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Ambarsari CG, Utami DAP, Tandri CC, Satari HI. Comparison of three spot proteinuria measurements for pediatric nephrotic syndrome: based on the International pediatric Nephrology Association 2022 Guidelines. Ren Fail 2023; 45:2253324. [PMID: 37724557 PMCID: PMC10512887 DOI: 10.1080/0886022x.2023.2253324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 08/24/2023] [Indexed: 09/21/2023] Open
Abstract
BACKGROUND Pediatric nephrotic syndrome (NS) requires routine proteinuria monitoring, which is costly and affects patients' quality of life. The gold-standard 24-h urine protein (UP) measurement is challenging in children, and first-morning urine collection requires specific conditions, making it difficult in outpatient settings. Studies have reported comparability of second or random morning urine sample to the first-morning specimen. This study aimed to compare outcomes of random morning proteinuria measurements to 24-h UP and the roles of the urinary protein creatinine ratio (UPCR) and dipstick tests in pediatric NS, based on International Pediatric Nephrology Association (IPNA) 2022 Guidelines. METHOD Twenty-four-hour and morning urine samples were collected from 92 pediatric NS patients. These were subjected to automated analyses for 24-h UP, UPCR, and semi-automated dipstick analysis. A blinded doctor performed manual dipstick analysis. RESULTS UPCR had a stronger correlation with 24-h UP than with automated and manual urine dipstick tests. UPCR had the highest sensitivity and specificity for predicting no remission/relapse and high sensitivity but low specificity for complete remission. The optimal UPCR cutoff for remission was 0.44 mg/mg and for no remission/relapse was 2.08 mg/mg. Automated and manual dipstick tests demonstrated limited sensitivity but high specificity and similar AUC values for remission/relapse. CONCLUSION UPCR was sensitive and specific for diagnosing no remission/relapse and sensitive but not specific for detecting remission. Manual and automated urine dipstick tests were comparable for remission and no remission/relapse detection. This study supports the IPNA 2022 Guidelines, as 2 mg/mg was the optimal UPCR cutoff for no remission/relapse, while for remission the optimal cutoff was 0.4 mg/mg.
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Affiliation(s)
- Cahyani Gita Ambarsari
- Department of Child Health, Universitas Indonesia - Cipto Mangunkusumo Hospital, Jakarta, Indonesia
- School of Medicine, University of Nottingham, Nottingham, United Kingdom
- Medical Technology Cluster, Indonesian Medical Education and Research Institute (IMERI), Universitas Indonesia, Jakarta, Indonesia
| | - Dwi Ambar Prihatining Utami
- Department of Child Health, Universitas Indonesia - Cipto Mangunkusumo Hospital, Jakarta, Indonesia
- Bina Husada Hospital (Member of Mitra Keluarga), Bogor, Indonesia
| | | | - Hindra Irawan Satari
- Department of Child Health, Universitas Indonesia - Cipto Mangunkusumo Hospital, Jakarta, Indonesia
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2
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Nandlal L, Winkler CA, Bhimma R, Cho S, Nelson GW, Haripershad S, Naicker T. Causal and putative pathogenic mutations identified in 39% of children with primary steroid-resistant nephrotic syndrome in South Africa. Eur J Pediatr 2022; 181:3595-3606. [PMID: 35920919 PMCID: PMC10673688 DOI: 10.1007/s00431-022-04581-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 07/26/2022] [Accepted: 07/26/2022] [Indexed: 11/03/2022]
Abstract
There is a paucity of data identifying genetic mutations that account for the high rate of steroid-resistant nephrotic syndrome (SRNS) in a South African paediatric population. The aim was to identify causal mutations in genes implicated in SRNS within a South African paediatric population. We enrolled 118 children with primary nephrotic syndrome (NS), 70 SRNS and 48 steroid-sensitive NS. All children with SRNS underwent kidney biopsy. We first genotyped the NPHS2 gene for the p.V260E variant in all NS cases (n = 118) and controls (n = 219). To further identify additional variants, we performed whole-exome sequencing and interrogated ten genes (NPHS1, NPHS2, WT1, LAMB2, ACTN4, TRPC6, INF2, CD2AP, PLCE1, MYO1E) implicated in SRNS with histopathological features of focal segmental glomerulosclerosis (FSGS) in 56 SRNS cases and 29 controls; we also performed exome sequencing on two patients carrying the NPHS2 p.V260E mutation as positive controls. The overall detection rate of causal and putative pathogenic mutations in children with SRNS was 27/70 (39%): 15 (21%) carried the NPHS2 p.V260E causal mutation in the homozygous state, and 12 (17%) SRNS cases carried a putative pathogenic mutation in the heterozygous state in genes (INF2 (n = 8), CD2AP (n = 3) and TRPC6 (n = 1)) known to have autosomal dominant inheritance mode. NPHS2 p.V260E homozygosity was specifically associated with biopsy-proven FSGS, accounting for 24% of children of Black ethnicity (15 of 63) with steroid-resistant FSGS. No causal or putative pathogenic mutations were identified in NPHS1, WT1, LAMB2, PLCE1, MYO1E and ACTN4. We report four novel variants in INF2, PLCE1, ACTN4 and TRPC6. Conclusion: We report putative missense variants predicted to be pathogenic in INF2, CD2AP and TRPC6 among steroid-resistant-FSGS children. However, the NPHS2 p.V260E mutation is a prevalent cause of steroid-resistant FSGS among Black South African children occurring in 24% of children with SRNS. Screening all Black African children presenting with NS for NPHS2 p.V260E will provide a precision diagnosis of steroid-resistant FSGS and inform clinical management. What is Known: • Limited data is available on the genetic disparity of SNRS in a South African paediatric setting. • The high rate of steroid resistance in Black South African children with FSGS compared to other racial groups is partially explained by the founder variant NPHS2 p.V260E. What is New: • We report putative missense variants predicted to be pathogenic in INF2, CD2AP and TRPC6 among steroid-resistant FSGS children. • NPHS2 p.V260E mutation remains a prevalent cause of steroid-resistant FSGS among Black South African children, demonstrating precision diagnostic utility.
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Affiliation(s)
- Louansha Nandlal
- Discipline of Optics and Imaging, University of KwaZulu-Natal, Durban, South Africa.
| | - Cheryl A Winkler
- Basic Research Program, Molecular Genetics Epidemiology Section, Frederick National Laboratory of the National Cancer Institute, Washington, DC, USA
| | - Rajendra Bhimma
- Department of Paediatrics and Child Health, University of KwaZulu-Natal, Durban, South Africa
| | - Sungkweon Cho
- Basic Research Program, Molecular Genetics Epidemiology Section, Frederick National Laboratory of the National Cancer Institute, Washington, DC, USA
| | - George W Nelson
- Frederick National Laboratory for Cancer Research, Frederick Advanced Biomedical Computational Science, Washington, DC, USA
| | - Sudesh Haripershad
- Department of Nephrology, University of KwaZulu-Natal, Durban, South Africa
| | - Thajasvarie Naicker
- Discipline of Optics and Imaging, University of KwaZulu-Natal, Durban, South Africa
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3
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Zhou Q, Weng Q, Zhang X, Liu Y, Tong J, Hao X, Shi H, Shen P, Ren H, Xie J, Chen N. Association Between NPHS2 p.R229Q and Focal Segmental Glomerular Sclerosis/Steroid-Resistant Nephrotic Syndrome. Front Med (Lausanne) 2022; 9:937122. [PMID: 35935761 PMCID: PMC9354893 DOI: 10.3389/fmed.2022.937122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 06/01/2022] [Indexed: 01/10/2023] Open
Abstract
Aim NPHS2 is the coding gene of podocin. This study aims to investigate the association between NPHS2 p.R229Q (rs61747728), the most frequently reported missense variant of NPHS2, and focal segmental glomerular sclerosis (FSGS) or steroid-resistant nephrotic syndrome (SRNS) based on typing the variant in a Chinese FSGS/SRNS cohort and conducting a meta-analysis. Method We recruited patients with FSGS or SRNS and healthy individuals. To conduct a meta-analysis, all studies on p.R229Q and FSGS/SRNS were searched from public databases. Results In total, we enrolled 204 patients with FSGS, 61 patients with SRNS [46 with FSGS, 9 with minimal change disease (MCD), and six patients with IgA nephropathy (IgAN)], and 100 healthy controls. Unexpectedly, p.R229Q was absent in the patients from our cohort. By meta-analysis of 21 studies including 2,489 patients with FSGS/SRNS and 6,004 healthy controls, we confirmed that the A allele of p.R229Q was significantly associated with increased risk of FSGS/SRNS (allelic OR = 1.9, 95% CI = 1.44-2.52, P < 0.001). However, the subgroup analysis showed that the association between p.R229Q and FSGS/SRNS was true only in Caucasians (allelic OR = 2.14, 95%CI = 1.54-2.98, P < 0.001) and in early-onset patients (allelic OR: 2.13, 95% CI = 1.21-3.76, P = 0.009). Conclusion NPHS2 p.R229Q may play an important role in enhancing the susceptibility of FSGS/SRNS, especially in ethnicity of Caucasian and age of early-onset patients.
