were characterised using Oxford Nanopore Technologies single molecule sequencing. The CoQ10 status of the human plasma was determined in some of the study patients. 13 individuals from 12 unrelated families harboured candidate pathogenic genotypes in the genes: PDSS1, COQ2, COQ4 and COQ5. The PDSS1 variant c.589 A > G was identified in three affected individuals from three unrelated families on a possible ancestral haplotype. Three variants (PDSS1 c.468-25 A > G, PDSS1 c.722-2 A > G, COQ5 c.682-7 T > G) were shown to lead to cryptic splicing. 6 affected individuals were diagnosed with non-syndromic retinitis pigmentosa and 7 had additional clinical findings. This study provides evidence of CoQ10 biosynthesis pathway gene defects leading to non-syndromic retinitis pigmentosa in some cases. Intronic variants outside of the canonical splice-sites represent an important cause of disease. RT-PCR nanopore sequencing is effective in characterising these splice defects.
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Affiliation(s)
- Neringa Jurkute
- Moorfields Eye Hospital NHS Foundation Trust, London, UK. .,Institute of Ophthalmology, University College London, London, UK.
| | - Francesca Cancellieri
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), Basel, Switzerland.,Department of Ophthalmology, University of Basel, Basel, Switzerland
| | - Lisa Pohl
- University Eye Hospital, Centre for Ophthalmology, University Hospital Tübingen, Tübingen, Germany
| | - Catherina H Z Li
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands.,Department of Ophthalmology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Robert A Heaton
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores, Liverpool, UK
| | - Janine Reurink
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands.,Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - James Bellingham
- Institute of Ophthalmology, University College London, London, UK
| | - Mathieu Quinodoz
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), Basel, Switzerland.,Department of Ophthalmology, University of Basel, Basel, Switzerland.,Department of Genetics and Genome Biology, University of Leicester, Leicester, UK
| | - Georgia Yioti
- University of Ioannina Medical School, Ioannina, Greece
| | | | | | - Theresia Zuleger
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Tobias B Haack
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany.,Centre for Rare Diseases, University of Tübingen, Tübingen, Germany
| | - Katarina Stingl
- University Eye Hospital, Centre for Ophthalmology, University Hospital Tübingen, Tübingen, Germany.,Centre for Rare Diseases, University of Tübingen, Tübingen, Germany
| | | | - Carel B Hoyng
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands.,Department of Ophthalmology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Omar A Mahroo
- Moorfields Eye Hospital NHS Foundation Trust, London, UK.,Institute of Ophthalmology, University College London, London, UK
| | - Iain Hargreaves
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores, Liverpool, UK
| | - F Lucy Raymond
- NIHR BioResource-Rare Diseases, Cambridge University Hospitals NHS Foundation Trust, Cambridge Biomedical Campus, Cambridge, UK.,Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK
| | - Michel Michaelides
- Moorfields Eye Hospital NHS Foundation Trust, London, UK.,Institute of Ophthalmology, University College London, London, UK
| | - Carlo Rivolta
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), Basel, Switzerland.,Department of Ophthalmology, University of Basel, Basel, Switzerland.,Department of Genetics and Genome Biology, University of Leicester, Leicester, UK
| | - Susanne Kohl
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Susanne Roosing
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands.,Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Andrew R Webster
- Moorfields Eye Hospital NHS Foundation Trust, London, UK.,Institute of Ophthalmology, University College London, London, UK
| | - Gavin Arno
- Moorfields Eye Hospital NHS Foundation Trust, London, UK. .,Institute of Ophthalmology, University College London, London, UK. .,North Thames Genomic Laboratory Hub, Great Ormond Street Hospital for Children, London, UK.
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5
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Claus LR, Snoek R, Knoers NVAM, van Eerde AM. Review of genetic testing in kidney disease patients: Diagnostic yield of single nucleotide variants and copy number variations evaluated across and within kidney phenotype groups. AMERICAN JOURNAL OF MEDICAL GENETICS. PART C, SEMINARS IN MEDICAL GENETICS 2022; 190:358-376. [PMID: 36161467 PMCID: PMC9828643 DOI: 10.1002/ajmg.c.31995] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 07/02/2022] [Accepted: 08/18/2022] [Indexed: 01/29/2023]
Abstract
Genetic kidney disease comprises a diverse group of disorders. These can roughly be divided in the phenotype groups congenital anomalies of the kidney and urinary tract, ciliopathies, glomerulopathies, stone disorders, tubulointerstitial kidney disease, and tubulopathies. Many etiologies can lead to chronic kidney disease that can progress to end-stage kidney disease. Despite each individual disease being rare, together these genetic disorders account for a large proportion of kidney disease cases. With the introduction of massively parallel sequencing, genetic testing has become more accessible, but a comprehensive analysis of the diagnostic yield is lacking. This review gives an overview of the diagnostic yield of genetic testing across and within the full range of kidney disease phenotypes through a systematic literature search that resulted in 115 included articles. Patient, test, and cohort characteristics that can influence the diagnostic yield are highlighted. Detection of copy number variations and their contribution to the diagnostic yield is described for all phenotype groups. Also, the impact of a genetic diagnosis for a patient and family members, which can be diagnostic, therapeutic, and prognostic, is shown through the included articles. This review will allow clinicians to estimate an a priori probability of finding a genetic cause for the kidney disease in their patients.
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Affiliation(s)
- Laura R. Claus
- Department of GeneticsUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Rozemarijn Snoek
- Department of GeneticsUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Nine V. A. M. Knoers
- Department of GeneticsUniversity Medical Center GroningenGroningenThe Netherlands
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6
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Zidoune H, Ladjouze A, Chellat-Rezgoune D, Boukri A, Dib SA, Nouri N, Tebibel M, Sifi K, Abadi N, Satta D, Benelmadani Y, Bignon-Topalovic J, El-Zaiat-Munsch M, Bashamboo A, McElreavey K. Novel Genomic Variants, Atypical Phenotypes and Evidence of a Digenic/Oligogenic Contribution to Disorders/Differences of Sex Development in a Large North African Cohort. Front Genet 2022; 13:900574. [PMID: 36110220 PMCID: PMC9468775 DOI: 10.3389/fgene.2022.900574] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Accepted: 05/23/2022] [Indexed: 11/13/2022] Open
Abstract
In a majority of individuals with disorders/differences of sex development (DSD) a genetic etiology is often elusive. However, new genes causing DSD are routinely reported and using the unbiased genomic approaches, such as whole exome sequencing (WES) should result in an increased diagnostic yield. Here, we performed WES on a large cohort of 125 individuals all of Algerian origin, who presented with a wide range of DSD phenotypes. The study excluded individuals with congenital adrenal hypoplasia (CAH) or chromosomal DSD. Parental consanguinity was reported in 36% of individuals. The genetic etiology was established in 49.6% (62/125) individuals of the total cohort, which includes 42.2% (35/83) of 46, XY non-syndromic DSD and 69.2% (27/39) of 46, XY syndromic DSD. No pathogenic variants were identified in the 46, XX DSD cases (0/3). Variants in the AR, HSD17B3, NR5A1 and SRD5A2 genes were the most common causes of DSD. Other variants were identified in genes associated with congenital hypogonadotropic hypogonadism (CHH), including the CHD7 and PROKR2. Previously unreported pathogenic/likely pathogenic variants (n = 30) involving 25 different genes were identified in 22.4% of the cohort. Remarkably 11.5% of the 46, XY DSD group carried variants classified as pathogenic/likely pathogenic variant in more than one gene known to cause DSD. The data indicates that variants in PLXNA3, a candidate CHH gene, is unlikely to be involved in CHH. The data also suggest that NR2F2 variants may cause 46, XY DSD.
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Affiliation(s)
- Housna Zidoune
- Human Developmental Genetics Unit, Institut Pasteur, CNRS, Paris, France
- Laboratory of Molecular and Cellular Biology, Department of Animal Biology, University Frères Mentouri Constantine 1, Constantine, Algeria
- Department of Medicine, Laboratory of Biology and Molecular Genetics, University Salah Boubnider Constantine 3, Constantine, Algeria
| | | | - Djalila Chellat-Rezgoune
- Laboratory of Molecular and Cellular Biology, Department of Animal Biology, University Frères Mentouri Constantine 1, Constantine, Algeria
- Department of Medicine, Laboratory of Biology and Molecular Genetics, University Salah Boubnider Constantine 3, Constantine, Algeria
| | - Asma Boukri
- Department of Endocrinology and Diabetology, CHU Ibn Badis Constantine, Constantine, Algeria
| | | | - Nassim Nouri
- Department of Endocrinology and Diabetology, CHU Ibn Badis Constantine, Constantine, Algeria
| | - Meryem Tebibel
- Department of Pediatric Surgery, CHU Beni Messous, Algiers, Algeria
| | - Karima Sifi
- Department of Medicine, Laboratory of Biology and Molecular Genetics, University Salah Boubnider Constantine 3, Constantine, Algeria
| | - Noureddine Abadi
- Department of Medicine, Laboratory of Biology and Molecular Genetics, University Salah Boubnider Constantine 3, Constantine, Algeria
| | - Dalila Satta
- Laboratory of Molecular and Cellular Biology, Department of Animal Biology, University Frères Mentouri Constantine 1, Constantine, Algeria
- Department of Medicine, Laboratory of Biology and Molecular Genetics, University Salah Boubnider Constantine 3, Constantine, Algeria
| | - Yasmina Benelmadani
- Department of Medicine, Laboratory of Biology and Molecular Genetics, University Salah Boubnider Constantine 3, Constantine, Algeria
| | | | | | - Anu Bashamboo
- Human Developmental Genetics Unit, Institut Pasteur, CNRS, Paris, France
| | - Ken McElreavey
- Human Developmental Genetics Unit, Institut Pasteur, CNRS, Paris, France
- *Correspondence: Ken McElreavey,
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7
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Jankowski M, Daca-Roszak P, Obracht-Prondzyński C, Płoski R, Lipska-Ziętkiewicz BS, Ziętkiewicz E. Genetic diversity in Kashubs: the regional increase in the frequency of several disease-causing variants. J Appl Genet 2022; 63:691-701. [PMID: 35971028 PMCID: PMC9637066 DOI: 10.1007/s13353-022-00713-z] [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: 03/22/2022] [Revised: 07/12/2022] [Accepted: 07/18/2022] [Indexed: 12/02/2022]
Abstract
Differential distribution of genetic variants’ frequency among human populations is caused by the genetic drift in isolated populations, historical migrations, and demography. Some of these variants are identical by descent and represent founder mutations, which — if pathogenic in nature — lead to the increased frequency of otherwise rare diseases. The detection of the increased regional prevalence of pathogenic variants may shed light on the historical processes that affected studied populations and can help to develop effective screening and diagnostic strategies as a part of personalized medicine. Here, we discuss the specific genetic diversity in Kashubs, the minority group living in northern Poland, reflected in the biased distribution of some of the repetitively found disease-causing variants. These include the following: (1) c.662A > G (p.Asp221Gly) in LDLR, causing heterozygous familial hypercholesterolemia; (2) c.3700_3704del in BRCA1, associated with hereditary breast and ovarian cancer syndrome; (3) c.1528G > C (p.Glu510Gln) in HADHA, seen in long-chain 3-hydroxy acyl-CoA dehydrogenase (LCHAD) deficiency, and (4) c.1032delT in NPHS2, associated with steroid-resistant nephrotic syndrome.
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Affiliation(s)
- Maciej Jankowski
- Department of Biology and Medical Genetics, Medical University of Gdansk, Gdansk, Poland
| | | | | | - Rafał Płoski
- Department of Medical Genetics, Medical University of Warsaw, Warsaw, Poland
| | - Beata S Lipska-Ziętkiewicz
- Clinical Genetics Unit, Department of Biology and Medical Genetics, Medical University of Gdansk, Gdansk, Poland. .,Centre for Rare Diseases, Medical University of Gdansk, Gdansk, Poland.
| | - Ewa Ziętkiewicz
- Institute of Human Genetics, Polish Academy of Sciences, Poznan, Poland.
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8
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Identification of Nephrin gene variants in Indian children associated with Steroid sensitive and Steroid resistant nephrotic syndrome. Meta Gene 2022. [DOI: 10.1016/j.mgene.2021.101004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
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9
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da Silva Filha R, Burini K, Pires LG, Brant Pinheiro SV, Simões E Silva AC. Idiopathic Nephrotic Syndrome in Pediatrics: An Up-to-date. Curr Pediatr Rev 2022; 18:251-264. [PMID: 35289253 DOI: 10.2174/1573396318666220314142713] [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] [Received: 09/13/2021] [Revised: 10/31/2021] [Accepted: 12/12/2021] [Indexed: 11/22/2022]
Abstract
BACKGROUND Idiopathic or Primary Nephrotic Syndrome (INS) is a common glomerular disease in pediatric population, characterized by proteinuria, edema and hypoalbuminemia with variable findings in renal histopathology. OBJECTIVE This review aims to summarize current data on the etiopathogenesis diagnosis, protocols of treatment and potential therapeutic advances in INS. METHODS This narrative review searched for articles on histopathology, physiopathology, genetic causes, diagnosis and treatment of INS in pediatric patients. The databases evaluated were PubMed and Scopus. RESULTS INS is caused by an alteration in the permeability of the glomerular filtration barrier with unknown etiology. There are several gaps in the etiopathogenesis, response to treatment and clinical course of INS that justify further investigation. Novel advances include the recent understanding of the role of podocytes in INS and the identification of genes associated with the disease. The role of immune system cells and molecules has also been investigated. The diagnosis relies on clinical findings, laboratory exams and renal histology for selected cases. The treatment is primarily based on steroids administration. In case of failure, other medications should be tried. Recent studies have also searched for novel biomarkers for diagnosis and alternative therapeutic approaches. CONCLUSION The therapeutic response to corticosteroids still remains the main predictive factor for the prognosis of the disease. Genetic and pharmacogenomics tools may allow the identification of cases not responsive to immunosuppressive medications.