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Affiliation(s)
- Qiongxiu Zhou
- Department of Nephrology, Institute of Nephrology, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- Department of Nephrology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Qinjie Weng
- Department of Nephrology, Institute of Nephrology, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Xiaoyan Zhang
- Department of Nephrology, Institute of Nephrology, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yunzi Liu
- Department of Nephrology, Institute of Nephrology, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Jun Tong
- Department of Nephrology, Institute of Nephrology, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Xu Hao
- Department of Nephrology, Institute of Nephrology, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Hao Shi
- Department of Nephrology, Institute of Nephrology, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Pingyan Shen
- Department of Nephrology, Institute of Nephrology, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Hong Ren
- Department of Nephrology, Institute of Nephrology, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Jingyuan Xie
- Department of Nephrology, Institute of Nephrology, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- *Correspondence: Jingyuan Xie,
| | - Nan Chen
- Department of Nephrology, Institute of Nephrology, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- Nan Chen,
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Spectrum of NPHS1 and NPHS2 variants in egyptian children with focal segmental glomerular sclerosis: identification of six novel variants and founder effect. Mol Genet Genomics 2022; 297:689-698. [DOI: 10.1007/s00438-022-01877-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 02/20/2022] [Indexed: 01/10/2023]
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5
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Gribouval O, Boyer O, Knebelmann B, Karras A, Dantal J, Fourrage C, Alibeu O, Hogan J, Dossier C, Tête MJ, Antignac C, Servais A. APOL1 risk genotype in European steroid-resistant nephrotic syndrome and/or focal segmental glomerulosclerosis patients of different African ancestries. Nephrol Dial Transplant 2020; 34:1885-1893. [PMID: 29992269 DOI: 10.1093/ndt/gfy176] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 05/03/2018] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Apolipoprotein L1 (APOL1) risk variants are strongly associated with sporadic focal segmental glomerulosclerosis (FSGS) in populations with African ancestry. We determined the frequency of G1/G2 variants in steroid-resistant nephrotic syndrome (SRNS)/FSGS patients with African or French West Indies ancestry in France and its relationships with other SRNS genes. METHODS In a cohort of 152 patients (139 families), the APOL1 risk variants were genotyped by direct Sanger sequencing and pathogenic mutations were screened by next-generation sequencing with a panel including 35 SRNS genes. RESULTS The two risk allele [high-risk (HR)] genotypes were found in 43.1% (66/152) of subjects compared with 18.9% (106/562) in a control population (P < 0.0001): 33 patients homozygous for APOL1 G1 alleles, 4 homozygous for G2 and 29 compound heterozygous for G1 and G2. Compared with patients in the low-risk (LR) group, patients in the HR group were more likely to originate from the French West Indies than from Africa [45/66 (68.2%) versus 30/86 (34.9%); P < 0.0001]. There were more familial cases in the HR group [27 (41.5%) versus 8 (11.4%); P < 0.0001]. However, causative mutations in monogenic SRNS genes were found in only 1 patient in the HR group compared with 16 patients (14 families) in the LR group (P = 0.0006). At diagnosis, patients in the HR group without other mutations were more often adults [35 (53.8%) versus 19 (27.1%); P = 0.003] and had a lower estimated glomerular filtration rate (78.9 versus 98.8 mL/min/1.73 m2; P = 0.02). CONCLUSIONS The HR genotype is frequent in FSGS patients with African ancestry in our cohort, especially in those originating from the West Indies, and confer a poor renal prognosis. It is usually not associated with other causative mutations in monogenic SRNS genes.
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Affiliation(s)
- Olivier Gribouval
- Inserm U1163, Institut Imagine, University Paris Descartes, Paris, France
| | - Olivia Boyer
- Inserm U1163, Institut Imagine, University Paris Descartes, Paris, France.,Pediatric Nephrology Department, Necker Hospital, APHP, Paris, France
| | - Bertrand Knebelmann
- Nephrology and Transplantation Department, Necker Hospital, APHP, Paris, France
| | - Alexandre Karras
- Nephrology Department, European Georges Pompidou Hospital, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Jacques Dantal
- Nephrology Department, Centre Hospitalier Universitaire de Nantes, Nantes, France
| | - Cécile Fourrage
- Bioinformatic Platform, Paris Descartes Sorbonne Paris Cité University, Imagine Institute, Paris, France
| | - Olivier Alibeu
- Genomic Platform, Inserm UMR1163, Paris Descartes Sorbonne Paris Cité University, Paris, France
| | - Julien Hogan
- Pediatric Nephrology Department, Robert Debré Hospital, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Claire Dossier
- Pediatric Nephrology Department, Robert Debré Hospital, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Marie Josèphe Tête
- Inserm U1163, Institut Imagine, University Paris Descartes, Paris, France
| | - Corinne Antignac
- Inserm U1163, Institut Imagine, University Paris Descartes, Paris, France.,Genetic Department, Necker Hospital, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Aude Servais
- Inserm U1163, Institut Imagine, University Paris Descartes, Paris, France.,Nephrology and Transplantation Department, Necker Hospital, APHP, Paris, France
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6
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Cheong HI. Genetic tests in children with steroid-resistant nephrotic syndrome. Kidney Res Clin Pract 2020; 39:7-16. [PMID: 32155690 PMCID: PMC7105627 DOI: 10.23876/j.krcp.20.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 02/07/2020] [Accepted: 02/19/2020] [Indexed: 11/05/2022] Open
Abstract
Steroid-resistant nephrotic syndrome (SRNS) is a common cause of chronic kidney disease in children, and a considerable number of patients progress to end-stage renal disease. SRNS is a highly heterogeneous disorder, both clinically and genetically, and more than 50 monogenic causes of SRNS, including isolated and syndromic forms, have been identified. Recent large-cohort studies indicate that at least 30% of childhood-onset SRNS cases are genetic. The benefits of definitive molecular diagnosis by genetic testing include the avoidance of unnecessary and potentially harmful diagnostic procedures (e.g., kidney biopsy) and treatment (e.g., steroid and immunosuppressants), detection of rare and potentially treatable mutations (e.g., coenzyme Q10 biosynthesis pathway defect), prediction of prognosis (e.g., posttransplant recurrence), and providing precise genetic counseling. Furthermore, the identification of novel disease-causing genes could provide new insights into the pathogenic mechanisms of SRNS. Therefore, whenever accessible and affordable, genetic testing is recommended for all pediatric patients with SRNS, and should certainly be performed in patients with a higher probability of genetic predisposition based on genotype-phenotype correlation data. The genetic testing approach should be determined for each patient, and clinicians should, therefore, be aware of the advantages and disadvantages of methods currently available, which include Sanger sequencing, gene panel testing, and whole-exome or whole-genome sequencing. Importantly, the need for precise and thorough phenotyping by clinicians, even in the era of genomics, cannot be overemphasized. This review provides an update on recent advances in genetic studies, a suggested approach for the genetic testing of pediatric patients with SRNS.
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Affiliation(s)
- Hae Il Cheong
- Department of Pediatrics, Seoul National University Children's Hospital, Seoul, Republic of Korea.,Kidney Research Institute, Medical Research Center, Seoul National University College of Medicine, Seoul, Republic of Korea
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7
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Govender MA, Fabian J, Gottlich E, Levy C, Moonsamy G, Maher H, Winkler CA, Ramsay M. The podocin V260E mutation predicts steroid resistant nephrotic syndrome in black South African children with focal segmental glomerulosclerosis. Commun Biol 2019; 2:416. [PMID: 31754646 PMCID: PMC6858321 DOI: 10.1038/s42003-019-0658-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 10/22/2019] [Indexed: 01/17/2023] Open
Abstract
In black African children with focal segmental glomerulosclerosis (FSGS) there are high rates of steroid resistance. The aim was to determine genetic associations with apolipoprotein L1 (APOL1) renal risk variants and podocin (NPHS2) variants in 30 unrelated black South African children with FSGS. Three APOL1 variants were genotyped and the exons of the NPHS2 gene sequenced in the cases and controls. APOL1 risk alleles show a modest association with steroid sensitive nephrotic syndrome (SSNS) and steroid resistant nephrotic syndrome (SRNS). The NPHS2 V260E variant was present in SRNS cases (V/V = 5; V/E = 4; E/E = 11), and was absent in SSNS cases. Haplotype analysis suggests a single mutation origin for V260E and it was associated with a decline in kidney function over a 60-month period (p = 0.026). The V260E variant is a good predictor of autosomal recessive SRNS in black South African children and could provide useful information in a clinical setting.
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Affiliation(s)
- Melanie A. Govender
- Sydney Brenner Institute for Molecular Bioscience and Division of Human Genetics, National Health Laboratory Service and School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - June Fabian
- Wits Donald Gordon Medical Centre, University of the Witwatersrand, Johannesburg, South Africa
- Division of Nephrology, Department of Internal Medicine, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Errol Gottlich
- Wits Donald Gordon Medical Centre, University of the Witwatersrand, Johannesburg, South Africa
- Department of Paediatrics, University of Pretoria, Pretoria, South Africa
| | - Cecil Levy
- Nelson Mandela Children’s Hospital, Division of Nephrology, Department of Paediatrics, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Glenda Moonsamy
- Charlotte Maxeke Johannesburg Academic Hospital, Division of Nephrology, Department of Paediatrics, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Heather Maher
- Wits Donald Gordon Medical Centre, University of the Witwatersrand, Johannesburg, South Africa
| | - Cheryl A. Winkler
- Basic Research Laboratory, Center for Cancer Research, National Cancer Institute, Leidos Biomedical Research, Inc., Frederick National Laboratory, Frederick, MD USA
| | - Michèle Ramsay
- Sydney Brenner Institute for Molecular Bioscience and Division of Human Genetics, National Health Laboratory Service and School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
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8
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Zununi Vahed S, Moghaddas Sani H, Haghi M, Mohajel Shoja M, Ardalan M. TRPC6 and NPHS2 gene variants in adult patients with steroid-resistant nephrotic syndrome in North-West of Iran. Mol Biol Rep 2019; 46:6339-6344. [PMID: 31529341 DOI: 10.1007/s11033-019-05074-1] [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: 05/08/2019] [Accepted: 09/10/2019] [Indexed: 10/26/2022]
Abstract
Podocyte gene mutations and their role in the development of nephrotic syndrome (NS) have been reported in some ethnic groups. The aim of this study was to evaluate the presence of possible variants in TRCP6 and NPHS2 (podocin) genes and their association with clinical manifestations in a group of adult patients with steroid resistant nephrotic syndrome (SRNS). All participants including 36 patients with SRNS and 71 healthy volunteers were genotyped using polymerase chain reaction (PCR) and direct sequencing. Whole exons of NPHS2 gene and -254 C > G, -218 C > T, and -361 A > T polymorphisms in the promoter of TRPC6 gene were studied. There were no significant differences in the allele and genotype frequencies of aforementioned TRCP6 polymorphisms between cases and controls (P > 0.05). However, four novel polymorphisms including - 257 T > C, - 266 G > A, - 293 G > C, and - 21 G > A found in the promoter region of TRPC6 gene that may be involved in SRNS in our cohort. In NPHS2 gene, three different polymorphisms in the NPHS2 gene were found in 7 patients with FSGS and none of the previously reported risk polymorphisms was detected in our patients. Podocin related mutations are not too much associated with SRNS in adults, but we should consider the possibility of TRPC6 gene mutation in this population.
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Affiliation(s)
| | - Hakimeh Moghaddas Sani
- Kidney Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.,School of Life and Environmental Sciences, University of Sydney, Sydney, NSW, 2006, Australia
| | - Mehdi Haghi
- Department of Biology, Faculty of Natural Sciences, University of Tabriz, Tabriz, Iran
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9
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Lim WH, Shingde M, Wong G. Recurrent and de novo Glomerulonephritis After Kidney Transplantation. Front Immunol 2019; 10:1944. [PMID: 31475005 PMCID: PMC6702954 DOI: 10.3389/fimmu.2019.01944] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 08/01/2019] [Indexed: 12/13/2022] Open
Abstract
The prevalence, pathogenesis, predictors, and natural course of patients with recurrent glomerulonephritis (GN) occurring after kidney transplantation remains incompletely understood, including whether there are differences in the outcomes and advances in the treatment options of specific GN subtypes, including those with de novo GN. Consequently, the treatment options and approaches to recurrent disease are largely extrapolated from the general population, with responses to these treatments in those with recurrent or de novo GN post-transplantation poorly described. Given a greater understanding of the pathogenesis of GN and the development of novel treatment options, it is conceivable that these advances will result in an improved structure in the future management of patients with recurrent or de novo GN. This review focuses on the incidence, genetics, characteristics, clinical course, and risk of allograft failure of patients with recurrent or de novo GN after kidney transplantation, ascertaining potential disparities between “high risk” disease subtypes of IgA nephropathy, idiopathic membranous glomerulonephritis, focal segmental glomerulosclerosis, and membranoproliferative glomerulonephritis. We will examine in detail the management of patients with high risk GN, including the pre-transplant assessment, post-transplant monitoring, and the available treatment options for disease recurrence. Given the relative paucity of data of patients with recurrent and de novo GN after kidney transplantation, a global effort in collecting comprehensive in-depth data of patients with recurrent and de novo GN as well as novel trial design to test the efficacy of specific treatment strategy in large scale multicenter randomized controlled trials are essential to address the knowledge deficiency in this disease.
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Affiliation(s)
- Wai H Lim
- Department of Renal Medicine, Sir Charles Gairdner Hospital, Perth, WA, Australia.,School of Medicine, University of Western Australia, Perth, WA, Australia
| | - Meena Shingde
- NSW Health Pathology, Institute of Clinical Pathology and Medical Research, Westmead Hospital, Westmead, NSW, Australia
| | - Germaine Wong
- Sydney School of Public Health, University of Sydney, Sydney, NSW, Australia.,Centre for Transplant and Renal Research, Westmead Hospital, Sydney, NSW, Australia.,Centre for Kidney Research, The Children's Hospital at Westmead, Sydney, NSW, Australia
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10
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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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11
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Genetic testing in steroid-resistant nephrotic syndrome: why, who, when and how? Pediatr Nephrol 2019; 34:195-210. [PMID: 29181713 PMCID: PMC6311200 DOI: 10.1007/s00467-017-3838-6] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 10/24/2017] [Accepted: 10/25/2017] [Indexed: 12/23/2022]
Abstract
Steroid-resistant nephrotic syndrome (SRNS) is a common cause of chronic kidney disease in childhood and has a significant risk of rapid progression to end-stage renal disease. The identification of over 50 monogenic causes of SRNS has revealed dysfunction in podocyte-associated proteins in the pathogenesis of proteinuria, highlighting their essential role in glomerular function. Recent technological advances in high-throughput sequencing have enabled indication-driven genetic panel testing for patients with SRNS. The availability of genetic testing, combined with the significant phenotypic variability of monogenic SRNS, poses unique challenges for clinicians when directing genetic testing. This highlights the need for clear clinical guidelines that provide a systematic approach for mutational screening in SRNS. The likelihood of identifying a causative mutation is inversely related to age at disease onset and is increased with a positive family history or the presence of extra-renal manifestations. An unequivocal molecular diagnosis could allow for a personalised treatment approach with weaning of immunosuppressive therapy, avoidance of renal biopsy and provision of accurate, well-informed genetic counselling. Identification of novel causative mutations will continue to unravel the pathogenic mechanisms of glomerular disease and provide new insights into podocyte biology and glomerular function.