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Affiliation(s)
- Roberta da Silva Filha
- Faculty of Medicine, Interdisciplinary Laboratory of Medical Investigation, Federal University of Minas Gerais (UFMG), Belo Horizonte, MG, Brazil
| | - Kassia Burini
- Faculty of Medicine, Interdisciplinary Laboratory of Medical Investigation, Federal University of Minas Gerais (UFMG), Belo Horizonte, MG, Brazil
| | - Laura Gregório Pires
- Faculty of Medicine, Interdisciplinary Laboratory of Medical Investigation, Federal University of Minas Gerais (UFMG), Belo Horizonte, MG, Brazil
| | | | - Ana Cristina Simões E Silva
- Faculty of Medicine, Interdisciplinary Laboratory of Medical Investigation, Federal University of Minas Gerais (UFMG), Belo Horizonte, MG, Brazil.,Department of Pediatrics, Unit of Pediatric Nephrology, Faculty of Medicine, UFMG, Belo Horizonte, MG, Brazil
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10
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Primary coenzyme Q10 nephropathy, a potentially treatable form of steroid-resistant nephrotic syndrome. Pediatr Nephrol 2021; 36:3515-3527. [PMID: 33479824 PMCID: PMC8295399 DOI: 10.1007/s00467-020-04914-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 11/28/2020] [Accepted: 12/31/2020] [Indexed: 12/18/2022]
Abstract
Steroid-resistant nephrotic syndrome (SRNS) is a genetically heterogeneous kidney disease that is the second most frequent cause of kidney failure in the first 2 decades of life. Despite the identification of mutations in more than 39 genes as causing SRNS, and the localization of its pathogenesis to glomerular podocytes, the disease mechanisms of SRNS remain poorly understood and no universally safe and effective therapy exists to treat patients with this condition. Recently, genetic research has identified a subgroup of SRNS patients whose kidney pathology is caused by primary coenzyme Q10 (CoQ10) deficiency due to recessive mutations in genes that encode proteins in the CoQ10 biosynthesis pathway. Clinical and preclinical studies show that primary CoQ10 deficiency may be responsive to treatment with CoQ10 supplements bypassing the biosynthesis defects. Coenzyme Q10 is an essential component of the mitochondrial respiratory chain, where it transports electrons from complexes I and II to complex III. Studies in yeast and mammalian model systems have recently identified the molecular functions of the individual CoQ10 biosynthesis complex proteins, validated these findings, and provided an impetus for developing therapeutic compounds to replenish CoQ10 levels in the tissues/organs and thus prevent the destruction of tissues due to mitochondrial OXPHOS deficiencies. In this review, we will summarize the clinical findings of the kidney pathophysiology of primary CoQ10 deficiencies and discuss recent advances in the development of therapies to counter CoQ10 deficiency in tissues.
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11
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Tanoue A, Katayama K, Ito Y, Joh K, Toda M, Yasuma T, D'Alessandro-Gabazza CN, Kawachi H, Yan K, Ito M, Gabazza EC, Tryggvason K, Dohi K. Podocyte-specific Crb2 knockout mice develop focal segmental glomerulosclerosis. Sci Rep 2021; 11:20556. [PMID: 34654837 PMCID: PMC8519956 DOI: 10.1038/s41598-021-00159-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 10/07/2021] [Indexed: 11/15/2022] Open
Abstract
Crb2 is a cell polarity-related type I transmembrane protein expressed in the apical membrane of podocytes. Knockdown of crb2 causes glomerular permeability defects in zebrafish, and its complete knockout causes embryonic lethality in mice. There are also reports of Crb2 mutations in patients with steroid-resistant nephrotic syndrome, although the precise mechanism is unclear. The present study demonstrated that podocyte-specific Crb2 knockout mice develop massive albuminuria and microhematuria 2-month after birth and focal segmental glomerulosclerosis and tubulointerstitial fibrosis with hemosiderin-laden macrophages at 6-month of age. Transmission and scanning electron microscopic studies demonstrated injury and foot process effacement of podocytes in 6-month aged podocyte-specific Crb2 knockout mice. The number of glomerular Wt1-positive cells and the expressions of Nphs2, Podxl, and Nphs1 were reduced in podocyte-specific Crb2 knockout mice compared to negative control mice. Human podocytes lacking CRB2 had significantly decreased F-actin positive area and were more susceptible to apoptosis than their wild-type counterparts. Overall, this study's results suggest that the specific deprivation of Crb2 in podocytes induces altered actin cytoskeleton reorganization associated with dysfunction and accelerated apoptosis of podocytes that ultimately cause focal segmental glomerulosclerosis.
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Affiliation(s)
- Akiko Tanoue
- Department of Cardiology and Nephrology, Mie University Graduate School of Medicine, 2-174 Edobashi, Tsu, Mie, 514-8507, Japan
| | - Kan Katayama
- Department of Cardiology and Nephrology, Mie University Graduate School of Medicine, 2-174 Edobashi, Tsu, Mie, 514-8507, Japan.
- Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden.
| | - Yugo Ito
- Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden
- Department of Pediatrics, Kyorin University School of Medicine, Tokyo, Japan
| | - Kensuke Joh
- Department of Pathology, The Jikei University School of Medicine, Tokyo, Japan
| | - Masaaki Toda
- Department of Immunology, Mie University Graduate School of Medicine, Mie, Japan
| | - Taro Yasuma
- Department of Immunology, Mie University Graduate School of Medicine, Mie, Japan
| | | | - Hiroshi Kawachi
- Department of Cell Biology, Kidney Research Center, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Kunimasa Yan
- Department of Pediatrics, Kyorin University School of Medicine, Tokyo, Japan
| | - Masaaki Ito
- Department of Cardiology and Nephrology, Mie University Graduate School of Medicine, 2-174 Edobashi, Tsu, Mie, 514-8507, Japan
| | - Esteban C Gabazza
- Department of Immunology, Mie University Graduate School of Medicine, Mie, Japan
| | - Karl Tryggvason
- Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden
- Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, Singapore, Singapore
| | - Kaoru Dohi
- Department of Cardiology and Nephrology, Mie University Graduate School of Medicine, 2-174 Edobashi, Tsu, Mie, 514-8507, Japan
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Thakor JM, Parmar G, Mistry KN, Gang S, Rank DN, Joshi CG. Mutational landscape of TRPC6, WT1, LMX1B, APOL1, PTPRO, PMM2, LAMB2 and WT1 genes associated with Steroid resistant nephrotic syndrome. Mol Biol Rep 2021; 48:7193-7201. [PMID: 34546508 DOI: 10.1007/s11033-021-06711-4] [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: 07/24/2021] [Accepted: 09/14/2021] [Indexed: 10/20/2022]
Abstract
BACKGROUND Nephrotic syndrome appears as a group of symptoms like proteinuria, edema and hyperlipidemia. Identification of monogenic forms revealed the physiology and pathogenesis of the SRNS. METHODS AND RESULTS We performed Illumina panel sequencing of seven genes in 90 Indian patients to determine the role of these genetic mutations in nephrotic syndrome prognosis. Samtool was used for variants calling, and SnpEff and Snpsift did variants annotation. Clinical significance and variant classification were performed by the ClinVar database. In SSNS and SRNS patients, we found 0.78% pathogenic and 3.41% likely pathogenic mutations. Pathogenic mutations were found in LAMB2, LMX1B and WT1 genes, while likely pathogenic mutations were found in (6/13) LAMB2, (2/13) LMX1B, (2/13) TRPC6, (2/13) PTPRO and (1/13) PMM2 genes. Approximately 46% likely pathogenic mutations were contributed to the LAMB2 gene in SSNS and SRNS patients. We also detect 30 VUS (variants of uncertain significance), which were found (17/30) pathogenic and (13/30) likely pathogenic by different prediction tools. CONCLUSIONS Multigene panels were used for genetic screening of heterogeneous disorders like nephrotic syndrome in the Indian population. We found pathogenic, likely pathogenic and certain VUS, which were responsible for the pathogenesis of the disease. Therefore, mutational analysis of SSNS and SRNS is necessary to avoid adverse effects of corticosteroids, modify the intensity of immunosuppressing agents, and prevent the disease's progression.
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Affiliation(s)
- Jinal M Thakor
- Ashok and Rita Patel Institute of Integrated Study and Research in Biotechnology and Allied Sciences, ADIT Campus, New Vallabh Vidyanagar, 388121, Anand, Gujarat, India
| | - Glory Parmar
- Ashok and Rita Patel Institute of Integrated Study and Research in Biotechnology and Allied Sciences, ADIT Campus, New Vallabh Vidyanagar, 388121, Anand, Gujarat, India
| | - Kinnari N Mistry
- Ashok and Rita Patel Institute of Integrated Study and Research in Biotechnology and Allied Sciences, ADIT Campus, New Vallabh Vidyanagar, 388121, Anand, Gujarat, India.
| | - Sishir Gang
- Muljibhai Patel Urological Hospital, Dr. V.V. Desai Road, Nadiad, 387001, Gujarat, India
| | - Dharamshibhai N Rank
- Department of Animal Breeding and Genetics, College of Veterinary Sciences and Animal Husbandry, Anand Agricultural University, Anand, 388110, Gujarat, India
| | - Chaitanya G Joshi
- Department of Animal Biotechnology, College of Veterinary Sciences and Animal Husbandry, Anand Agricultural University, Anand, 388110, Gujarat, India
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13
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Cellular Models for Primary CoQ Deficiency Pathogenesis Study. Int J Mol Sci 2021; 22:ijms221910211. [PMID: 34638552 PMCID: PMC8508219 DOI: 10.3390/ijms221910211] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 09/17/2021] [Accepted: 09/18/2021] [Indexed: 02/07/2023] Open
Abstract
Primary coenzyme Q10 (CoQ) deficiency includes a heterogeneous group of mitochondrial diseases characterized by low mitochondrial levels of CoQ due to decreased endogenous biosynthesis rate. These diseases respond to CoQ treatment mainly at the early stages of the disease. The advances in the next generation sequencing (NGS) as whole-exome sequencing (WES) and whole-genome sequencing (WGS) have increased the discoveries of mutations in either gene already described to participate in CoQ biosynthesis or new genes also involved in this pathway. However, these technologies usually provide many mutations in genes whose pathogenic effect must be validated. To functionally validate the impact of gene variations in the disease’s onset and progression, different cell models are commonly used. We review here the use of yeast strains for functional complementation of human genes, dermal skin fibroblasts from patients as an excellent tool to demonstrate the biochemical and genetic mechanisms of these diseases and the development of human-induced pluripotent stem cells (hiPSCs) and iPSC-derived organoids for the study of the pathogenesis and treatment approaches.
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14
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Alcázar-Fabra M, Rodríguez-Sánchez F, Trevisson E, Brea-Calvo G. Primary Coenzyme Q deficiencies: A literature review and online platform of clinical features to uncover genotype-phenotype correlations. Free Radic Biol Med 2021; 167:141-180. [PMID: 33677064 DOI: 10.1016/j.freeradbiomed.2021.02.046] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 02/13/2021] [Accepted: 02/26/2021] [Indexed: 12/13/2022]
Abstract
Primary Coenzyme Q (CoQ) deficiencies are clinically heterogeneous conditions and lack clear genotype-phenotype correlations, complicating diagnosis and prognostic assessment. Here we present a compilation of all the symptoms and patients with primary CoQ deficiency described in the literature so far and analyse the most common clinical manifestations associated with pathogenic variants identified in the different COQ genes. In addition, we identified new associations between the age of onset of symptoms and different pathogenic variants, which could help to a better diagnosis and guided treatment. To make these results useable for clinicians, we created an online platform (https://coenzymeQbiology.github.io/clinic-CoQ-deficiency) about clinical manifestations of primary CoQ deficiency that will be periodically updated to incorporate new information published in the literature. Since CoQ primary deficiency is a rare disease, the available data are still limited, but as new patients are added over time, this tool could become a key resource for a more efficient diagnosis of this pathology.
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Affiliation(s)
- María Alcázar-Fabra
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-CSIC-JA and CIBERER, Instituto de Salud Carlos III, Seville, 41013, Spain
| | | | - Eva Trevisson
- Clinical Genetics Unit, Department of Women's and Children's Health, University of Padova, Padova, 35128, Italy; Istituto di Ricerca Pediatrica, Fondazione Città della Speranza, Padova, 35128, Italy.
| | - Gloria Brea-Calvo
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-CSIC-JA and CIBERER, Instituto de Salud Carlos III, Seville, 41013, Spain.
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15
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Next-generation sequencing in patients with familial FSGS: first report of collagen gene mutations in Tunisian patients. J Hum Genet 2021; 66:795-803. [PMID: 33654185 DOI: 10.1038/s10038-021-00912-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 01/09/2021] [Accepted: 02/16/2021] [Indexed: 11/08/2022]
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. FSGS is considered as a podocyte disease due to the fact that in the majority of patients with FSGS, the lesion results from defects in the podocyte structure. However, FSGS does not result exclusively from podocyte-associated genes. In this study, we used a genetic approach based on targeted next-generation sequencing (NGS) of 242 genes to identify the genetic cause of FSGS in seven Tunisian families. The sequencing results revealed the presence of eight distinct mutations including seven newly discovered ones: the c.538G>A (p.V180M) in NPHS2, c.5186G>A (p.R1729Q) in PLCE1 and c.232A>C (p.I78L) in PAX2 and five novel mutations in COL4A3 and COL4A4 genes. Four mutations (c.209G>A (p.G70D), c.725G>A (p.G242E), c.2225G>A (p.G742E), and c. 1681_1698del) were detected in COL4A3 gene and one mutation (c.1424G>A (p.G475D)) was found in COL4A4. In summary, NGS of a targeted gene panel is an ideal approach for the genetic testing of FSGS with multiple possible underlying etiologies. We have demonstrated that not only podocyte genes but also COL4A3/4 mutations should be considered in patients with FSGS.
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16
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Boyer O, Schaefer F, Haffner D, Bockenhauer D, Hölttä T, Bérody S, Webb H, Heselden M, Lipska-Zie˛tkiewicz BS, Ozaltin F, Levtchenko E, Vivarelli M. Management of congenital nephrotic syndrome: consensus recommendations of the ERKNet-ESPN Working Group. Nat Rev Nephrol 2021; 17:277-289. [PMID: 33514942 PMCID: PMC8128706 DOI: 10.1038/s41581-020-00384-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/30/2020] [Indexed: 01/30/2023]
Abstract
Congenital nephrotic syndrome (CNS) is a heterogeneous group of disorders characterized by nephrotic-range proteinuria, hypoalbuminaemia and oedema, which manifest in utero or during the first 3 months of life. The main cause of CNS is genetic defects in podocytes; however, it can also be caused, in rare cases, by congenital infections or maternal allo-immune disease. Management of CNS is very challenging because patients are prone to severe complications, such as haemodynamic compromise, infections, thromboses, impaired growth and kidney failure. In this consensus statement, experts from the European Reference Network for Kidney Diseases (ERKNet) and the European Society for Paediatric Nephrology (ESPN) summarize the current evidence and present recommendations for the management of CNS, including the use of renin-angiotensin system inhibitors, diuretics, anticoagulation and infection prophylaxis. Therapeutic management should be adapted to the clinical severity of the condition with the aim of maintaining intravascular euvolaemia and adequate nutrition, while preventing complications and preserving central and peripheral vessels. We do not recommend performing routine early nephrectomies but suggest that they are considered in patients with severe complications despite optimal conservative treatment, and before transplantation in patients with persisting nephrotic syndrome and/or a WT1-dominant pathogenic variant.