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Mikó Á, K Menyhárd D, Kaposi A, Antignac C, Tory K. The mutation-dependent pathogenicity of NPHS2 p.R229Q: A guide for clinical assessment. Hum Mutat 2018; 39:1854-1860. [PMID: 30260545 DOI: 10.1002/humu.23660] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 09/24/2018] [Accepted: 09/25/2018] [Indexed: 11/08/2022]
Abstract
NPHS2, encoding podocin, is the major gene implicated in steroid-resistant nephrotic syndrome. Its c.686G>A, p.R229Q variant is the first human variant with a mutation-dependent pathogenicity; it is only pathogenic when trans-associated to specific mutations. Secondary to its high allele frequency in the European, South Asian, African, and Latino populations, its benign trans-associations can be accidentally identified in affected patients. Distinguishing pathogenic and benign p.R229Q associations can be challenging. In this paper, we present the currently known pathogenic and benign associations, and show that a rare p.R229Q association can be considered pathogenic if the variant in trans meets the following criteria; it affects the 270-351 residues and alters but does not disrupt the oligomerization, its p.R229Q association is found in a family with slowly progressing focal segmental glomerulosclerosis, but is expected to be rare in the general population (<1:106 ). We show that >15% of the p.R229Q associations identified so far in patients are benign.
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Affiliation(s)
- Ágnes Mikó
- MTA-SE Lendület Nephrogenetic Laboratory, Budapest, Hungary.,Semmelweis University, Ist Department of Pediatrics, Budapest, Hungary
| | - Dóra K Menyhárd
- MTA-ELTE Protein Modeling Research Group and Laboratory of Structural Chemistry and Biology, Eötvös Loránd University, Budapest, Hungary
| | - Ambrus Kaposi
- MTA-SE Lendület Nephrogenetic Laboratory, Budapest, Hungary
| | - Corinne Antignac
- Laboratory of Hereditary Kidney Diseases, INSERM, UMR 1163, Imagine Institute, Université Paris Descartes-Sorbonne Paris Cité, Paris, France.,Assistance Publique - Hôpitaux de Paris, Hôpital Necker-Enfants Malades, Département de Génétique, Paris, France
| | - Kálmán Tory
- MTA-SE Lendület Nephrogenetic Laboratory, Budapest, Hungary.,Semmelweis University, Ist Department of Pediatrics, Budapest, Hungary
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Wen Y, Shah S, Campbell KN. Molecular Mechanisms of Proteinuria in Focal Segmental Glomerulosclerosis. Front Med (Lausanne) 2018; 5:98. [PMID: 29713631 PMCID: PMC5912003 DOI: 10.3389/fmed.2018.00098] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2017] [Accepted: 03/26/2018] [Indexed: 01/01/2023] Open
Abstract
Focal segmental glomerulosclerosis (FSGS) is the most common primary glomerular disease resulting in end-stage renal disease in the USA and is increasing in prevalence worldwide. It is a diverse clinical entity with idiopathic, genetic, metabolic, infectious, and other causes that culminate in a characteristic histologic pattern of injury. Proteinuria is a hallmark of FSGS as well as other primary and secondary glomerular disorders. The magnitude of proteinuria at disease onset and during treatment has prognostic implications for renal survival as well as associated cardiovascular morbidity and mortality. Significant advances over the last two decades have shed light on the molecular architecture of the glomerular filtration barrier. The podocyte is the target cell for injury in FSGS. A growing list of disease-causing gene mutations encoding proteins that regulate podocyte survival and homeostasis has been identified in FSGS patients. Several pathogenic and regulatory pathways have been uncovered that result in proteinuria in rodent models and human FSGS. The recurrence of proteinuria and FSGS after kidney transplantation is supporting evidence for the role of a circulating permeability factor in disease pathogenesis. These advances reviewed herein have significant implications for disease classification and therapeutic drug development for FSGS.
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Affiliation(s)
- Yumeng Wen
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Sapna Shah
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Kirk N Campbell
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, United States
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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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15
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Lemoine S, Cochat P, Bertholet-Thomas A, Levi C, Bonnefoy C, Sellier-Leclerc AL, Bacchetta J. Néphrologie pédiatrique : que doit savoir un néphrologue d’adulte sur ces pathologies ? Nephrol Ther 2017; 13:495-504. [DOI: 10.1016/j.nephro.2017.01.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 01/31/2017] [Accepted: 01/31/2017] [Indexed: 11/25/2022]
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Ars E, Torra R. Rare diseases, rare presentations: recognizing atypical inherited kidney disease phenotypes in the age of genomics. Clin Kidney J 2017; 10:586-593. [PMID: 28980669 PMCID: PMC5622904 DOI: 10.1093/ckj/sfx051] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 05/03/2017] [Indexed: 12/11/2022] Open
Abstract
A significant percentage of adults (10%) and children (20%) on renal replacement therapy have an inherited kidney disease (IKD). The new genomic era, ushered in by the next generation sequencing techniques, has contributed to the identification of new genes and facilitated the genetic diagnosis of the highly heterogeneous IKDs. Consequently, it has also allowed the reclassification of diseases and has broadened the phenotypic spectrum of many classical IKDs. Various genetic, epigenetic and environmental factors may explain ‘atypical’ phenotypes. In this article, we examine different mechanisms that may contribute to phenotypic variability and also provide case examples that illustrate them. The aim of the article is to raise awareness, among nephrologists and geneticists, of rare presentations that IKDs may show, to facilitate diagnosis.
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Affiliation(s)
- Elisabet Ars
- Molecular Biology Laboratory, Fundació Puigvert, Instituto de Investigaciones Biomédicas Sant Pau (IIB-Sant Pau), Universitat Autònoma de Barcelona, REDinREN, Instituto de Investigación Carlos III, Barcelona, Spain
| | - Roser Torra
- Inherited Kidney Disorders, Nephrology Department, Fundació Puigvert, Instituto de Investigaciones Biomédicas Sant Pau (IIB-Sant Pau), Universitat Autònoma de Barcelona, REDinREN, Instituto de Investigación Carlos III, Barcelona, Spain
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17
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R229Q Polymorphism of NPHS2 Gene in Group of Iraqi Children with Steroid-Resistant Nephrotic Syndrome. Int J Nephrol 2017; 2017:1407506. [PMID: 28529802 PMCID: PMC5424166 DOI: 10.1155/2017/1407506] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2017] [Revised: 03/24/2017] [Accepted: 04/10/2017] [Indexed: 11/24/2022] Open
Abstract
Background. The polymorphism R229Q is one of the most commonly reported podocin sequence variations among steroid-resistant nephrotic syndromes (SRNS). Aim of the Study. We investigated the frequency and risk of this polymorphism among a group of Iraqi children with SRNS and steroid-sensitive nephrotic syndrome (SSNS). Patients and Methods. A prospective case control study which was conducted in Al-Imamein Al-Kadhimein Medical City, spanning the period from the 1st of April 2015 to 30th of November 2015. Study sample consisted of 54 children having NS, divided into 2 groups: patients group consisted of 27 children with SRNS, and control group involved 27 children with SSNS. Both were screened by real time polymerase chain reaction for R229Q in exon 5 of NPHS2 gene. Results. Molecular study showed R229Q polymorphism in 96.3% of SRNS and 100% of SSNS. There were no phenotypic or histologic characteristics of patients bearing homozygous R229Q polymorphism and the patients with heterozygous R229Q polymorphism. Conclusion. Polymorphism R229Q of NPHS2 gene is prevalent in Iraqi children with SRNS and SSNS. Further study needs to be done, for other exons and polymorphism of NPHS2 gene in those patients.
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Thomas MM, Abdel-Hamid MS, Mahfouz NN, Ghobrial EE. Genetic mutation in Egyptian children with steroid-resistant nephrotic syndrome. J Formos Med Assoc 2017; 117:48-53. [PMID: 28385484 DOI: 10.1016/j.jfma.2017.02.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 01/26/2017] [Accepted: 02/13/2017] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND/PURPOSE Nephrotic syndrome is the commonest etiology of proteinuria in children. Steroid-resistant nephrotic syndrome (SRNS) is defined by resistance to standard steroid therapy, and it continues to be one of the most intractable etiologies of renal failure. Molecular studies discovered specialized molecules in podocytes that play a role in proteinuria. Mutations in NPHS2 that encodes for podocin constitute a frequent cause of SRNS worldwide. This study aimed to screen for podocin mutations in SRNS Egyptian children and their parents. METHODS Our study included patients from 10 unrelated Egyptian families diagnosed with SRNS. Mutational analysis of the NPHS2 gene was performed by polymerase chain reaction amplification of the whole coding region of the gene and direct sequencing. RESULTS Positive consanguinity was detected in five cases, and four of them had a positive family history of SRNS in a family member. Mutational analysis of NPHS2 revealed pathogenic mutations in four cases (40%) including a novel missense in one patient (c.1A>T; p.M1L). CONCLUSION Our study concludes that mutations of NPHS2 gene are common among Egyptian children with SRNS. We support a model where ethnicity plays an important role in specific NPHS2 mutations, since a novel mutation was found in one patient in this study. Future study on a large number of Egyptian patients with SRNS is warranted to identify the actual genetic contribution of this gene in the development of SRNS in our population, which might help in patients' prognosis and management.