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Affiliation(s)
- Olivia Boyer
- grid.412134.10000 0004 0593 9113Department of Pediatric Nephrology, Reference center for Idiopathic Nephrotic Syndrome in Children and Adults, Imagine Institute, Paris University, Necker Hospital, APHP, Paris, France ,grid.508487.60000 0004 7885 7602Laboratory of Hereditary Kidney Diseases, Imagine Institute, INSERM U1163, Paris Descartes University, Paris, France
| | - Franz Schaefer
- grid.7700.00000 0001 2190 4373Division of Pediatric Nephrology, Center for Pediatrics and Adolescent Medicine, Heidelberg, Germany
| | - Dieter Haffner
- grid.10423.340000 0000 9529 9877Department of Pediatric Kidney, Liver and Metabolic Diseases, Children’s Hospital, Hannover Medical School, Hannover, Germany ,grid.10423.340000 0000 9529 9877Center for Congenital Kidney Diseases, Center for Rare Diseases, Hannover Medical School, Hannover, Germany
| | - Detlef Bockenhauer
- grid.424537.30000 0004 5902 9895UCL Department of Renal Medicine and Renal Unit, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Tuula Hölttä
- grid.15485.3d0000 0000 9950 5666Department of Pediatric Nephrology and Transplantation, The New Children’s Hospital, HUS Helsinki University Hospital, Helsinki, Finland
| | - Sandra Bérody
- grid.412134.10000 0004 0593 9113Department of Pediatric Nephrology, Reference center for Idiopathic Nephrotic Syndrome in Children and Adults, Imagine Institute, Paris University, Necker Hospital, APHP, Paris, France
| | - Hazel Webb
- grid.424537.30000 0004 5902 9895UCL Department of Renal Medicine and Renal Unit, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | | | - Beata S. Lipska-Zie˛tkiewicz
- grid.11451.300000 0001 0531 3426Clinical Genetics Unit, Department of Biology and Medical Genetics, Medical University of Gdańsk, Gdańsk, Poland ,grid.11451.300000 0001 0531 3426Centre for Rare Diseases, Medical University of Gdańsk, Gdańsk, Poland
| | - Fatih Ozaltin
- grid.14442.370000 0001 2342 7339Department of Pediatric Nephrology and Nephrogenetics Laboratory, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | - Elena Levtchenko
- grid.5596.f0000 0001 0668 7884Division of Pediatric Nephrology, Department of Pediatrics, University Hospitals Leuven; Department of Development & Regeneration, University of Leuven, Leuven, Belgium
| | - Marina Vivarelli
- grid.414125.70000 0001 0727 6809Division of Nephrology and Dialysis, Department of Pediatric Subspecialties, Bambino Gesù Pediatric Hospital Istituto di Ricerca e Cura a Carattere Scientifico (IRCCS), Rome, Italy
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17
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Murray SL, Fennelly NK, Doyle B, Lynch SA, Conlon PJ. Integration of genetic and histopathology data in interpretation of kidney disease. Nephrol Dial Transplant 2020; 35:1113-1132. [PMID: 32777081 DOI: 10.1093/ndt/gfaa176] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Indexed: 12/22/2022] Open
Abstract
For many years renal biopsy has been the gold standard for diagnosis in many forms of kidney disease. It provides rapid, accurate and clinically useful information in most individuals with kidney disease. However, in recent years, other diagnostic modalities have become available that may provide more detailed and specific diagnostic information in addition to, or instead of, renal biopsy. Genomics is one of these modalities. Previously prohibitively expensive and time consuming, it is now increasingly available and practical in a clinical setting for the diagnosis of inherited kidney disease. Inherited kidney disease is a significant cause of kidney disease, in both the adult and paediatric populations. While individual inherited kidney diseases are rare, together they represent a significant burden of disease. Because of the heterogenicity of inherited kidney disease, diagnosis and management can be a challenge and often multiple diagnostic modalities are needed to arrive at a diagnosis. We present updates in genomic medicine for renal disease, how genetic testing integrates with our knowledge of renal histopathology and how the two modalities may interact to enhance patient care.
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Affiliation(s)
- Susan L Murray
- Department of Nephrology and Transplantation, Beaumont Hospital, Dublin, Ireland.,Department of Medicine, Royal College of Surgeons, Dublin, Ireland
| | | | - Brendan Doyle
- Department of Pathology, Beaumont Hospital, Dublin, Ireland
| | - Sally Ann Lynch
- National Rare Disease Office Mater Hospital Dublin, Dublin, Ireland
| | - Peter J Conlon
- Department of Nephrology and Transplantation, Beaumont Hospital, Dublin, Ireland.,Department of Medicine, Royal College of Surgeons, Dublin, Ireland
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18
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Hashemi SS, Zare-Abdollahi D, Bakhshandeh MK, Vafaee A, Abolhasani S, Inanloo Rahatloo K, DanaeeFard F, Farboodi N, Rohani M, Alavi A. Clinical spectrum in multiple families with primary COQ 10 deficiency. Am J Med Genet A 2020; 185:440-452. [PMID: 33215859 DOI: 10.1002/ajmg.a.61983] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 11/01/2020] [Accepted: 11/02/2020] [Indexed: 12/30/2022]
Abstract
Coenzyme Q10/ COQ10 , an essential cofactor in the electron-transport chain is involved in ATP production. Primary COQ10 deficiency is clinically and genetically a heterogeneous group of mitochondrial disorders caused by defects in the COQ10 synthesis pathway. Its mode of inheritance is autosomal recessive and it is characterized by metabolic abnormalities and multisystem involvement including neurological features. Mutations in 10 genes have been identified concerning this group of diseases, so far. Among those, variants of the COQ7 gene are very rare and confined to three patients with Asian ancestry. Here, we present the clinical features and results of whole-exome sequencing (WES) of three Iranian unrelated families affected by primary COQ10 deficiency. Three homozygous variants in COQ2, COQ4, and COQ7 genes were identified. Candidate variants of the COQ2 and COQ4 genes were novel and associated with the cerebellar signs and multisystem involvement, whereas, the known variant in COQ7 was associated with a mild phenotype that was initially diagnosed as hereditary spastic paraplegia (HSP). This variant has already been reported in a Canadian girl with similar presentations that also originated from Iran suggesting both patients may share a common ancestor. Due to extensive heterogeneity in this group of disorders, and overlap with other mitochondrial/neurological disorders, WES may be helpful to distinguish primary coenzyme Q10 deficiency from other similar conditions. Given that some features of primary coenzyme Q10 deficiency may improve with exogenous COQ10 , early diagnosis is very important.
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Affiliation(s)
- Seyyed S Hashemi
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Davood Zare-Abdollahi
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Mohammad K Bakhshandeh
- Department of Pediatrics, Faculty of Medicine, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | - Amirreza Vafaee
- Department of Orthopedics, Tehran University of Medical Sciences, Tehran, Iran
| | - Sona Abolhasani
- Department of Neurology, Tabriz University of Medical Sciences, Tabriz, Iran
| | | | - Fardad DanaeeFard
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | | | - Mohammad Rohani
- Department of Neurology, Hazrat Rasool Hospital, Iran University of Medical Sciences, Tehran, Iran
| | - Afagh Alavi
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
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19
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Compound heterozygous inheritance of two novel COQ2 variants results in familial coenzyme Q deficiency. Orphanet J Rare Dis 2020; 15:320. [PMID: 33187544 PMCID: PMC7662744 DOI: 10.1186/s13023-020-01600-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 10/26/2020] [Indexed: 12/20/2022] Open
Abstract
Background Primary coenzyme Q10 deficiency is a rare disease that results in diverse and variable clinical manifestations. Nephropathy, myopathy and neurologic involvement are commonly associated, however retinopathy has also been observed with certain pathogenic variants of genes in the coenzyme Q biosynthesis pathway. In this report, we describe a novel presentation of the disease that includes nephropathy and retinopathy without neurological involvement, and which is the result of a compound heterozygous state arising from the inheritance of two recessive potentially pathogenic variants, previously not described. Materials and methods Retrospective report, with complete ophthalmic examination, multimodal imaging, electroretinography, and whole exome sequencing performed on a family with three affected siblings. Results We show that affected individuals in the described family inherited two heterozygous variants of the COQ2 gene, resulting in a frameshift variant in one allele, and a predicted deleterious missense variant in the second allele (c.288dupC,p.(Ala97Argfs*56) and c.376C > G,p.(Arg126Gly) respectively). Electroretinography results were consistent with rod-cone dystrophy in the affected individuals. All affected individuals in the family exhibited the characteristic retinopathy as well as end-stage nephropathy, without evidence of any neurological involvement. Conclusions We identified two novel compound heterozygous variants of the COQ2 gene that result in primary coenzyme Q deficiency. Targeted sequencing of coenzyme Q biosynthetic pathway genes may be useful in diagnosing oculorenal clinical presentations syndromes not explained by more well known syndromes (e.g., Senior-Loken and Bardet-Biedl syndromes).
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20
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Becherucci F, Landini S, Cirillo L, Mazzinghi B, Romagnani P. Look Alike, Sound Alike: Phenocopies in Steroid-Resistant Nephrotic Syndrome. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:E8363. [PMID: 33198123 PMCID: PMC7696007 DOI: 10.3390/ijerph17228363] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 10/30/2020] [Accepted: 11/10/2020] [Indexed: 12/11/2022]
Abstract
Steroid-resistant nephrotic syndrome (SRNS) is a clinical picture defined by the lack of response to standard steroid treatment, frequently progressing toward end-stage kidney disease. The genetic basis of SRNS has been thoroughly explored since the end of the 1990s and especially with the advent of next-generation sequencing. Genetic forms represent about 30% of cases of SRNS. However, recent evidence supports the hypothesis that "phenocopies" could account for a non-negligible fraction of SRNS patients who are currently classified as non-genetic, paving the way for a more comprehensive understanding of the genetic background of the disease. The identification of phenocopies is mandatory in order to provide patients with appropriate clinical management and to inform therapy. Extended genetic testing including phenocopy genes, coupled with reverse phenotyping, is recommended for all young patients with SRNS to avoid unnecessary and potentially harmful diagnostic procedures and treatment, and for the reclassification of the disease. The aim of this work is to review the main steps of the evolution of genetic testing in SRNS, demonstrating how a paradigm shifting from "forward" to "reverse" genetics could significantly improve the identification of the molecular mechanisms of the disease, as well as the overall clinical management of affected patients.
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Affiliation(s)
- Francesca Becherucci
- Pediatric Nephrology and Dialysis Unit, Meyer Children’s Hospital, Viale Pieraccini 24, 50139 Florence, Italy; (L.C.); (B.M.); (P.R.)
| | - Samuela Landini
- Department of Biomedical, Experimental and Clinical Science “Mario Serio”, University of Florence, Viale Morgagni 50, 50134 Florence, Italy;
| | - Luigi Cirillo
- Pediatric Nephrology and Dialysis Unit, Meyer Children’s Hospital, Viale Pieraccini 24, 50139 Florence, Italy; (L.C.); (B.M.); (P.R.)
- Department of Biomedical, Experimental and Clinical Science “Mario Serio”, University of Florence, Viale Morgagni 50, 50134 Florence, Italy;
| | - Benedetta Mazzinghi
- Pediatric Nephrology and Dialysis Unit, Meyer Children’s Hospital, Viale Pieraccini 24, 50139 Florence, Italy; (L.C.); (B.M.); (P.R.)
| | - Paola Romagnani
- Pediatric Nephrology and Dialysis Unit, Meyer Children’s Hospital, Viale Pieraccini 24, 50139 Florence, Italy; (L.C.); (B.M.); (P.R.)
- Department of Biomedical, Experimental and Clinical Science “Mario Serio”, University of Florence, Viale Morgagni 50, 50134 Florence, Italy;
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21
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Labat-de-Hoz L, Alonso MA. The formin INF2 in disease: progress from 10 years of research. Cell Mol Life Sci 2020; 77:4581-4600. [PMID: 32451589 PMCID: PMC11104792 DOI: 10.1007/s00018-020-03550-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 05/04/2020] [Accepted: 05/13/2020] [Indexed: 02/07/2023]
Abstract
Formins are a conserved family of proteins that primarily act to form linear polymers of actin. Despite their importance to the normal functioning of the cytoskeleton, for a long time, the only two formin genes known to be a genetic cause of human disorders were DIAPH1 and DIAPH3, whose mutation causes two distinct forms of hereditary deafness. In the last 10 years, however, the formin INF2 has emerged as an important target of mutations responsible for the appearance of focal segmental glomerulosclerosis, which are histological lesions associated with glomerulus degeneration that often leads to end-stage renal disease. In some rare cases, focal segmental glomerulosclerosis concurs with Charcot-Marie-Tooth disease, which is a degenerative neurological disorder affecting peripheral nerves. All known INF2 gene mutations causing disease map to the exons encoding the amino-terminal domain. In this review, we summarize the structure, biochemical features and functions of INF2, conduct a systematic and comprehensive analysis of the pathogenic INF2 mutations, including a detailed study exon-by-exon of patient cases and mutations, address the impact of the pathogenic mutations on the structure, regulation and known functions of INF2, draw a series of conclusions that could be useful for INF2-related disease diagnosis, and suggest lines of research for future work on the molecular mechanisms by which INF2 causes disease.
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Affiliation(s)
- Leticia Labat-de-Hoz
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, Madrid, Spain
| | - Miguel A Alonso
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, Madrid, Spain.
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Lipska-Ziętkiewicz BS, Ozaltin F, Hölttä T, Bockenhauer D, Bérody S, Levtchenko E, Vivarelli M, Webb H, Haffner D, Schaefer F, Boyer O. Genetic aspects of congenital nephrotic syndrome: a consensus statement from the ERKNet-ESPN inherited glomerulopathy working group. Eur J Hum Genet 2020; 28:1368-1378. [PMID: 32467597 PMCID: PMC7608398 DOI: 10.1038/s41431-020-0642-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Revised: 03/03/2020] [Accepted: 03/10/2020] [Indexed: 01/23/2023] Open
Abstract
Congenital nephrotic syndrome (CNS) is a heterogeneous group of disorders presenting with massive proteinuria within the first 3 months of life almost inevitably leading to end-stage kidney disease. The Work Group for the European Reference Network for Kidney Diseases (ERKNet) and the European Society for Pediatric Nephrology (ESPN) has developed consensus statement on genetic aspects of CNS diagnosis and management. The presented expert opinion recommends genetic diagnostics as the key diagnostic test to be ordered already during the initial evaluation of the patient, discusses which phenotyping workup should be performed and presents known genotype-phenotype correlations.
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Affiliation(s)
- Beata Stefania Lipska-Ziętkiewicz
- Clinical Genetics Unit, Department of Biology and Medical Genetics, Medical University of Gdańsk, Gdańsk, Poland.
- Centre for Rare Diseases, Medical University of Gdańsk, Gdańsk, Poland.
| | - Fatih Ozaltin
- Department of Pediatric Nephrology and Nephrogenetics Laboratory, Hacettepe University Faculty of Medicine, Ankara, Turkey.
| | - Tuula Hölttä
- Department of Pediatric Nephrology and Transplantation, The New Children's Hospital, HUS Helsinki University Hospital, Helsinki, Finland
| | - Detlef Bockenhauer
- UCL Department of Renal Medicine and Renal Unit, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Sandra Bérody
- Department of Pediatric Nephrology, Reference Center for Hereditary Kidney Diseases (MARHEA), Necker Hospital, APHP, 75015, Paris, France
| | - Elena Levtchenko
- Division of Pediatric Nephrology, Department of Pediatrics, University Hospitals Leuven; Department of Development & Regeneration, University of Leuven, Leuven, Belgium
| | - Marina Vivarelli
- Division of Nephrology and Dialysis, Department of Pediatric Subspecialties, Bambino Gesù Pediatric Hospital and Research Center, Rome, Italy
| | - Hazel Webb
- UCL Department of Renal Medicine and Renal Unit, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Dieter Haffner
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School Children's Hospital, Hannover, Germany
- Center for Congenital Kidney Diseases, Center for Rare Diseases, Hannover Medical School, Hannover, Germany
| | - Franz Schaefer
- Division of Pediatric Nephrology, Center for Pediatrics and Adolescent Medicine, Heidelberg, Germany.
| | - Olivia Boyer
- Department of Pediatric Nephrology, Reference Center for Hereditary Kidney Diseases (MARHEA), Necker Hospital, APHP, 75015, Paris, France
- Laboratory of Hereditary Kidney Diseases, Imagine Institute, INSERM, Paris Descartes University, U1163, Paris, France
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Mena-Gutierrez AM, Reeves-Daniel AM, Jay CL, Freedman BI. Practical Considerations for APOL1 Genotyping in the Living Kidney Donor Evaluation. Transplantation 2020; 104:27-32. [PMID: 31449181 DOI: 10.1097/tp.0000000000002933] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND Association between the apolipoprotein L1 gene (APOL1) and nephropathy has altered the epidemiology of chronic kidney disease. In addition, donor APOL1 genotypes play important roles in the time to allograft failure in kidneys transplanted from deceased donors and the safety of living kidney donation. METHODS This article reviews genetic testing for inherited kidney disease in living kidney donors to improve donor safety. APOL1 genotyping in donors with recent African ancestry is considered. RESULTS Based on current data, transplant physicians should discuss APOL1 genotyping with potential living kidney donors self-reporting recent African ancestry. Until results from APOL1 Long-term Kidney Transplant Outcomes Network ancillary studies are available, we present practical approaches from our experience for considering APOL1 genotyping in the living donor evaluation. CONCLUSIONS Transplant physicians should inform potential living kidney donors at risk for APOL1-associated nephropathy about the gene and possibility of genetic testing early in the donor evaluation, well before scheduling the donor nephrectomy. Transplant programs must weigh risks of performing a donor nephrectomy in those with 2 APOL1 renal risk variants (high-risk genotypes), particularly younger individuals. Our program counsels kidney donors with APOL1 high-risk genotypes in the same fashion as with risk genotypes in other nephropathy genes. Because most African American kidney donor candidates lacking hypertension, proteinuria and reduced kidney function after workup will not possess APOL1 high-risk genotypes, genetic testing is unlikely to markedly increase donor declines and may reassure donors with regard to their long-term kidney outcomes, potentially increasing the number of African American donors.
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Affiliation(s)
- Alejandra M Mena-Gutierrez
- Section on Nephrology, Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, NC
| | - Amber M Reeves-Daniel
- Section on Nephrology, Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, NC
| | - Colleen L Jay
- Department of Surgery, Wake Forest School of Medicine, Winston-Salem, NC
| | - Barry I Freedman
- Section on Nephrology, Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, NC
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24
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Ahram DF, Aggarwal VS, Sanna-Cherchi S. Phenocopies, Phenotypic Expansion, and Coincidental Diagnoses: Time to Abandon Targeted Gene Panels? Am J Kidney Dis 2020; 76:451-453. [PMID: 32807573 DOI: 10.1053/j.ajkd.2020.07.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Accepted: 07/09/2020] [Indexed: 11/11/2022]
Affiliation(s)
- Dina F Ahram
- Division of Nephrology, Columbia University, New York, NY; Department of Pathology & Cell Biology, Columbia University, New York, NY
| | - Vimla S Aggarwal
- Department of Pathology & Cell Biology, Columbia University, New York, NY
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Justine Perrin R, Rousset‐Rouvière C, Garaix F, Cano A, Conrath J, Boyer O, Tsimaratos M. COQ6 mutation in patients with nephrotic syndrome, sensorineural deafness, and optic atrophy. JIMD Rep 2020; 54:37-44. [PMID: 32685349 PMCID: PMC7358665 DOI: 10.1002/jmd2.12068] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 06/18/2019] [Accepted: 06/24/2019] [Indexed: 11/25/2022] Open
Abstract
INTRODUCTION Primary coenzyme Q10 (CoQ10) deficiencies are a group of mitochondrial disorders that has proven responsiveness to replacement therapy. Mutations in enzymes involved in the biosynthesis of CoQ10 genes are associated with these deficits. The clinical presentation of this rare autosomal recessive disorder is heterogeneous and depends on the gene involved. Mutations in the COQ2, COQ6, PDSS2, and ADCK4 genes are responsible for steroid-resistant nephrotic syndrome (SRNS), which is associated with extra-renal symptoms. Previous studies have reported COQ6 mutations in 11 patients from five different families presenting with SRNS and sensorineural deafness. CASE REPORTS Our study reports the cases of two brothers of Turkish origin with renal failure and sensorineural deafness associated with COQ6 mutations responsible of CoQ10 deficiency. Optical symptoms were present in the eldest, that improved with Idebenone. CONCLUSION/DISCUSSION For the first time, COQ6 mutation with optical involvement is associated with renal and hearing impairment. Although the response to replacement CoQ10 therapy was difficult to evaluate, we think that this treatment was able to stop the disease progression in both patients, and even to prevent the occurrence/development of optical and neurological impairment in the younger brother. Mitochondrial dysfunction secondary to CoQ10 deficiency should always be suspected in patients with SRNS and extra-renal symptoms. Early recognition of this genetic SRNS is mandatory since SRNS can be avoided by adequate treatment based on CoQ10 supplement or an analogue. All cases of primary CoQ10 deficiency should be treated at an early stage to limit the progression of lesions and prevent the emergence of new symptoms.
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Affiliation(s)
- R. Justine Perrin
- Assistance Public Hôpitaux de MarseilleService Multidisciplinaire TimoneMarseilleFrance
| | | | - Florentine Garaix
- Assistance Public Hôpitaux de MarseilleService Multidisciplinaire TimoneMarseilleFrance
| | - Aline Cano
- Assistance Public Hôpitaux de MarseilleService de pédiatrie et NeurologieMarseilleFrance
| | - John Conrath
- Clinique Monticelli, OphtalmologieMarseilleFrance
| | - Olivia Boyer
- Hopital NeckerNéphrologie PediatriqueParisFrance
| | - Michel Tsimaratos
- Assistance Public Hôpitaux de MarseilleService Multidisciplinaire TimoneMarseilleFrance
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26
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Demir E, Caliskan Y. Variations of type IV collagen-encoding genes in patients with histological diagnosis of focal segmental glomerulosclerosis. Pediatr Nephrol 2020; 35:927-936. [PMID: 31254113 DOI: 10.1007/s00467-019-04282-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 05/01/2019] [Accepted: 05/31/2019] [Indexed: 01/07/2023]
Abstract
Focal segmental glomerulosclerosis (FSGS), an important cause of end-stage kidney disease (ESKD), covers a spectrum of clinicopathological syndromes sharing a common glomerular lesion, based on an injury of podocytes caused by diverse insults to glomeruli. Although it is well expressed in many reports that the term FSGS is not useful and applicable to a single disease, particularly in genetic studies, FSGS continues to be used as a single clinical diagnosis. Distinguishing genetic forms of FSGS is important for the treatment and overall prognosis because secondary forms of FSGS, produced by rare pathogenic variations in podocyte genes, are not good candidates for immunosuppressive treatment. Over the past decade, several next generation sequencing (NGS) methods have been used to investigate the patients with steroid resistance nephrotic syndrome (SRNS) or FSGS. Pathogenic variants in COL4A3, COL4A4, or COL4A5 genes have been frequently identified in patients with histologic diagnosis of FSGS. The contribution of these mostly heterozygous genetic variations in FSGS pathogenesis and the clinical course of patients with these variations have not been well characterized. This review emphasizes the importance of appropriate approach in selection and diagnosis of cases and interpretation of the genetic data in these studies and suggests a detailed review of existing clinical variant databases using newly available population genetic data.
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Affiliation(s)
- Erol Demir
- Division of Nephrology, Department of Internal Medicine, Istanbul School of Medicine, Istanbul University, Capa, Fatih, 34093, Istanbul, Turkey
| | - Yasar Caliskan
- Division of Nephrology, Department of Internal Medicine, Istanbul School of Medicine, Istanbul University, Capa, Fatih, 34093, Istanbul, Turkey.
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27
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Liu S, Narumi R, Ikeda N, Morita O, Tasaki J. Chemical-induced craniofacial anomalies caused by disruption of neural crest cell development in a zebrafish model. Dev Dyn 2020; 249:794-815. [PMID: 32314458 PMCID: PMC7384000 DOI: 10.1002/dvdy.179] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 04/12/2020] [Accepted: 04/13/2020] [Indexed: 12/11/2022] Open
Abstract
Background Craniofacial anomalies are among the most frequent birth defects worldwide, and are thought to be caused by gene‐environment interactions. Genetically manipulated zebrafish simulate human diseases and provide great advantages for investigating the etiology and pathology of craniofacial anomalies. Although substantial advances have been made in understanding genetic factors causing craniofacial disorders, limited information about the etiology by which environmental factors, such as teratogens, induce craniofacial anomalies is available in zebrafish. Results Zebrafish embryos displayed craniofacial malformations after teratogen treatments. Further observations revealed characteristic disruption of chondrocyte number, shape and stacking. These findings suggested aberrant development of cranial neural crest (CNC) cells, which was confirmed by gene expression analysis of the CNC. Notably, these observations suggested conserved etiological pathways between zebrafish and mammals including human. Furthermore, several of these chemicals caused malformations of the eyes, otic vesicle, and/or heart, representing a phenocopy of neurocristopathy, and these chemicals altered the expression levels of the responsible genes. Conclusions Our results demonstrate that chemical‐induced craniofacial malformation is caused by aberrant development of neural crest. This study indicates that zebrafish provide a platform for investigating contributions of environmental factors as causative agents of craniofacial anomalies and neurocristopathy.
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Affiliation(s)
- Shujie Liu
- R&D, Safety Science Research, Kao Corporation, Tochigi, Japan
| | - Rika Narumi
- R&D, Safety Science Research, Kao Corporation, Tochigi, Japan
| | - Naohiro Ikeda
- R&D, Safety Science Research, Kao Corporation, Tochigi, Japan
| | - Osamu Morita
- R&D, Safety Science Research, Kao Corporation, Tochigi, Japan
| | - Junichi Tasaki
- R&D, Safety Science Research, Kao Corporation, Tochigi, Japan
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28
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Bensimhon AR, Williams AE, Gbadegesin RA. Treatment of steroid-resistant nephrotic syndrome in the genomic era. Pediatr Nephrol 2019; 34:2279-2293. [PMID: 30280213 PMCID: PMC6445770 DOI: 10.1007/s00467-018-4093-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 09/13/2018] [Accepted: 09/18/2018] [Indexed: 12/25/2022]
Abstract
The pathogenesis of steroid-resistant nephrotic syndrome (SRNS) is not completely known. Recent advances in genomics have elucidated some of the molecular mechanisms and pathophysiology of the disease. More than 50 monogenic causes of SRNS have been identified; however, these genes are responsible for only a small fraction of SRNS in outbred populations. There are currently no guidelines for genetic testing in SRNS, but evidence from the literature suggests that testing should be guided by the genetic architecture of the disease in the population. Notably, most genetic forms of SRNS do not respond to current immunosuppressive therapies; however, a small subset of patients with monogenic SRNS will achieve partial or complete remission with specific immunomodulatory agents, presumably due to non-immunosuppressive effects of these agents. We suggest a pragmatic approach to the therapy of genetic SRNS, as there is no evidence-based algorithm for the management of the disease.
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Affiliation(s)
- Adam R. Bensimhon
- Department of Pediatrics, Division of Nephrology, Duke University Medical Center, Durham, NC 27710, USA
| | - Anna E. Williams
- Department of Pediatrics, Division of Nephrology, Duke University Medical Center, Durham, NC 27710, USA
| | - Rasheed A. Gbadegesin
- Department of Pediatrics, Division of Nephrology, Duke University Medical Center, Durham, NC 27710, USA,Department of Medicine, Division of Nephrology, Duke University Medical Center, Durham, NC 27710, USA,Duke Molecular Physiology Institute, Durham, NC, USA
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29
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Wu X, Wang W, Liu Y, Chen W, Zhao L. A steroid-resistant nephrotic syndrome in an infant resulting from a consanguineous marriage with COQ2 and ARSB gene mutations: a case report. BMC MEDICAL GENETICS 2019; 20:165. [PMID: 31660881 PMCID: PMC6816174 DOI: 10.1186/s12881-019-0898-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 09/25/2019] [Indexed: 12/03/2022]
Abstract
Background Treatment of steroid-resistant nephrotic syndrome (SRNS) remains a challenge for paediatricians. SRNS accounts for 10~20% of childhood cases of nephrotic syndrome (NS). Individuals with SRNS overwhelmingly progress to chronic kidney disease (CKD) and end-stage kidney disease (ESRD). Genetic research is of great significance for diagnosis and treatment. More than 39 recessive or dominant genes have been found to cause human SRNS, including COQ2. COQ2 gene mutations not only cause primary coenzyme Q10 deficiency but also cause SRNS without extrarenal manifestations. The concept of COQ2 nephropathy has been proposed for a long time. Mutations in the COQ2 gene have rarely been reported. Worldwide, only 5 cases involving 4 families have been reported. Case presentation We present the case of a 6-month-old girl with steroid-resistant glomerulopathy due to a COQ2 defect with no additional systemic symptoms. The patient was identified as a homozygote for the c.832 T > C (p. Cys278Arg) missense mutation and a single base homozygous mutation in ARSB gene in c.1213 + 1G > A. The father and mother were heterozygous mutation carriers in both COQ2 and ARSB, and her healthy sister was only a heterozygous mutation carrier in COQ2. In this case, hormone therapy was ineffective, and progressive deterioration of renal function occurred within 1 week after onset, leading to acute renal failure and eventual death. Conclusions We reported a consanguinity married family which had COQ2 and ARSB dual mutant. Kidney diseases caused by COQ2 gene mutations can manifest as SRNS, with poor prognosis. The C. 832 T > c (p.csc 278arg) is a new mutation site. Genetic assessment for children with steroid-resistant nephrotic syndrome, especially in infancy, is very important. Families with a clear family history should receive genetic counselling and prenatal examinations, and children without a family phenotype should also receive genetic screening as early as possible.