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Affiliation(s)
- Manal Micheal Thomas
- Human Genetics and Genome Research Division, Clinical Genetics Department, National Research Centre, Cairo, Egypt.
| | - Mohamed S Abdel-Hamid
- Medical Molecular Genetics Department and Genome Research Division, National Research Centre, Cairo, Egypt
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WT1 and NPHS2 gene mutation analysis and clinical management of steroid-resistant nephrotic syndrome. Mol Cell Biochem 2016; 426:177-181. [PMID: 27885584 DOI: 10.1007/s11010-016-2889-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2016] [Accepted: 11/15/2016] [Indexed: 01/10/2023]
Abstract
Nephrotic syndrome (NS) is a kidney disease predominantly present in children with idiopathic condition; final stage of the disease progresses into end-stage renal disease. Generally, NS is treated using standard steroid therapy, however; most of the children are steroid sensitive and about 15-20% are non-responders (SRNS). Non-responsiveness of these children would be a risk with the possibility of mutational changes in podocyte genes (NPHS1, NPHS2, WT1, PLCE1). The mutation in podocyte genes is associated with SRNS. NPHS1, NPHS2, and WT1 genes are identified/directly linked to SRNS. The present study is a surveillance on the mutation analysis of WT1 (exons 8 and 9) and NPHS2 (exons 1-8) gene in SRNS followed by clinical management. In the present study, we analyzed these two genes in a total of 117 SRNS (73 boys and 44 girls) children. A total of five mutations were detected in six children. First, WT1 mutation was detected at 9th intron-IVS 9 + 4C > T position in one SRNS female patient. This WT1 mutation was identified in a girl having Frasier Syndrome (FS) with focal segmental glomerulosclerosis and a complete sex reversal found through molecular and karyological screening. In NPHS2, missense mutations of P20L (in two children), P316S, and p.R229Q, and a frame shift mutation of 42delG were detected. Thus, applying molecular investigation helped us to decide on treatment plan of SRNS patients, mainly to avoid unnecessary immunosuppressive treatment.
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Hoefele J, Kemper MJ, Schoenermarck U, Mueller S, Klein HG, Lemke A. Truncating Wilms Tumor Suppressor Gene 1 Mutation in an XX Female with Adult-Onset Focal Segmental Glomerulosclerosis and Streak Ovaries: A Case Report. Nephron Clin Pract 2016; 135:72-76. [PMID: 27701157 DOI: 10.1159/000450709] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 09/01/2016] [Indexed: 11/19/2022] Open
Abstract
About 30% of children with nephrotic syndrome (NS) have inherited forms. Among them, mutations in Wilms tumor suppressor gene 1 (WT1) are a well characterized cause associated with steroid-resistant NS, Wilms tumor, and urogenital malformation in males. However, the role of WT1 mutations in adult-onset focal segmental glomerulosclerosis (FSGS) is unclear. We report the case of a 38-year-old female with FSGS. She had been diagnosed with streak ovaries during diagnostic workup for infertility. Mutational analysis identified the heterozygous mutation c.1372C>T (p.Arg458*) in WT1 and the heterozygous non-neutral polymorphism c.868G>A (p.Arg229Gln) in NPHS2. Chromosomal analysis revealed a normal 46,XX female karyotype. Our case highlights that WT1 mutations should be considered in XX females with adult-onset FSGS, especially if urogenital abnormalities are present.
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Affiliation(s)
- Julia Hoefele
- Institute of Human Genetics, Technical University Munich, Munich, Germany
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21
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Novel NPHS2 variant in patients with familial steroid-resistant nephrotic syndrome with early onset, slow progression and dominant inheritance pattern. Clin Exp Nephrol 2016; 21:677-684. [DOI: 10.1007/s10157-016-1331-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 08/22/2016] [Indexed: 12/01/2022]
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Recurrence and Treatment after Renal Transplantation in Children with FSGS. BIOMED RESEARCH INTERNATIONAL 2016; 2016:6832971. [PMID: 27213154 PMCID: PMC4860214 DOI: 10.1155/2016/6832971] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/25/2015] [Revised: 03/14/2016] [Accepted: 04/04/2016] [Indexed: 01/15/2023]
Abstract
Focal segmental glomerulosclerosis (FSGS) is a common cause of end-stage renal disease and a common pathologic diagnosis of idiopathic nephrotic syndrome (NS), especially in steroid-resistant cases. FSGS is known to recur after kidney transplantation, frequently followed by graft loss. However, not all patients with FSGS suffer from recurrence after kidney transplantation, and genetic and secondary FSGS have a negligible risk of recurrence. Furthermore, many cases of recurrence achieve remission with the current management of recurrence (intensive plasmapheresis/immunosuppression, including rituximab), and other promising agents are being evaluated. Therefore, a pathologic diagnosis of FSGS itself should not cause postponement of allograft kidney transplantation. For patients with a high risk of recurrence who presented with classical symptoms of NS, that is, severe edema, proteinuria, and hypoalbuminemia, close monitoring of proteinuria is necessary, followed by immediate, intensive treatment for recurrence.
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[NPHS2 Mutation analysis study in children with steroid-resistant nephrotic syndrome]. ACTA ACUST UNITED AC 2015; 87:31-6. [PMID: 26455708 DOI: 10.1016/j.rchipe.2015.06.025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2015] [Accepted: 06/15/2015] [Indexed: 11/23/2022]
Abstract
UNLABELLED Podocin is a protein located in the glomerular slit diaphragm where it takes part in the regulation of glomerular filtration. Mutations of the NPHS2 gene that codes podocin are the main cause of autosomal recessive steroid resistant nephrotic syndrome (SRNS). OBJECTIVES To identify the NPHS2 mutations in Chilean children with SRNS, and to determine the prevalence of the most common variants in a group of healthy adults. PATIENTS AND METHODS Mutation analysis of NPHS2 in 34 Chilean children with SRNS. Once the two most common variants of NPHS2 were identified, screening for these mutations was performed on 233 healthy adults. The mutation analysis was performed by the direct sequencing of the eight coding exons by polymerase chain reaction amplification. The DNA sequencing was performed using a fluorometric method, and then evaluated with SeqPilot software. The relationship between the presence of NPHS2 variants and SRNS was calculated by comparing the allele frequency between patients with SRNS and those of the healthy volunteers using the exact Fisher test. A P<.05 was considered significant. RESULTS Pathogenic NPHS2 mutations were detected in 7 (21%) of the 34 patients studied, of which 6 were heterozygotes for p.R229Q and p.A284V. The presence of p.R229Q was 2.46% in the healthy volunteers. CONCLUSIONS This study shows that p.R229Q and p.A284V are the most frequent variants in Chilean children with SRNS. It is the first time that this relationship has been reported in Chilean children. Based on this, a screening strategy is proposed for the genetic study in patients with SRNS and their families. A parallel or sequential search strategy for p.R229Q and p.A284V in these patients is proposed.
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25
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Klaassen I, Özgören B, Sadowski CE, Möller K, van Husen M, Lehnhardt A, Timmermann K, Freudenberg F, Helmchen U, Oh J, Kemper MJ. Response to cyclosporine in steroid-resistant nephrotic syndrome: discontinuation is possible. Pediatr Nephrol 2015; 30:1477-83. [PMID: 25903641 DOI: 10.1007/s00467-015-3109-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Revised: 03/11/2015] [Accepted: 03/25/2015] [Indexed: 10/23/2022]
Abstract
BACKGROUND Steroid-resistant nephrotic syndrome (SRNS) is still regarded as a serious disease although treatment with cyclosporine (CSA) has improved outcome. However, the duration of treatment in responders is unclear, and treatment of patients with genetic causes is a matter of debate. METHODS Thirty-six patients with SRNS were studied retrospectively. Median age at presentation was 3.2 (range, 0.06-15.0) and median follow-up 15.5 years (range, 1.8-27.7), respectively; 23 (64%) had focal segmental glomerulosclerosis (FSGS) on biopsy. In 33/36 patients (92%), genetic testing was performed for at least three most common genes known to be mutated in SRNS. RESULTS Nineteen patients (53%), especially those with minimal change nephrotic syndrome (MCNS) at initial biopsy (p < 0.002), entered complete remission with CSA monotherapy, including one patient with compound heterozygous NPHS1 and dominant ACTN4 mutation, respectively. Ten patients entered partial remission (28%, all FSGS), including two with NPHS2 mutations. Seven patients (six FSGS, one MCNS) did not respond to treatment. In 15 of 19 responders to CSA, treatment was stopped after a median of 3.1 years (range, 0.5-14) and no further relapses occurred in 11/15 (73%) patients with median follow-up of 9.7 years. CONCLUSIONS CSA monotherapy is effective in SRNS. Discontinuation of CSA is possible in many patients with complete remission.