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Affiliation(s)
- Xia Wu
- Department of Nephrology, Tianjin Children's Hospital, 238 Longyan Road, Beichen District, Tianjin, China
| | - Wenhong Wang
- Department of Nephrology, Tianjin Children's Hospital, 238 Longyan Road, Beichen District, Tianjin, China.
| | - Yan Liu
- Department of Nephrology, Tianjin Children's Hospital, 238 Longyan Road, Beichen District, Tianjin, China
| | - Wenyu Chen
- Department of Nephrology, Tianjin Children's Hospital, 238 Longyan Road, Beichen District, Tianjin, China
| | - Linsheng Zhao
- Department of Pathology, Tianjin Children's Hospital, 238 Longyan Road, Beichen District, Tianjin, China
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30
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Molecular stratification of idiopathic nephrotic syndrome. Nat Rev Nephrol 2019; 15:750-765. [DOI: 10.1038/s41581-019-0217-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/20/2019] [Indexed: 01/03/2023]
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31
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Gribouval O, Boyer O, Hummel A, Dantal J, Martinez F, Sberro-Soussan R, Etienne I, Chauveau D, Delahousse M, Lionet A, Allard J, Pouteil Noble C, Tête MJ, Heidet L, Antignac C, Servais A. Identification of genetic causes for sporadic steroid-resistant nephrotic syndrome in adults. Kidney Int 2019; 94:1013-1022. [PMID: 30348286 DOI: 10.1016/j.kint.2018.07.024] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 06/18/2018] [Accepted: 07/12/2018] [Indexed: 01/15/2023]
Abstract
Monogenic forms of Steroid-Resistant Nephrotic Syndrome (SRNS) have been widely characterized, but genetic screening paradigms preferentially address congenital, infantile onset, and familial cases. Our aim was to characterize the distribution of disease-causing gene mutations in adults with sporadic SRNS or focal segmental glomerulosclerosis (FSGS). We selected adult patients with non-syndromic, biopsy-proven FSGS or SRNS in the absence of known family history. Strict clinical criteria included lack of response to glucocorticoids and cyclosporine, and no recurrence after kidney transplantation. Mutations in SRNS genes were detected using a targeted gene panel. Sixteen of 135 tested participants (11.8%) carried pathogenic mutations in monogenic SRNS genes, and 14 others (10.4%) carried two APOL1 high-risk alleles. Autosomal recessive disease was diagnosed in 5 participants, autosomal dominant disease in 9, and X-linked disease in 2. Four participants carried a de novo heterozygous mutation. Among the 16 participants with identified mutations in monogenic SNRS genes, 7 (43.7%) had type IV collagen mutations. Mutations in monogenic SNRS genes were identified primarily in participants with proteinuria onset before 25 years of age, while the age at disease onset was variable in those with APOL1 high-risk genotype. Mean age at diagnosis was lower and renal survival was worse in participants with identified mutations in SNRS genes than in those without mutations. We found a significant rate of pathogenic mutations in adults with SRNS, with Type IV collagen mutations being the most frequent. These findings may have immediate impact on clinical practice.
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Affiliation(s)
- Olivier Gribouval
- Inserm U1163, Imagine Institute, Paris Descartes University, Paris, France
| | - Olivia Boyer
- Inserm U1163, Imagine Institute, Paris Descartes University, Paris, France; Pediatric Nephrology, Centre de référence des Maladies Rénales Héréditaires de l'Enfant et de l'Adulte, Necker Hospital, Paris, France
| | - Aurélie Hummel
- Inserm U1163, Imagine Institute, Paris Descartes University, Paris, France; Adult Nephrology & Transplantation, Centre de référence des Maladies Rénales Héréditaires de l'Enfant et de l'Adulte, Necker Hospital, Paris, France
| | | | - Frank Martinez
- Adult Nephrology & Transplantation, Centre de référence des Maladies Rénales Héréditaires de l'Enfant et de l'Adulte, Necker Hospital, Paris, France
| | - Rebecca Sberro-Soussan
- Adult Nephrology & Transplantation, Centre de référence des Maladies Rénales Héréditaires de l'Enfant et de l'Adulte, Necker Hospital, Paris, France
| | - Isabelle Etienne
- Nephrology Department, Hôpital de Bois-Guillaume, CHU Rouen, Rouen, France
| | - Dominique Chauveau
- Department of Nephrology and Organ Transplantation, CHU Rangueil, Toulouse, France
| | | | - Arnaud Lionet
- Nephrology Department, Hôpital Huriez, CHU Lille, Lille, France
| | | | - Claire Pouteil Noble
- Nephrology-Transplantation Department, Hôpital Edouard Herriot, Lyon I University, Lyon, France
| | - Marie-Josèphe Tête
- Inserm U1163, Imagine Institute, Paris Descartes University, Paris, France
| | - Laurence Heidet
- Inserm U1163, Imagine Institute, Paris Descartes University, Paris, France; Pediatric Nephrology, Centre de référence des Maladies Rénales Héréditaires de l'Enfant et de l'Adulte, Necker Hospital, Paris, France; Genetic Department, Necker Hospital, APHP, Paris, France
| | - Corinne Antignac
- Inserm U1163, Imagine Institute, Paris Descartes University, Paris, France; Genetic Department, Necker Hospital, APHP, Paris, France.
| | - Aude Servais
- Inserm U1163, Imagine Institute, Paris Descartes University, Paris, France; Adult Nephrology & Transplantation, Centre de référence des Maladies Rénales Héréditaires de l'Enfant et de l'Adulte, Necker Hospital, Paris, France.
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32
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Snoek R, Nguyen TQ, van der Zwaag B, van Zuilen AD, Kruis HME, van Gils-Verrij LA, Goldschmeding R, Knoers NVAM, Rookmaaker MB, van Eerde AM. Importance of Genetic Diagnostics in Adult-Onset Focal Segmental Glomerulosclerosis. Nephron Clin Pract 2019; 142:351-358. [PMID: 31096240 DOI: 10.1159/000499937] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 03/27/2019] [Indexed: 12/31/2022] Open
Abstract
Focal segmental glomerulosclerosis (FSGS) is a histological pattern of podocyte and glomerulus injury. FSGS can be primary and secondary to other diseases or due to a genetic cause. Strikingly, genetic causes for adult-onset FSGS are often overlooked, likely because identifying patients with genetic forms of FSGS based on clinical presentation and histopathology is difficult. Yet diagnosing genetic FSGS does not only have implications for prognostication and therapy but also for family and family planning. In this case series, we present 3 adult patients who presented with advanced renal disease with the histological picture of FSGS and proved to have a genetic cause of the disease, namely, variants in INF2, COL4A4 and HNF1B, respectively. We show the possibilities of identifying genetic FSGS based on clinical clues of a positive family history, early age at onset of disease, and/or severe therapy-resistant disease. We discuss ways to select the method of genetic testing for individual patients. Finally, we examine how the judicious use of genetic investigations can obviate potential harmful diagnostic procedures and direct clinical decisions in patients and their relatives.
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Affiliation(s)
- Rozemarijn Snoek
- Department of Genetics and Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Tri Q Nguyen
- Department of Pathology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Bert van der Zwaag
- Department of Genetics and Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Arjan D van Zuilen
- Department of Nephrology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Hannah M E Kruis
- Department of Nephrology, Elyse Renal Clinic, Woerden, The Netherlands
| | | | - Roel Goldschmeding
- Department of Pathology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Nine V A M Knoers
- Department of Genetics and Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, The Netherlands.,Department of Genetics, University Medical Center Groningen, Groningen, The Netherlands
| | - Maarten B Rookmaaker
- Department of Nephrology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Albertien M van Eerde
- Department of Genetics and Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, The Netherlands,
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33
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Intrinsic tumor necrosis factor-α pathway is activated in a subset of patients with focal segmental glomerulosclerosis. PLoS One 2019; 14:e0216426. [PMID: 31095586 PMCID: PMC6522053 DOI: 10.1371/journal.pone.0216426] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 04/20/2019] [Indexed: 01/09/2023] Open
Abstract
Focal segmental glomerulosclerosis (FSGS) is frequently found in biopsies of patients with steroid resistant nephrotic syndrome (SRNS). The pathogenesis of SRNS/FSGS is often unknown and the disease will recur in up to 50% of patients post-transplant, indicating the presence of circulating podocyte-toxic factor(s). Several studies have reported clinical improvement after anti-TNFα therapy. However, prediction of the clinical outcome in SRNS/FSGS is difficult, and novel predictive biomarkers are needed. An image-based assay, which measures disassembly of focal adhesion complexes in cultured podocytes, was used to ascertain the presence of podocyte toxic activity in SRNS/FSGS sera. Expression of TNFα pathway genes was analysed in the Nephroseq FSGS cohort and in cultured podocytes treated with SRNS/FSGS sera. Podocyte toxic activity was detected in 48/96 SRNS/FSGS patients. It did not correlate with serum TNFα levels, age, sex, ethnicity or glomerular filtration rate. In ~25% of the toxic samples, the toxicity was strongly inhibited by blockade of TNFα signaling. Transcriptional profiling of human FSGS biopsies and podocytes treated with FSGS sera revealed significant increases in expression of TNFα pathway genes. We identified patients with serum podocyte toxic activity who may be at risk for FSGS recurrence, and those patients in whom serum podocyte toxicity may be reversed by TNFα blockade. Activation of TNFα pathway genes occurs in podocytes of FSGS patients suggesting a causative effect of this pathway in response to circulating factor(s). In vitro analyses of patient sera may stratify patients according to prognostic outcomes and potential responses to specific clinical interventions.
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Sengupta P, Burgaleta M, Zamora-López G, Basora A, Sanjuán A, Deco G, Sebastian-Galles N. Traces of statistical learning in the brain's functional connectivity after artificial language exposure. Neuropsychologia 2019; 124:246-253. [PMID: 30521815 DOI: 10.1016/j.neuropsychologia.2018.12.001] [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: 06/01/2018] [Revised: 11/27/2018] [Accepted: 12/01/2018] [Indexed: 10/27/2022]
Abstract
Our environment is full of statistical regularities, and we are attuned to learn about these regularities by employing Statistical Learning (SL), a domain-general ability that enables the implicit detection of probabilistic regularities in our surrounding environment. The role of brain connectivity on SL has been previously explored, highlighting the relevance of structural and functional connections between frontal, parietal, and temporal cortices. However, whether SL can induce changes in the functional connections of the resting state brain has yet to be investigated. To address this question, we applied a pre-post design where participants (n = 38) were submitted to resting-state fMRI acquisition before and after in-scanner exposure to either an artificial language stream (formed by 4 concatenated words) or a random audio stream. Our results showed that exposure to an artificial language stream significantly changed (corrected p < 0.05) the functional connectivity between Right Posterior Cingulum and Left Superior Parietal Lobule. This suggests that functional connectivity between brain networks supporting attentional and working memory processes may play an important role in statistical learning.
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Affiliation(s)
- Pallabi Sengupta
- Center for Brain and Cognition, Department of Technology, Universitat Pompeu Fabra, 08018 Barcelona, Spain.
| | - Miguel Burgaleta
- Center for Brain and Cognition, Department of Technology, Universitat Pompeu Fabra, 08018 Barcelona, Spain.
| | - Gorka Zamora-López
- Center for Brain and Cognition, Department of Technology, Universitat Pompeu Fabra, 08018 Barcelona, Spain.
| | - Anna Basora
- Center for Brain and Cognition, Department of Technology, Universitat Pompeu Fabra, 08018 Barcelona, Spain.
| | - Ana Sanjuán
- Center for Brain and Cognition, Department of Technology, Universitat Pompeu Fabra, 08018 Barcelona, Spain.
| | - Gustavo Deco
- Center for Brain and Cognition, Department of Technology, Universitat Pompeu Fabra, 08018 Barcelona, Spain.
| | - Nuria Sebastian-Galles
- Center for Brain and Cognition, Department of Technology, Universitat Pompeu Fabra, 08018 Barcelona, Spain.
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Siji A, Karthik KN, Pardeshi VC, Hari PS, Vasudevan A. Targeted gene panel for genetic testing of south Indian children with steroid resistant nephrotic syndrome. BMC MEDICAL GENETICS 2018; 19:200. [PMID: 30458709 PMCID: PMC6245897 DOI: 10.1186/s12881-018-0714-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2018] [Accepted: 11/07/2018] [Indexed: 01/10/2023]
Abstract
BACKGROUND Steroid resistant nephrotic syndrome (SRNS) is a genetically heterogeneous disease with significant phenotypic variability. More than 53 podocyte-expressed genes are implicated in SRNS which complicates the routine use of genetic screening in the clinic. Next generation sequencing technology (NGS) allows rapid screening of multiple genes in large number of patients in a cost-effective manner. METHODS We developed a targeted panel of 17 genes to determine relative frequency of mutations in south Indian ethnicity and feasibility of using the assay in a clinical setting. Twenty-five children with SRNS and 3 healthy individuals were screened. RESULTS In this study, novel variants including 1 pathogenic variant (2 patients) and 3 likely pathogenic variants (3 patients) were identified. In addition, 2 novel variants of unknown significance (VUS) in 2 patients (8% of total patients) were also identified. CONCLUSIONS The results show that genetic screening in SRNS using NGS is feasible in a clinical setting. However the panel needs to be screened in a larger cohort of children with SRNS in order to assess the utility of the customised targeted panel in Indian children with SRNS. Determining the prevalence of variants in Indian population and improvising the bioinformatics-based filtering strategy for a more accurate differentiation of pathogenic variants from those that are benign among the VUS will help in improving medical and genetic counselling in SRNS.
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Affiliation(s)
- Annes Siji
- Division of Molecular Medicine, St. John's Research Institute, Bangalore, India
| | - K N Karthik
- Division of Molecular Medicine, St. John's Research Institute, Bangalore, India
| | | | - P S Hari
- Division of Molecular Medicine, St. John's Research Institute, Bangalore, India
| | - Anil Vasudevan
- Division of Molecular Medicine, St. John's Research Institute, Bangalore, India. .,Department of Pediatric Nephrology, St. John's Medical College Hospital, Bangalore, India.