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Affiliation(s)
- Ilka Klaassen
- Pediatric Nephrology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
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Lu L, Sun XM, Yin Y, Huang YF, Wang M, Wan H, Wei LB, Xiao W. The amino acid mutations of the podocin in proteinuria: a meta-analysis. Ren Fail 2015. [PMID: 26211502 DOI: 10.3109/0886022x.2015.1067129] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
While many previous studies have reported an association between the single-nucleotide polymorphisms (SNPs) of the podocin and proteinuria occurred, a conclusive relationship has not been defined in every oligoallelic state of amino acid (AA) mutations in podocin. In this study, we performed a meta-analysis of the published data to investigate the impact of the oligoallelic AA mutations of the podocin on proteinuria; a total 16 AA mutations were investigated for oligoallelic pathogenicity. Despite significant heterogeneity within some of the comparisons, the results revealed significantly higher risks of proteinuria in early-onset (onset age <16) individuals for five mutations (P118L, R138Q, R168H, V180M, and V260E), and in all onset ages individuals for five mutations (R138Q, G140X, R229Q, V260E, and V290M) compared to non-variant individuals. We also tested the steroid response in individuals with R229Q and E237Q. No statistically significant differences in the two mutations carrier rate were observed between steroid resistance patients and controls. No AA mutation was selected for meta-analysis on the recurrence of proteinuria after renal transplantation as lack of control data. In conclusion, our meta-analysis tested the pathogenicity of the oligoallelic AA mutations in podocin and suggested the potential causative mutations, and the alleles showing an association with protein susceptibility. The sensitivity and specificity of each causative mutation are pending further testing.
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Affiliation(s)
- Lu Lu
- a School of Traditional Chinese Medicine, Southern Medical University , Guangzhou , China
| | - Xiao-ming Sun
- a School of Traditional Chinese Medicine, Southern Medical University , Guangzhou , China
| | - Yi Yin
- a School of Traditional Chinese Medicine, Southern Medical University , Guangzhou , China .,b Department of Nephrology , Southern Medical University TCM-Integrated Hospital , Guangzhou , China .,c Department of Traditional Chinese Medicine , ZhuJiang Hospital, Southern Medical University , Guangzhou , China , and
| | - Yan-feng Huang
- a School of Traditional Chinese Medicine, Southern Medical University , Guangzhou , China .,b Department of Nephrology , Southern Medical University TCM-Integrated Hospital , Guangzhou , China
| | - Ming Wang
- c Department of Traditional Chinese Medicine , ZhuJiang Hospital, Southern Medical University , Guangzhou , China , and
| | - Heng Wan
- d Department of Endocrinology , The Third Affiliated Hospital, Southern Medical University , Guangzhou , China
| | - Lian-Bo Wei
- a School of Traditional Chinese Medicine, Southern Medical University , Guangzhou , China .,b Department of Nephrology , Southern Medical University TCM-Integrated Hospital , Guangzhou , China .,c Department of Traditional Chinese Medicine , ZhuJiang Hospital, Southern Medical University , Guangzhou , China , and
| | - Wei Xiao
- a School of Traditional Chinese Medicine, Southern Medical University , Guangzhou , China
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Phelan PJ, Hall G, Wigfall D, Foreman J, Nagaraj S, Malone AF, Winn MP, Howell DN, Gbadegesin R. Variability in phenotype induced by the podocin variant R229Q plus a single pathogenic mutation. Clin Kidney J 2015; 8:538-42. [PMID: 26413278 PMCID: PMC4581382 DOI: 10.1093/ckj/sfv063] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 06/29/2015] [Indexed: 01/23/2023] Open
Abstract
Background Mutations in podocin (NPHS2) are the most common cause of childhood onset autosomal recessive steroid-resistant nephrotic syndrome (SRNS). The disease is characterized by early-onset proteinuria, resistance to immunosuppressive therapy and rapid progression to end-stage renal disease. Compound heterozygous changes involving the podocin variant R229Q combined with another pathogenic mutation have been associated with a mild phenotype with disease onset often in adulthood. Methods We screened 19 families with early-onset SRNS for mutations in NPHS2 and WT1 and identified four disease-causing mutations (three in NPHS2 and one in WT1) prior to planned whole-exome sequencing. Results We describe two families with three individuals presenting in childhood who are compound heterozygous for R229Q and one other pathogenic NPHS2 mutation, either L327F or A297V. One child presented at age 4 years (A297V plus R229Q) and the other two at age 13 (L327F plus R229Q), one with steadily deteriorating renal function. Conclusions These cases highlight the phenotypic variability associated with the NPHS2 R229Q variant plus pathogenic mutation. Individuals may present with early aggressive disease.
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Affiliation(s)
- Paul J Phelan
- Duke Molecular Physiology Institute , Duke University , Durham, NC , USA ; Division of Nephrology, Department of Medicine , Duke University Medical Center , Durham, NC , USA ; Department of Nephrology , Royal Infirmary of Edinburgh, NHS Lothian , Edinburgh , UK
| | - Gentzon Hall
- Duke Molecular Physiology Institute , Duke University , Durham, NC , USA ; Division of Nephrology, Department of Medicine , Duke University Medical Center , Durham, NC , USA
| | - Delbert Wigfall
- Department of Nephrology , Royal Infirmary of Edinburgh, NHS Lothian , Edinburgh , UK
| | - John Foreman
- Department of Nephrology , Royal Infirmary of Edinburgh, NHS Lothian , Edinburgh , UK
| | - Shashi Nagaraj
- Department of Nephrology , Royal Infirmary of Edinburgh, NHS Lothian , Edinburgh , UK
| | - Andrew F Malone
- Duke Molecular Physiology Institute , Duke University , Durham, NC , USA ; Division of Nephrology, Department of Medicine , Duke University Medical Center , Durham, NC , USA
| | - Michelle P Winn
- Duke Molecular Physiology Institute , Duke University , Durham, NC , USA ; Division of Nephrology, Department of Medicine , Duke University Medical Center , Durham, NC , USA
| | - David N Howell
- Department of Pathology , Duke University Medical Center , Durham, NC , USA
| | - Rasheed Gbadegesin
- Duke Molecular Physiology Institute , Duke University , Durham, NC , USA ; Department of Pediatrics , Duke University Medical Center , Durham, NC , USA
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Stefanou C, Pieri M, Savva I, Georgiou G, Pierides A, Voskarides K, Deltas C. Co-Inheritance of Functional Podocin Variants with Heterozygous Collagen IV Mutations Predisposes to Renal Failure. Nephron Clin Pract 2015; 130:200-12. [PMID: 26138234 DOI: 10.1159/000432406] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Accepted: 05/16/2015] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS A subset of patients who present with proteinuria and are diagnosed with focal segmental glomerulosclerosis (FSGS) have inherited heterozygous COL4A3/A4 mutations and are also diagnosed with thin basement membrane nephropathy (TBMN-OMIM: 141200). Two studies showed that co-inheritance of NPHS2-p.Arg229Gln, a podocin variant, may increase the risk for proteinuria and renal function decline. METHODS We hypothesized that additional podocin variants may exert a similar effect. We studied genetically a well-characterized Cypriot TBMN patient cohort by re-sequencing the NPHS2 coding region. We also performed functional studies in cell culture experiments, investigating the interaction of podocin variants with itself and with nephrin. RESULTS Potentially disease-modifying podocin variants were searched for by analyzing NPHS2 in 35 'severe' TBMN patients. One non-synonymous variant, p.Glu237Gln, was detected. Both variants, p.Arg229Gln and p.Glu237Gln, were tested in a larger cohort of 122 TBMN patients, who were categorized as 'mild' or 'severe' based on the presence of microscopic hematuria alone or combined with chronic renal failure and/or proteinuria. Seven 'severe' patients carried either of the 2 variants; none was present in the 'mild' patients (p = 0.05, Pearson χ(2)). The 7 carriers belong in 2 families segregating mutation COL4A3-p.Gly1334Glu. Inheritance of the wild-type (WT) and mutant alleles correlated with the phenotype (combined concordance probability 0.003). Immunofluorescence (IF) experiments after dual co-transfection of WT and mutant podocin suggested altered co-localization of mutant homodimers. IF experiments after co-transfection of WT podocin and nephrin showed normal membrane localization, while both podocin variants interfered with normal trafficking, demonstrating perinuclear staining. Immunoprecipitation experiments showed stronger binding of mutant podocin to WT podocin or nephrin. CONCLUSION The results support the hypothesis that certain hypomorphic podocin variants may act as adverse genetic modifiers when co-inherited with COL4A3/A4 mutations, thus predisposing to FSGS and severe kidney function decline.
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Affiliation(s)
- Charalambos Stefanou
- Molecular Medicine Research Center and Laboratory of Molecular and Medical Genetics, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus
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Ng KH, Heng CK, Khor CC, Yap HK. Genes in FSGS: Diagnostic and Management Strategies in Children. CURRENT PEDIATRICS REPORTS 2015. [DOI: 10.1007/s40124-014-0064-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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30
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Bińczak-Kuleta A, Rubik J, Litwin M, Ryder M, Lewandowska K, Taryma-Leśniak O, Clark JS, Grenda R, Ciechanowicz A. Retrospective mutational analysis of NPHS1, NPHS2, WT1 and LAMB2 in children with steroid-resistant focal segmental glomerulosclerosis - a single-centre experience. Bosn J Basic Med Sci 2015; 14:89-93. [PMID: 24856380 DOI: 10.17305/bjbms.2014.2270] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The aim of our study was to examine NPHS1, NPHS2, WT1 and LAMB2 mutations, previously reported in two thirds of patients with nephrotic syndrome with onset before the age of one year old. Genomic DNA samples from Polish children (n=33) with Steroid-Resistant Nephrotic Syndrome (SRNS) due to focal segmental glomerulosclerosis (FSGS), manifesting before the age of 13 years old, underwent retrospective analysis of NPHS1, NPHS2, WT1 (exons 8, 9 and adjacent exon/intron boundaries) and LAMB2. No pathogenic NPHS1 or LAMB2 mutations were found in our FSGS cohort. SRNS-causing mutations of NPHS2 and WT1 were detected in 7 of 33 patients (21%), including those with nephrotic syndrome manifesting before one year old: five of seven patients. Four patients had homozygous c.413G>A (p.Arg138Gln) NPHS2 mutations; one subject was homozygous for c.868G>A (p.Val290Met) NPHS2. A phenotypic female had C>T transition at position +4 of the WT1 intron 9 (c.1432+4C>T) splice-donor site, and another phenotypic female was heterozygous for G>A transition at position +5 (c.1432+5G>A). Genotyping revealed a female genotypic gender (46, XX) for the first subject and male (46, XY) for the latter. In addition, one patient was heterozygous for c.104dup (p.Arg36Profs*34) NPHS2; two patients carried a c.686G>A (p.Arg229Gln) NPHS2 non-neutral variant. Results indicate possible clustering of causative NPHS2 mutations in FSGS-proven SRNS with onset before age one year old, and provide additional evidence that patients with childhood steroid-resistant nephrotic syndrome due to focal segmental glomerulosclerosis should first undergo analysis of NPHS2 coding sequence and WT1 exons 8 and 9 and surrounding exon/intron boundary sequences, followed by gender genotyping.
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Affiliation(s)
- Agnieszka Bińczak-Kuleta
- Department of Clinical and Molecular Biochemistry, Pomeranian Medical University, al. Powstańców Wlkp. 72, 70-111 Szczecin, Poland
| | - Jacek Rubik
- Department of Nephrology, Kidney Transplantation and Hypertension, Children`s Memorial Health Institute, Al. Dzieci Polskich 20, 04-730 Warsaw, Poland
| | - Mieczysław Litwin
- Department of Nephrology, Kidney Transplantation and Hypertension, Children`s Memorial Health Institute, Al. Dzieci Polskich 20, 04-730 Warsaw, Poland
| | - Małgorzata Ryder
- Department of Clinical and Molecular Biochemistry, Pomeranian Medical University, al. Powstańców Wlkp. 72, 70-111 Szczecin, Poland
| | - Klaudyna Lewandowska
- Department of Clinical and Molecular Biochemistry, Pomeranian Medical University, al. Powstańców Wlkp. 72, 70-111 Szczecin, Poland
| | - Olga Taryma-Leśniak
- Department of Clinical and Molecular Biochemistry, Pomeranian Medical University, al. Powstańców Wlkp. 72, 70-111 Szczecin, Poland
| | - Jeremy S Clark
- Department of Clinical and Molecular Biochemistry, Pomeranian Medical University, al. Powstańców Wlkp. 72, 70-111 Szczecin, Poland
| | - Ryszard Grenda
- Department of Nephrology, Kidney Transplantation and Hypertension, Children`s Memorial Health Institute, Al. Dzieci Polskich 20, 04-730 Warsaw, Poland
| | - Andrzej Ciechanowicz
- Department of Clinical and Molecular Biochemistry, Pomeranian Medical University, al. Powstańców Wlkp. 72, 70-111 Szczecin, Poland
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Bullich G, Trujillano D, Santín S, Ossowski S, Mendizábal S, Fraga G, Madrid Á, Ariceta G, Ballarín J, Torra R, Estivill X, Ars E. Targeted next-generation sequencing in steroid-resistant nephrotic syndrome: mutations in multiple glomerular genes may influence disease severity. Eur J Hum Genet 2014; 23:1192-9. [PMID: 25407002 PMCID: PMC4538209 DOI: 10.1038/ejhg.2014.252] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Revised: 10/14/2014] [Accepted: 10/16/2014] [Indexed: 01/26/2023] Open
Abstract
Genetic diagnosis of steroid-resistant nephrotic syndrome (SRNS) using Sanger sequencing is complicated by the high genetic heterogeneity and phenotypic variability of this disease. We aimed to improve the genetic diagnosis of SRNS by simultaneously sequencing 26 glomerular genes using massive parallel sequencing and to study whether mutations in multiple genes increase disease severity. High-throughput mutation analysis was performed in 50 SRNS and/or focal segmental glomerulosclerosis (FSGS) patients, a validation cohort of 25 patients with known pathogenic mutations, and a discovery cohort of 25 uncharacterized patients with probable genetic etiology. In the validation cohort, we identified the 42 previously known pathogenic mutations across NPHS1, NPHS2, WT1, TRPC6, and INF2 genes. In the discovery cohort, disease-causing mutations in SRNS/FSGS genes were found in nine patients. We detected three patients with mutations in an SRNS/FSGS gene and COL4A3. Two of them were familial cases and presented a more severe phenotype than family members with mutation in only one gene. In conclusion, our results show that massive parallel sequencing is feasible and robust for genetic diagnosis of SRNS/FSGS. Our results indicate that patients carrying mutations in an SRNS/FSGS gene and also in COL4A3 gene have increased disease severity.