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Mariani LH, Bomback AS, Canetta PA, Flessner MF, Helmuth M, Hladunewich MA, Hogan JJ, Kiryluk K, Nachman PH, Nast CC, Rheault MN, Rizk DV, Trachtman H, Wenderfer SE, Bowers C, Hill-Callahan P, Marasa M, Poulton CJ, Revell A, Vento S, Barisoni L, Cattran D, D'Agati V, Jennette JC, Klein JB, Laurin LP, Twombley K, Falk RJ, Gharavi AG, Gillespie BW, Gipson DS, Greenbaum LA, Holzman LB, Kretzler M, Robinson B, Smoyer WE, Guay-Woodford LM. CureGN Study Rationale, Design, and Methods: Establishing a Large Prospective Observational Study of Glomerular Disease. Am J Kidney Dis 2018; 73:218-229. [PMID: 30420158 PMCID: PMC6348011 DOI: 10.1053/j.ajkd.2018.07.020] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 07/31/2018] [Indexed: 01/01/2023]
Abstract
RATIONALE & OBJECTIVES Glomerular diseases, including minimal change disease, focal segmental glomerulosclerosis, membranous nephropathy, and immunoglobulin A (IgA) nephropathy, share clinical presentations, yet result from multiple biological mechanisms. Challenges to identifying underlying mechanisms, biomarkers, and new therapies include the rarity of each diagnosis and slow progression, often requiring decades to measure the effectiveness of interventions to prevent end-stage kidney disease (ESKD) or death. STUDY DESIGN Multicenter prospective cohort study. SETTING & PARTICIPANTS Cure Glomerulonephropathy (CureGN) will enroll 2,400 children and adults with minimal change disease, focal segmental glomerulosclerosis, membranous nephropathy, or IgA nephropathy (including IgA vasculitis) and a first diagnostic kidney biopsy within 5 years. Patients with ESKD and those with secondary causes of glomerular disease are excluded. EXPOSURES Clinical data, including medical history, medications, family history, and patient-reported outcomes, are obtained, along with a digital archive of kidney biopsy images and blood and urine specimens at study visits aligned with clinical care 1 to 4 times per year. OUTCOMES Patients are followed up for changes in estimated glomerular filtration rate, disease activity, ESKD, and death and for nonrenal complications of disease and treatment, including infection, malignancy, cardiovascular, and thromboembolic events. ANALYTICAL APPROACH The study design supports multiple longitudinal analyses leveraging the diverse data domains of CureGN and its ancillary program. At 2,400 patients and an average of 2 years' initial follow-up, CureGN has 80% power to detect an HR of 1.4 to 1.9 for proteinuria remission and a mean difference of 2.1 to 3.0mL/min/1.73m2 in estimated glomerular filtration rate per year. LIMITATIONS Current follow-up can only detect large differences in ESKD and death outcomes. CONCLUSIONS Study infrastructure will support a broad range of scientific approaches to identify mechanistically distinct subgroups, identify accurate biomarkers of disease activity and progression, delineate disease-specific treatment targets, and inform future therapeutic trials. CureGN is expected to be among the largest prospective studies of children and adults with glomerular disease, with a broad goal to lessen disease burden and improve outcomes.
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Affiliation(s)
- Laura H Mariani
- Division of Nephrology, Department of Medicine, University of Michigan, Ann Arbor, MI; Arbor Research Collaborative for Health, Ann Arbor, MI.
| | - Andrew S Bomback
- Division of Nephrology, Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY
| | - Pietro A Canetta
- Division of Nephrology, Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY
| | - Michael F Flessner
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Department of Health and Human Services, Bethesda, MD
| | | | - Michelle A Hladunewich
- Division of Nephrology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, Canada
| | - Jonathan J Hogan
- Renal-Electrolyte and Hypertension Division, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Krzysztof Kiryluk
- Division of Nephrology, Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY
| | - Patrick H Nachman
- Division of Renal Diseases and Hypertension, Department of Medicine, University of Minnesota, Minneapolis, MN
| | - Cynthia C Nast
- Department of Pathology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Michelle N Rheault
- Division of Nephrology, Department of Pediatrics, University of Minnesota Masonic Children's Hospital, Minneapolis, MN
| | - Dana V Rizk
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL
| | - Howard Trachtman
- Division of Nephrology, Department of Pediatrics, New York University Langone Medical Center, New York, NY
| | - Scott E Wenderfer
- Renal Section, Department of Pediatrics, Baylor College of Medicine, Texas Children's Hospital, Houston, TX
| | - Corinna Bowers
- Center for Clinical and Translational Research, The Research Institute at Nationwide Children's Hospital, Columbus, OH
| | | | - Maddalena Marasa
- Division of Nephrology, Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY
| | - Caroline J Poulton
- Division of Nephrology and Hypertension, Kidney Center, Department of Medicine, University of North Carolina, Chapel Hill, NC
| | - Adelaide Revell
- Center for Clinical and Translational Research, The Research Institute at Nationwide Children's Hospital, Columbus, OH
| | - Suzanne Vento
- Division of Nephrology, Department of Pediatrics, New York University Langone Medical Center, New York, NY
| | | | - Dan Cattran
- Division of Nephrology, University Health Network, University of Toronto, Toronto, ON, Canada
| | - Vivette D'Agati
- Department of Pathology, Columbia University Medical Center, New York, NY
| | - J Charles Jennette
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC
| | - Jon B Klein
- Department of Medicine, The University of Louisville School of Medicine, and Robley Rex VA Medical Center, Louisville, KY
| | | | - Katherine Twombley
- Pediatric Nephrology, Medical University of South Carolina, Charleston, SC
| | - Ronald J Falk
- Division of Nephrology and Hypertension, Kidney Center, Department of Medicine, University of North Carolina, Chapel Hill, NC
| | - Ali G Gharavi
- Division of Nephrology, Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY
| | - Brenda W Gillespie
- Department of Biostatistics, School of Public Health, University of Michigan, Ann Arbor, MI
| | - Debbie S Gipson
- Division of Nephrology, Department of Pediatrics, University of Michigan, Ann Arbor, MI
| | | | - Lawrence B Holzman
- Renal-Electrolyte and Hypertension Division, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Matthias Kretzler
- Division of Nephrology, Department of Medicine, University of Michigan, Ann Arbor, MI
| | - Bruce Robinson
- Division of Nephrology, Department of Medicine, University of Michigan, Ann Arbor, MI; Arbor Research Collaborative for Health, Ann Arbor, MI
| | - William E Smoyer
- Center for Clinical and Translational Research, The Research Institute at Nationwide Children's Hospital, Columbus, OH; Department of Pediatrics, The Ohio State University, Columbus, OH
| | - Lisa M Guay-Woodford
- Center for Translational Science, Children's National Health System, Washington, DC
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Use of genomic and functional analysis to characterize patients with steroid-resistant nephrotic syndrome. Pediatr Nephrol 2018; 33:1741-1750. [PMID: 29982877 DOI: 10.1007/s00467-018-3995-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 06/06/2018] [Accepted: 06/07/2018] [Indexed: 01/09/2023]
Abstract
BACKGROUND Children with genetic causes of steroid-resistant nephrotic syndrome (SRNS) usually do well after renal transplantation, while some with idiopathic SRNS show recurrence due to a putative podocyte-toxic factor. Distinguishing different forms of SRNS based on clinical criteria has been difficult. The aim of our study was to test a novel approach that allows categorization of patients into clinically useful subgroups. METHODS Seventeen patients with clinically confirmed SRNS were analyzed by next-generation sequencing (NGS) of 37 known SRNS genes and a functional assay of cultured human podocytes, which indirectly tests for toxicity of patients' sera by evidenced loss of podocyte focal adhesion complex (FAC) number. RESULTS We identified a pathogenic mutation in seven patients (41%). Sera from patients with monogenic SRNS caused mild loss of FAC number down to 73% compared to untreated controls, while sera from seven of the remaining ten patients with idiopathic SRNS caused significant FAC number loss to 43% (non-overlapping difference 30%, 95% CI 26-36%, P < 0.001). All patients with recurrent SRNS (n = 4) in the graft showed absence of podocyte gene mutations but significant FAC loss. Three patients had no mutation nor serum podocyte toxicity. CONCLUSIONS Our approach allowed categorization of patients into three subgroups: (1) patients with monogenic SRNS; (2) patients with idiopathic SRNS and marked serum podocyte toxicity; and (3) patients without identifiable genetic cause nor evidence of serum podocyte toxicity. Post-transplant SRNS recurrence risk appears to be low in groups 1 and 3, but high in group 2.
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Bezdíčka M, Štolbová Š, Seeman T, Cinek O, Malina M, Šimánková N, Průhová Š, Zieg J. Genetic diagnosis of steroid-resistant nephrotic syndrome in a longitudinal collection of Czech and Slovak patients: a high proportion of causative variants in NUP93. Pediatr Nephrol 2018; 33:1347-1363. [PMID: 29869118 DOI: 10.1007/s00467-018-3950-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 03/12/2018] [Accepted: 03/22/2018] [Indexed: 12/14/2022]
Abstract
BACKGROUND Steroid-resistant nephrotic syndrome (SRNS) has a heterogeneous spectrum of monogenic causes that substantially differ among populations. The aim of this study was to analyse the genetic aetiology of SRNS in Czech and Slovak paediatric patients. METHODS We analysed clinical data from 74 patients (38 boys) with congenital (15%), infant (14%), and childhood-onset (71%) SRNS collected from the Czech Republic and Slovakia from 2000 to 2017 (inclusive). The DNA samples were first analysed by Sanger sequencing (genes NPHS2, NPHS1, and WT1) and then by next generation sequencing (NGS) using a targeted panel of 48 genes previously associated with SRNS. Family segregation of the causative variants was confirmed by Sanger sequencing when possible. RESULTS Genetic diagnosis was established in 28/74 patients (38%) based on findings of pathogenic or likely pathogenic causative variants in genotypes conforming to the expected mode of inheritance. Sanger sequencing diagnosed 26% of patients, whereas second-tier testing by a targeted NGS panel diagnosed a further 12%. Frequent causative genes were NPHS2 (15%), WT1 (9.5%), and surprisingly NUP93 with four (5.4%) unrelated cases. Additional causative genes included COQ2 (two patients), NPHS1, INF2, DGKE, and LMX1B (one patient each). CONCLUSIONS Compared with outright use of NGS, our tiered genetic testing strategy was considerably more rapid and marginally less expensive. Apart from a high aetiological fraction of NPHS2 and WT1 genes, our study has identified an unexpectedly high frequency of a limited set of presumably ancestral causative mutations in NUP93. The results may aid in tailoring testing strategies in Central European populations.
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Affiliation(s)
- Martin Bezdíčka
- Department of Paediatrics, 2nd Faculty of Medicine, Charles University in Prague and University Hospital Motol, V Uvalu 84, Prague, Czech Republic
| | - Šárka Štolbová
- Department of Paediatrics, 2nd Faculty of Medicine, Charles University in Prague and University Hospital Motol, V Uvalu 84, Prague, Czech Republic
| | - Tomáš Seeman
- Department of Paediatrics, 2nd Faculty of Medicine, Charles University in Prague and University Hospital Motol, V Uvalu 84, Prague, Czech Republic
| | - Ondřej Cinek
- Department of Paediatrics, 2nd Faculty of Medicine, Charles University in Prague and University Hospital Motol, V Uvalu 84, Prague, Czech Republic.
| | - Michal Malina
- Department of Paediatrics, 2nd Faculty of Medicine, Charles University in Prague and University Hospital Motol, V Uvalu 84, Prague, Czech Republic
| | - Naděžda Šimánková
- Department of Paediatrics, 2nd Faculty of Medicine, Charles University in Prague and University Hospital Motol, V Uvalu 84, Prague, Czech Republic
| | - Štěpánka Průhová
- Department of Paediatrics, 2nd Faculty of Medicine, Charles University in Prague and University Hospital Motol, V Uvalu 84, Prague, Czech Republic
| | - Jakub Zieg
- Department of Paediatrics, 2nd Faculty of Medicine, Charles University in Prague and University Hospital Motol, V Uvalu 84, Prague, Czech Republic
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Clinical syndromes associated with Coenzyme Q10 deficiency. Essays Biochem 2018; 62:377-398. [DOI: 10.1042/ebc20170107] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 05/02/2018] [Accepted: 05/15/2018] [Indexed: 12/27/2022]
Abstract
Primary Coenzyme Q deficiencies represent a group of rare conditions caused by mutations in one of the genes required in its biosynthetic pathway at the enzymatic or regulatory level. The associated clinical manifestations are highly heterogeneous and mainly affect central and peripheral nervous system, kidney, skeletal muscle and heart. Genotype–phenotype correlations are difficult to establish, mainly because of the reduced number of patients and the large variety of symptoms. In addition, mutations in the same COQ gene can cause different clinical pictures. Here, we present an updated and comprehensive review of the clinical manifestations associated with each of the pathogenic variants causing primary CoQ deficiencies.
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Abid A, Shahid S, Shakoor M, Lanewala AA, Hashmi S, Khaliq S. Screening of the LAMB2, WT1, NPHS1, and NPHS2 Genes in Pediatric Nephrotic Syndrome. Front Genet 2018; 9:214. [PMID: 30013592 PMCID: PMC6036290 DOI: 10.3389/fgene.2018.00214] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2018] [Accepted: 05/25/2018] [Indexed: 02/04/2023] Open
Abstract
Mutations in the NPHS1, NPHS2, LAMB2, and the WT1 genes are responsible for causing nephrotic syndrome (NS) in two third of the early onset cases. This study was carried out to assess the frequencies of mutations in these genes in a cohort of pediatric NS patients. A total of 64 pediatric familial or sporadic SRNS cases were recruited. Among these, 74% had a disease onset of up to 3 years of age. We found one homozygous frameshift mutation in the NPHS1 gene in one CNS case and two homozygous mutations in the NPHS2 gene. Six mutations in four cases in the LAMB2 gene were also identified. No mutation was detected in the WT1 gene in isolated SRNS cases. LAMB2 gene missense mutations were segregating in NS cases with no extra-renal abnormalities. Analysis of the population genomic data (1000 genome and gnomAD databases) for the prevalence estimation revealed that NS is more prevalent than previously determined from clinical cohorts especially in Asian population compared with overall world populations (prevalence worldwide was 1in 189036 and in South-Asian was 1in 56689). Our results reiterated a low prevalence of mutations in the NPHS1, NPHS2, LAMB2, and WT1 genes in the studied population from Pakistan as compared to some European population that showed a high prevalence of mutations in these genes. This is a comprehensive screening of the genes causing early onset NS in sporadic and familial NS cases suggesting a more systematic and robust approach for mutation identification in all the 45 disease-causing genes in NS in our population is required.
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Affiliation(s)
- Aiysha Abid
- Centre for Human Genetics and Molecular Medicine, Sindh Institute of Urology and Transplantation, Karachi, Pakistan
| | - Saba Shahid
- Department of Genomic, National Institute of Blood Diseases, Karachi, Pakistan
| | - Madiha Shakoor
- Department of Human Genetics, University of Health Sciences, Lahore, Pakistan
| | - Ali A Lanewala
- Department of Pediatric Nephrology, Sindh Institute of Urology and Transplantation, Karachi, Pakistan
| | - Seema Hashmi
- Department of Pediatric Nephrology, Sindh Institute of Urology and Transplantation, Karachi, Pakistan
| | - Shagufta Khaliq
- Department of Human Genetics, University of Health Sciences, Lahore, Pakistan
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Stráner P, Balogh E, Schay G, Arrondel C, Mikó Á, L'Auné G, Benmerah A, Perczel A, K Menyhárd D, Antignac C, Mollet G, Tory K. C-terminal oligomerization of podocin mediates interallelic interactions. Biochim Biophys Acta Mol Basis Dis 2018; 1864:2448-2457. [PMID: 29660491 DOI: 10.1016/j.bbadis.2018.04.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2017] [Revised: 03/22/2018] [Accepted: 04/11/2018] [Indexed: 01/01/2023]
Abstract
Interallelic interactions of membrane proteins are not taken into account while evaluating the pathogenicity of sequence variants in autosomal recessive disorders. Podocin, a membrane-anchored component of the slit diaphragm, is encoded by NPHS2, the major gene mutated in hereditary podocytopathies. We formerly showed that its R229Q variant is only pathogenic when trans-associated to specific 3' mutations and suggested the causal role of an abnormal C-terminal dimerization. Here we show by FRET analysis and size exclusion chromatography that podocin oligomerization occurs exclusively through the C-terminal tail (residues 283-382): principally through the first C-terminal helical region (H1, 283-313), which forms a coiled coil as shown by circular dichroism spectroscopy, and through the 332-348 region. We show the principal role of the oligomerization sites in mediating interallelic interactions: while the monomer-forming R286Tfs*17 podocin remains membranous irrespective of the coexpressed podocin variant identity, podocin variants with an intact H1 significantly influence each other's localization (r2 = 0.68, P = 9.2 × 10-32). The dominant negative effect resulting in intracellular retention of the pathogenic F344Lfs*4-R229Q heterooligomer occurs in parallel with a reduction in the FRET efficiency, suggesting the causal role of a conformational rearrangement. On the other hand, oligomerization can also promote the membrane localization: it can prevent the endocytosis of F344Lfs*4 or F344* podocin mutants induced by C-terminal truncation. In conclusion, C-terminal oligomerization of podocin can mediate both a dominant negative effect and interallelic complementation. Interallelic interactions of NPHS2 are not restricted to the R229Q variant and have to be considered in compound heterozygous individuals.
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Affiliation(s)
- Pál Stráner
- MTA-ELTE Protein Modeling Research Group and Laboratory of Structural Chemistry and Biology, Eötvös Loránd University, Budapest, Hungary
| | - Eszter Balogh
- MTA-SE Lendület Nephrogenetic Laboratory, Budapest, Hungary; Semmelweis University, Ist Department of Pediatrics, Budapest, Hungary
| | - Gusztáv Schay
- Semmelweis University, Department of Biophysics and Radiation Biology, Budapest, Hungary
| | - Christelle Arrondel
- Laboratory of Hereditary Kidney Diseases, INSERM, UMR 1163, Imagine Institute, Paris, France; Université Paris Descartes-Sorbonne Paris Cité, Imagine Institute, Paris, France
| | - Ágnes Mikó
- MTA-SE Lendület Nephrogenetic Laboratory, Budapest, Hungary; Semmelweis University, Ist Department of Pediatrics, Budapest, Hungary
| | - Gerda L'Auné
- MTA-SE Lendület Nephrogenetic Laboratory, Budapest, Hungary; Semmelweis University, Ist Department of Pediatrics, Budapest, Hungary
| | - Alexandre Benmerah
- Laboratory of Hereditary Kidney Diseases, INSERM, UMR 1163, Imagine Institute, Paris, France; Université Paris Descartes-Sorbonne Paris Cité, Imagine Institute, Paris, France
| | - András Perczel
- MTA-ELTE Protein Modeling Research Group and Laboratory of Structural Chemistry and Biology, Eötvös Loránd University, Budapest, Hungary
| | - Dóra K Menyhárd
- MTA-ELTE Protein Modeling Research Group and Laboratory of Structural Chemistry and Biology, Eötvös Loránd University, Budapest, Hungary
| | - Corinne Antignac
- Laboratory of Hereditary Kidney Diseases, INSERM, UMR 1163, Imagine Institute, Paris, France; Université Paris Descartes-Sorbonne Paris Cité, Imagine Institute, Paris, France; Assistance Publique - Hôpitaux de Paris, Hôpital Necker-Enfants Malades, Département de Génétique, Paris, France
| | - Géraldine Mollet
- Laboratory of Hereditary Kidney Diseases, INSERM, UMR 1163, Imagine Institute, Paris, France; Université Paris Descartes-Sorbonne Paris Cité, Imagine Institute, Paris, France
| | - Kálmán Tory
- MTA-SE Lendület Nephrogenetic Laboratory, Budapest, Hungary; Semmelweis University, Ist Department of Pediatrics, Budapest, Hungary; Laboratory of Hereditary Kidney Diseases, INSERM, UMR 1163, Imagine Institute, Paris, France; Université Paris Descartes-Sorbonne Paris Cité, Imagine Institute, Paris, France.
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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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Plumb LA, Hamilton AJ, Inward CD, Ben-Shlomo Y, Caskey FJ. Continually improving standards of care: The UK Renal Registry as a translational public health tool. Pediatr Nephrol 2018; 33:373-380. [PMID: 28642999 PMCID: PMC5799353 DOI: 10.1007/s00467-017-3688-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 04/18/2017] [Accepted: 04/20/2017] [Indexed: 12/02/2022]
Abstract
A disease registry uses observational study methods to collect defined data on patients with a particular condition for a predetermined purpose. By providing comprehensive standardised data on patients with kidney disease, renal registries aim to provide a 'real world' representation of practice patterns, treatment and patient outcomes that may not be captured accurately by other methods, including randomised controlled trials. Additionally, using registries to measure variations in outcomes and audit care against standards is crucial to understanding how to improve quality of care for patients in an efficacious and cost-effective manner. Registries also have the potential to be a powerful scientific tool that can monitor and support the translational process between research and routine clinical practice, although their limitations must be borne in mind. In this review, we describe the role of the UK Renal Registry as a tool to support translational research. We describe its involvement across each stage of the translational pathway: from hypothesis generation, study design and data collection, to reporting of long-term outcomes and quality improvement initiatives. Furthermore we explore how this role may bring about improvements in care for adults and children with kidney disease.
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Affiliation(s)
- Lucy A Plumb
- The UK Renal Registry, Learning & Research Building, Southmead Hospital, Bristol, UK.
- School of Social and Community Medicine, University of Bristol, Canynge Hall, 39 Whatley Road, Bristol, BS8 2PS, UK.
| | - Alexander J Hamilton
- The UK Renal Registry, Learning & Research Building, Southmead Hospital, Bristol, UK
- School of Social and Community Medicine, University of Bristol, Canynge Hall, 39 Whatley Road, Bristol, BS8 2PS, UK
| | - Carol D Inward
- University Hospitals Bristol NHS Foundation Trust, Bristol, UK
| | - Yoav Ben-Shlomo
- The UK Renal Registry, Learning & Research Building, Southmead Hospital, Bristol, UK
- School of Social and Community Medicine, University of Bristol, Canynge Hall, 39 Whatley Road, Bristol, BS8 2PS, UK
| | - Fergus J Caskey
- The UK Renal Registry, Learning & Research Building, Southmead Hospital, Bristol, UK
- School of Social and Community Medicine, University of Bristol, Canynge Hall, 39 Whatley Road, Bristol, BS8 2PS, UK
- The Richard Bright Renal Unit, Southmead Hospital, North Bristol NHS Trust, Bristol, UK
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Abstract
Technologies such as next-generation sequencing and chromosomal microarray have advanced the understanding of the molecular pathogenesis of a variety of renal disorders. Genetic findings are increasingly used to inform the clinical management of many nephropathies, enabling targeted disease surveillance, choice of therapy, and family counselling. Genetic analysis has excellent diagnostic utility in paediatric nephrology, as illustrated by sequencing studies of patients with congenital anomalies of the kidney and urinary tract and steroid-resistant nephrotic syndrome. Although additional investigation is needed, pilot studies suggest that genetic testing can also provide similar diagnostic insight among adult patients. Reaching a genetic diagnosis first involves choosing the appropriate testing modality, as guided by the clinical presentation of the patient and the number of potential genes associated with the suspected nephropathy. Genome-wide sequencing increases diagnostic sensitivity relative to targeted panels, but holds the challenges of identifying causal variants in the vast amount of data generated and interpreting secondary findings. In order to realize the promise of genomic medicine for kidney disease, many technical, logistical, and ethical questions that accompany the implementation of genetic testing in nephrology must be addressed. The creation of evidence-based guidelines for the utilization and implementation of genetic testing in nephrology will help to translate genetic knowledge into improved clinical outcomes for patients with kidney disease.
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Affiliation(s)
- Emily E Groopman
- Division of Nephrology, Columbia University College of Physicians and Surgeons, 1150 Saint Nicholas Avenue, Russ Berrie Pavilion #412C, New York, New York 10032, USA
| | - Hila Milo Rasouly
- Division of Nephrology, Columbia University College of Physicians and Surgeons, 1150 Saint Nicholas Avenue, Russ Berrie Pavilion #412C, New York, New York 10032, USA
| | - Ali G Gharavi
- Division of Nephrology, Columbia University College of Physicians and Surgeons, 1150 Saint Nicholas Avenue, Russ Berrie Pavilion #412C, New York, New York 10032, USA
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45
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Jayasinghe K, Quinlan C, Stark Z, Patel C, Sampson MG, Saleem M, Mallett AJ. Meeting report of the 2017 KidGen Renal Genetics Symposium. Hum Genomics 2018; 12:5. [PMID: 29382385 PMCID: PMC5791341 DOI: 10.1186/s40246-018-0137-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 01/23/2018] [Indexed: 12/31/2022] Open
Abstract
The 2017 KidGen Renal Genetics Symposium was held at the Royal Children’s Hospital and Murdoch Children’s Research Institute, Melbourne, from 6 to 8 December 2017. This meeting addressed clinical, diagnostic, and research aspects of inherited kidney disease. More than 100 clinicians, researchers, and patient representatives attended the conference. The overall goal was to improve the understanding and direction of genomics in renal medicine in Australia and discuss barriers to the use of genomic testing within this area. It also aimed to strengthen collaborations between local, state, and global research and diagnostic and clinical groups.
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Affiliation(s)
- Kushani Jayasinghe
- Department of Nephrology, Monash Medical Centre, Melbourne, Australia. .,KidGen Renal Genetics Flagship, Australian Genomic Health Alliance, Melbourne, Australia.
| | - Cathy Quinlan
- KidGen Renal Genetics Flagship, Australian Genomic Health Alliance, Melbourne, Australia.,Murdoch Children's Research Institute, Melbourne, Australia.,Department of Paediatric Nephrology, Royal Children's Hospital, Melbourne, Australia
| | - Zornitza Stark
- KidGen Renal Genetics Flagship, Australian Genomic Health Alliance, Melbourne, Australia.,Murdoch Children's Research Institute, Melbourne, Australia.,Department of Pediatrics, University of Melbourne, Melbourne, Australia
| | - Chirag Patel
- KidGen Renal Genetics Flagship, Australian Genomic Health Alliance, Melbourne, Australia.,Genetic Health Queensland, Royal Brisbane and Women's Hospital, Brisbane, Australia
| | - Matthew G Sampson
- Department Of Pediatrics-Nephrology, University of Michigan School of Medicine, Ann Arbor, USA
| | - Moin Saleem
- Bristol Renal, Bristol Medical School, University of Bristol, Bristol, UK
| | - Andrew J Mallett
- KidGen Renal Genetics Flagship, Australian Genomic Health Alliance, Melbourne, Australia.,Faculty of Medicine, The University of Queensland, Brisbane, Australia.,Kidney Health Service and Conjoint Renal Research Laboratory, Royal Brisbane and Women's Hospital, Butterfield Street, Herston, Brisbane, Queensland, 4029, Australia
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46
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De Vriese AS, Sethi S, Nath KA, Glassock RJ, Fervenza FC. Differentiating Primary, Genetic, and Secondary FSGS in Adults: A Clinicopathologic Approach. J Am Soc Nephrol 2018; 29:759-774. [PMID: 29321142 DOI: 10.1681/asn.2017090958] [Citation(s) in RCA: 162] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
FSGS describes a renal histologic lesion with diverse causes and pathogenicities that are linked by podocyte injury and depletion. Subclasses of FSGS include primary, genetic, and secondary forms, the latter comprising maladaptive, viral, and drug-induced FSGS. Despite sharing certain clinical and histologic features, these subclasses differ noticeably in management and prognosis. Without an accepted nongenetic biomarker that discriminates among these FSGS types, classification of patients is often challenging. This review summarizes the clinical and histologic features, including the onset and severity of proteinuria as well as the presence of nephrotic syndrome, that may aid in identifying the specific FSGS subtype. The FSGS lesion is characterized by segmental sclerosis and must be differentiated from nonspecific focal global glomerulosclerosis. No light microscopic features are pathognomonic for a particular FSGS subcategory. The characteristics of podocyte foot process effacement on electron microscopy, while helpful in discriminating between primary and maladaptive FSGS, may be of little utility in detecting genetic forms of FSGS. When FSGS cannot be classified by clinicopathologic assessment, genetic analysis should be offered. Next generation DNA sequencing enables cost-effective screening of multiple genes simultaneously, but determining the pathogenicity of a detected genetic variant may be challenging. A more systematic evaluation of patients, as suggested herein, will likely improve therapeutic outcomes and the design of future trials in FSGS.
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Affiliation(s)
- An S De Vriese
- Division of Nephrology, AZ Sint-Jan Brugge-Oostende, Brugge, Belgium;
| | | | - Karl A Nath
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota; and
| | - Richard J Glassock
- Geffen School of Medicine at the University of California, Los Angeles, California
| | - Fernando C Fervenza
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota; and
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Trautmann A, Lipska-Ziętkiewicz BS, Schaefer F. Exploring the Clinical and Genetic Spectrum of Steroid Resistant Nephrotic Syndrome: The PodoNet Registry. Front Pediatr 2018; 6:200. [PMID: 30065916 PMCID: PMC6057105 DOI: 10.3389/fped.2018.00200] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2018] [Accepted: 06/25/2018] [Indexed: 02/05/2023] Open
Abstract
Background: Steroid resistant nephrotic syndrome (SRNS) is a rare condition, accounting for 10-15% of all children with idiopathic nephrotic syndrome. SRNS can be caused by genetic abnormalities or immune system dysfunction. The prognosis of SRNS varies from permanent remission to progression to end-stage kidney disease, and post-transplant recurrence is common. Objectives: The PodoNet registry project aims to explore the demographics and phenotypes of immune-mediated and genetic forms of childhood SRNS, to assess genotype-phenotype correlations, to evaluate clinical management and long-term outcomes, and to search for novel genetic entities and diagnostic and prognostic biomarkers in SRNS. Methods: In 2009, an international registry for SRNS was established to collect retro- and prospective information on renal and extrarenal disease manifestations, histopathological and genetic findings and information on family history, pharmacotherapy responsiveness and long-term outcomes. To date, more than 2,000 patients have been enrolled at 72 pediatric nephrology centers, constituting the largest pediatric SRNS cohort assembled to date. Results: In the course of the project, traditional Sanger sequencing was replaced by NGS-based gene panel screening covering over 30 podocyte-related genes complemented by whole exome sequencing. These approaches allowed to establish genetic diagnoses in 24% of the patients screened, widened the spectrum of genetic disease entities presenting with SRNS phenotype (COL4A3-5, CLCN5), and contributed to the discovery of new disease causing genes (MYOE1, PTPRO). Forty two percent of patients responded to intensified immunosuppression with complete or partial remission of proteinuria, whereas 58% turned out multi-drug resistant. Medication responsiveness was highly predictive of a favorable long-term outcome, whereas the diagnosis of genetic disease was associated with a high risk to develop end-stage renal disease during childhood. Genetic SRNS forms were generally resistant to immunosuppressive treatment, justifying to avoid such pharmacotherapies altogether once a genetic diagnosis is established. Even symptomatic anti-proteinuric treatment with RAS antagonists seems to be challenging and of limited efficacy in genetic forms of SRNS. The risk of post-transplant disease recurrence was around 30% in non-genetic SRNS whereas it is negligible in genetic cases. Conclusion: In summary, the PodoNet Registry has collected detailed clinical and genetic information in a large SRNS cohort and continues to generate fundamental insights regarding demographic and etiological disease aspects, genotype-phenotype associations, the efficacy of therapeutic strategies, and long-term patient and renal outcomes including post-transplant disease recurrence.
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Affiliation(s)
- Agnes Trautmann
- Division of Pediatric Nephrology, University Center for Pediatrics and Adolescent Medicine, Heidelberg, Germany
- *Correspondence: Agnes Trautmann
| | - Beata S. Lipska-Ziętkiewicz
- Clinical Genetics Unit, Department of Biology and Medical Genetics, Medical University of Gdańsk, Gdańsk, Poland
| | - Franz Schaefer
- Division of Pediatric Nephrology, University Center for Pediatrics and Adolescent Medicine, Heidelberg, Germany
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48
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Malicdan MCV, Vilboux T, Ben-Zeev B, Guo J, Eliyahu A, Pode-Shakked B, Dori A, Kakani S, Chandrasekharappa SC, Ferreira C, Shelestovich N, Marek-Yagel D, Pri-Chen H, Blatt I, Niederhuber JE, He L, Toro C, Taylor RW, Deeken J, Yardeni T, Wallace DC, Gahl WA, Anikster Y. A novel inborn error of the coenzyme Q10 biosynthesis pathway: cerebellar ataxia and static encephalomyopathy due to COQ5 C-methyltransferase deficiency. Hum Mutat 2018; 39:69-79. [PMID: 29044765 PMCID: PMC5722658 DOI: 10.1002/humu.23345] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2017] [Revised: 08/27/2017] [Accepted: 09/11/2017] [Indexed: 01/08/2023]
Abstract
Primary coenzyme Q10 (CoQ10 ; MIM# 607426) deficiencies are an emerging group of inherited mitochondrial disorders with heterogonous clinical phenotypes. Over a dozen genes are involved in the biosynthesis of CoQ10 , and mutations in several of these are associated with human disease. However, mutations in COQ5 (MIM# 616359), catalyzing the only C-methylation in the CoQ10 synthetic pathway, have not been implicated in human disease. Here, we report three female siblings of Iraqi-Jewish descent, who had varying degrees of cerebellar ataxia, encephalopathy, generalized tonic-clonic seizures, and cognitive disability. Whole-exome and subsequent whole-genome sequencing identified biallelic duplications in the COQ5 gene, leading to reduced levels of CoQ10 in peripheral white blood cells of all affected individuals and reduced CoQ10 levels in the only muscle tissue available from one affected proband. CoQ10 supplementation led to clinical improvement and increased the concentrations of CoQ10 in blood. This is the first report of primary CoQ10 deficiency caused by loss of function of COQ5, with delineation of the clinical, laboratory, histological, and molecular features, and insights regarding targeted treatment with CoQ10 supplementation.
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Affiliation(s)
- May Christine V. Malicdan
- NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, NIH and National Human Genome Research Institute, NIH, Bethesda, 20892 Maryland, USA
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, 20892 Maryland, USA
| | - Thierry Vilboux
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, 20892 Maryland, USA
- Inova Translational Medicine Institute, Falls Church, 22042 Virginia, USA
| | - Bruria Ben-Zeev
- Pediatric Neurology Unit, Edmond and Lily Safra Children’s Hospital, Sheba Medical Center, Tel-Hashomer, 5621 Israel
- Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, 69978 Israel
- Department of Pathology, Sheba Medical Center, Tel-Hashomer, 52621, Israel
| | - Jennifer Guo
- NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, NIH and National Human Genome Research Institute, NIH, Bethesda, 20892 Maryland, USA
| | - Aviva Eliyahu
- Metabolic Disease Unit, Edmond and Lily Safra Children’s Hospital, Sheba Medical Center, Tel-Hashomer, 5621 Israel
- Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, 69978 Israel
| | - Ben Pode-Shakked
- Metabolic Disease Unit, Edmond and Lily Safra Children’s Hospital, Sheba Medical Center, Tel-Hashomer, 5621 Israel
- The Dr. Pinchas Borenstein Talpiot Medical Leadership Program, Sheba Medical Center, Tel-Hashomer, 5621 Israel
- Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, 69978 Israel
| | - Amir Dori
- The Dr. Pinchas Borenstein Talpiot Medical Leadership Program, Sheba Medical Center, Tel-Hashomer, 5621 Israel
- Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, 69978 Israel
- Joseph Sagol Neuroscience Center, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, 69978 Israel
| | - Sravan Kakani
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, 20892 Maryland, USA
| | - Settara C. Chandrasekharappa
- Cancer Genetics and Comparative Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, 20892 Maryland, USA
| | - Carlos Ferreira
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, 20892 Maryland, USA
| | - Natalia Shelestovich
- Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, 69978 Israel
- Center for Mitochondrial and Epigenomic Medicine, Children’s Hospital of Philadelphia Research Institute, Philadelphia, USA
| | - Dina Marek-Yagel
- Metabolic Disease Unit, Edmond and Lily Safra Children’s Hospital, Sheba Medical Center, Tel-Hashomer, 5621 Israel
- Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, 69978 Israel
- Department of Pathology, Sheba Medical Center, Tel-Hashomer, 52621, Israel
| | - Hadass Pri-Chen
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, 20892 Maryland, USA
- The Wohl Institute for Translational Medicine, Sheba Medical Center, Tel-Hashomer, 52621, Israel
| | - Ilan Blatt
- Department of Neurology, Sheba Medical Center, Tel-Hashomer, 5621 Israel
| | - John E. Niederhuber
- Inova Translational Medicine Institute, Falls Church, 22042 Virginia, USA
- Johns Hopkins University School of Medicine, 733 North Broadway Street, Baltimore, MD, USA
| | - Langping He
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, The Medical School, Newcastle University, Newcastle upon Tyne, UK
| | - Camilo Toro
- NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, NIH and National Human Genome Research Institute, NIH, Bethesda, 20892 Maryland, USA
| | - Robert W. Taylor
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, The Medical School, Newcastle University, Newcastle upon Tyne, UK
| | - John Deeken
- Inova Translational Medicine Institute, Falls Church, 22042 Virginia, USA
| | - Tal Yardeni
- Center for Mitochondrial and Epigenomic Medicine, Children’s Hospital of Philadelphia Research Institute, Philadelphia, USA
| | - Douglas C. Wallace
- Center for Mitochondrial and Epigenomic Medicine, Children’s Hospital of Philadelphia Research Institute, Philadelphia, USA
| | - William A. Gahl
- NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, NIH and National Human Genome Research Institute, NIH, Bethesda, 20892 Maryland, USA
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, 20892 Maryland, USA
| | - Yair Anikster
- Metabolic Disease Unit, Edmond and Lily Safra Children’s Hospital, Sheba Medical Center, Tel-Hashomer, 5621 Israel
- Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, 69978 Israel
- The Wohl Institute for Translational Medicine, Sheba Medical Center, Tel-Hashomer, 52621, Israel
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49
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Feltran LS, Varela P, Silva ED, Veronez CL, Franco MC, Filho AP, Camargo MF, Koch Nogueira PC, Pesquero JB. Targeted Next-Generation Sequencing in Brazilian Children With Nephrotic Syndrome Submitted to Renal Transplant. Transplantation 2017; 101:2905-2912. [PMID: 28658201 DOI: 10.1097/tp.0000000000001846] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
BACKGROUND The aims of this study were to identify the genetic mutations profile in Brazilian children with nephrotic syndrome (NS) and to determine a genotype-phenotype correlation in this disease. METHODS Next-generation sequencing and mutation analysis were performed on 24 genes related to NS in a cross-sectional study involving 95 children who underwent kidney transplantation due to NS, excluding congenital cases. RESULTS A total of 149 variants were identified in 22 of 24 sequenced genes. The mutations were classified as pathogenic, likely pathogenic, likely benign and benign per the chance of causing the disease. NPHS2 was the most common mutated gene. We identified 8 (8.4%) patients with hereditary NS and 5 (5%) patients with probably genetically caused NS. COL4A3-5 variants were found as well, but it is not clear whether they should be considered isolated FSGS or simply a misdiagnosed type of the Alport spectrum. Considering the clinical results, hereditary NS patients presented a tendency to early disease onset when compared with the other groups (P = 0.06) and time to end stage renal disease (ESRD) was longer in this group (P = 0.03). No patients from hereditary NS group had NS recurrence after transplantation. CONCLUSIONS This is the first study in children with steroid-resistant NS who underwent kidney transplantation using next-generation sequencing. Considering our results, we believe this study has shed some light to the uncertainties of genotype-phenotype correlation in NS, where several genes cooperate to produce or even to modify the course of the disease.
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Affiliation(s)
- Luciana S Feltran
- Nephrology Department, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Patricia Varela
- Biophysics Department, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Elton Dias Silva
- Biophysics Department, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Camila Lopes Veronez
- Biophysics Department, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Maria Carmo Franco
- Nephrology Department, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Alvaro Pacheco Filho
- Nephrology Department, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Maria Fernanda Camargo
- Nephrology Department, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Paulo Cesar Koch Nogueira
- Pediatrics Department, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Joao Bosco Pesquero
- Biophysics Department, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brazil
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50
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Sen ES, Dean P, Yarram-Smith L, Bierzynska A, Woodward G, Buxton C, Dennis G, Welsh GI, Williams M, Saleem MA. Clinical genetic testing using a custom-designed steroid-resistant nephrotic syndrome gene panel: analysis and recommendations. J Med Genet 2017; 54:795-804. [PMID: 28780565 PMCID: PMC5740557 DOI: 10.1136/jmedgenet-2017-104811] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 06/27/2017] [Accepted: 06/29/2017] [Indexed: 01/16/2023]
Abstract
BACKGROUND There are many single-gene causes of steroid-resistant nephrotic syndrome (SRNS) and the list continues to grow rapidly. Prompt comprehensive diagnostic testing is key to realising the clinical benefits of a genetic diagnosis. This report describes a bespoke-designed, targeted next-generation sequencing (NGS) diagnostic gene panel assay to detect variants in 37 genes including the ability to identify copy number variants (CNVs). METHODS This study reports results of 302 patients referred for SRNS diagnostic gene panel analysis. Phenotype and clinical impact data were collected using a standard proforma. Candidate variants detected by NGS were confirmed by Sanger sequencing/Multiplex Ligation-dependent Probe Amplification with subsequent family segregation analysis where possible. RESULTS Clinical presentation was nephrotic syndrome in 267 patients and suspected Alport syndrome (AS) in 35. NGS panel testing determined a likely genetic cause of disease in 44/220 (20.0%) paediatric and 10/47 (21.3%) adult nephrotic cases, and 17/35 (48.6%) of haematuria/AS patients. Of 71 patients with genetic disease, 32 had novel pathogenic variants without a previous disease association including two with deletions of one or more exons of NPHS1 or NPHS2. CONCLUSION Gene panel testing provides a genetic diagnosis in a significant number of patients presenting with SRNS or suspected AS. It should be undertaken at an early stage of the care pathway and include the ability to detect CNVs as an emerging mechanism for genes associated with this condition. Use of clinical genetic testing after diagnosis of SRNS has the potential to stratify patients and assist decision-making regarding management.
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Affiliation(s)
- Ethan S Sen
- Bristol Renal, School of Clinical Sciences, University of Bristol, Bristol, UK
- Bristol Royal Hospital for Children, Bristol, UK
| | - Philip Dean
- Bristol Genetics Laboratory, Southmead Hospital, Bristol, UK
| | | | | | - Geoff Woodward
- Bristol Genetics Laboratory, Southmead Hospital, Bristol, UK
| | - Chris Buxton
- Bristol Genetics Laboratory, Southmead Hospital, Bristol, UK
| | - Gemma Dennis
- Bristol Genetics Laboratory, Southmead Hospital, Bristol, UK
| | - Gavin I Welsh
- Bristol Renal, School of Clinical Sciences, University of Bristol, Bristol, UK
| | - Maggie Williams
- Bristol Genetics Laboratory, Southmead Hospital, Bristol, UK
| | - Moin A Saleem
- Bristol Renal, School of Clinical Sciences, University of Bristol, Bristol, UK
- Bristol Royal Hospital for Children, Bristol, UK
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