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Affiliation(s)
- Gemma Bullich
- 1] Molecular Biology Laboratory, Fundació Puigvert, Instituto de Investigaciones Biomédicas Sant Pau (IIB-Sant Pau), Universitat Autònoma de Barcelona, REDinREN, Instituto de Investigación Carlos III, Barcelona, Catalonia, Spain [2] Nephrology Department, Fundació Puigvert, Instituto de Investigaciones Biomédicas Sant Pau (IIB-Sant Pau), Universitat Autònoma de Barcelona, REDinREN, Instituto de Investigación Carlos III, Barcelona, Catalonia, Spain
| | - Daniel Trujillano
- 1] Genomics and Disease Group, Bioinformatics and Genomics Programme, Centre for Genomic Regulation (CRG), Barcelona, Catalonia, Spain [2] Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona, Catalonia, Spain [3] Hospital del Mar Medical Research Institute (IMIM), Barcelona, Catalonia, Spain [4] CIBER in Epidemiology and Public Health (CIBERESP), Barcelona, Catalonia, Spain
| | - Sheila Santín
- Molecular Biology Laboratory, Fundació Puigvert, Instituto de Investigaciones Biomédicas Sant Pau (IIB-Sant Pau), Universitat Autònoma de Barcelona, REDinREN, Instituto de Investigación Carlos III, Barcelona, Catalonia, Spain
| | - Stephan Ossowski
- 1] Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona, Catalonia, Spain [2] Genomic and Epigenomic Variation in Disease Group, Centre for Genomic Regulation (CRG), Barcelona, Catalonia, Spain
| | - Santiago Mendizábal
- Pediatric Nephrology Department, Hospital Universitario La Fe, Valencia, Spain
| | - Gloria Fraga
- Pediatric Nephrology Department, Hospital de la Santa Creu i Sant Pau, Barcelona, Catalonia, Spain
| | - Álvaro Madrid
- Pediatric Nephrology Department, Hospital Vall d'Hebron, Barcelona, Spain
| | - Gema Ariceta
- Pediatric Nephrology Department, Hospital Vall d'Hebron, Barcelona, Spain
| | - José Ballarín
- Nephrology Department, Fundació Puigvert, Instituto de Investigaciones Biomédicas Sant Pau (IIB-Sant Pau), Universitat Autònoma de Barcelona, REDinREN, Instituto de Investigación Carlos III, Barcelona, Catalonia, Spain
| | - Roser Torra
- Nephrology Department, Fundació Puigvert, Instituto de Investigaciones Biomédicas Sant Pau (IIB-Sant Pau), Universitat Autònoma de Barcelona, REDinREN, Instituto de Investigación Carlos III, Barcelona, Catalonia, Spain
| | - Xavier Estivill
- 1] Genomics and Disease Group, Bioinformatics and Genomics Programme, Centre for Genomic Regulation (CRG), Barcelona, Catalonia, Spain [2] Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona, Catalonia, Spain [3] Hospital del Mar Medical Research Institute (IMIM), Barcelona, Catalonia, Spain [4] CIBER in Epidemiology and Public Health (CIBERESP), Barcelona, Catalonia, Spain
| | - Elisabet Ars
- 1] Molecular Biology Laboratory, Fundació Puigvert, Instituto de Investigaciones Biomédicas Sant Pau (IIB-Sant Pau), Universitat Autònoma de Barcelona, REDinREN, Instituto de Investigación Carlos III, Barcelona, Catalonia, Spain [2] Nephrology Department, Fundació Puigvert, Instituto de Investigaciones Biomédicas Sant Pau (IIB-Sant Pau), Universitat Autònoma de Barcelona, REDinREN, Instituto de Investigación Carlos III, Barcelona, Catalonia, Spain
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32
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Pollak MR. Familial FSGS. Adv Chronic Kidney Dis 2014; 21:422-5. [PMID: 25168831 DOI: 10.1053/j.ackd.2014.06.001] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Revised: 05/31/2014] [Accepted: 06/02/2014] [Indexed: 12/12/2022]
Abstract
Focal segmental glomerulosclerosis (FSGS) and nephrotic syndrome can be caused by rare highly penetrant mutations in number of genes. FSGS can follow both recessive and dominant inheritance patterns. In general, recessive forms present early, whereas the autosomal dominant forms present in adolescence or adulthood. Many of the genes found to be mutated in FSGS and nephrotic syndrome patients encode proteins essential for normal podocyte structure and/or function. An exception appears to be APOL1, which harbors common variants responsible for the high rate of FSGS and other nephropathies in people of recent African ancestry. Familial FSGS should be regarded as part of a spectrum of inherited glomerulopathies where the precise histologic presentation may depend on the age of onset, function of the responsible gene and gene products, and other factors.
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Turgutalp K, Kıykım A, Bardak S, Demir S, Karabulut Ü, Özcan T, Helvacı I, Gözükara Y. Is the red cell distribution width strong predictor for treatment response in primary glomerulonephritides? Ren Fail 2014; 36:1083-9. [PMID: 24932664 DOI: 10.3109/0886022x.2014.926771] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Novel biomarkers are needed to predict the response to treatment in patients with nephrotic syndrome (NS) due to primary glomerulonephritides (PGN). We aimed to test the predictive value of red blood cell distribution width (RDW) for estimation of response to therapy in adult patients with NS. Study design, setting & participants, and intervention: We performed a prospective study including 176 patients with NS due to PGN. Patients were divided into three groups according to their response to the treatment. Group 1 was composed of patients with complete remission whereas group 2 was composed of patients with partial remission and group 3 was composed of patients who were resistant to the treatment. RESULTS The highest baseline mean RDW value was found in group 3 patients (17.8 ± 1.8) whereas the lowest in group 1 (13.4 ± 0.7) before treatment (p<0.05). We found a significant decrease in RDW value after an effective treatment in groups 1 and group 2 (p<0.05). However, there was no significant change in RDW values after treatment in group 3 (p>0.05). Most of the patient with complete remission had base-line RDW level ≤ 14% (n=45, 90%) (p<0.001, Kendal Tau: -0.86), and most of the patients who were resistant to the treatment had base-line RDW level p>15% (n=68, 86.1%) (p<0.001, Kendal Tau: -0.87). CONCLUSION Our results suggest that pre-treatment RDW value is a promising novel biomarker for predicting response to the treatment in adult patients with NS due to PGN.
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Affiliation(s)
- Kenan Turgutalp
- Department of Internal Medicine, Division of Nephrology, Mersin University , Mersin , Turkey
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Lee SE, Min SI, Kim YS, Ha J, Ha IS, Cheong HI, Kim SJ, Choi Y, Kang HG. Recurrence of idiopathic focal segmental glomerulosclerosis after kidney transplantation: experience of a Korean tertiary center. Pediatr Transplant 2014; 18:369-76. [PMID: 24802343 DOI: 10.1111/petr.12257] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/24/2014] [Indexed: 11/29/2022]
Abstract
FSGS is the second most common cause of idiopathic NS in children. It often progresses to ESRD and commonly recurs after KT. To investigate the risk factors and the prognosis of recurrence in pediatric idiopathic FSGS in Korea, retrospective review of 43 KT in 38 children with idiopathic FSGS of last two decades was conducted. The patients presented at the median age of 5.1 yr (range 1.1-13.8 yr) and received KT 5.7 yr later (range 1.3-17.6 yr). FSGS recurred in 20 allografts immediately after transplantation, only in those who presented with NS but not in those who presented with AUA. The risk factors for recurrence were age of onset >5 yr and progression to ESRD within six yr but not sooner than 18 months. CR was achieved in 13 patients with FSGS recurrence and sustained in nine without subsequent relapse over a median of six and a half yr (0.6-20.7 yr). Pediatric idiopathic FSGS presenting with NS recurred in more than half of patients after transplantation. Interestingly, more rapid progression within less than 18 months did not predict recurrence. To identify high-risk patients of recurrence, an international cooperative study would be necessary.
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Affiliation(s)
- Se Eun Lee
- Department of Pediatrics, Seoul National University College of Medicine and Research Center for Rare Diseases, Seoul, Korea
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35
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Lu L, Wan H, Yin Y, Feng WJ, Wang M, Zou YC, Huang B, Wang DT, Shi Y, Zhao Y, Wei LB. The p.R229Q variant of the NPHS2 (podocin) gene in focal segmental glomerulosclerosis and steroid-resistant nephrotic syndrome: a meta-analysis. Int Urol Nephrol 2014; 46:1383-93. [PMID: 24715228 DOI: 10.1007/s11255-014-0676-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Accepted: 02/13/2014] [Indexed: 01/10/2023]
Abstract
While many previous studies have reported an association between the p.R229Q variant of the NPHS2 gene and focal segmental glomerulosclerosis (FSGS) or steroid-resistant nephrotic syndrome (SRNS), a conclusive relationship has not been defined. In this study, we performed a meta-analysis of the published data to investigate the impact of the p.R229Q polymorphism on FSGS and SRNS patients. Despite significant heterogeneity within some of the comparisons, the results revealed significantly higher risks of SRNS in individuals homozygous for the variant allele (OR 7.411, 95% confidence interval 1.876-29.436, p = 0.004) compared to homozygous non-variant individuals. However, the carrier rate of the p.R229Q variant was not significantly different between SRNS patients and steroid-sensitive nephrotic syndrome patients. No statistically significant differences in the p.R229Q carrier rate were observed between FSGS patients and controls or FSGS patients and patients with different pathology classifications. No notable differences in the p.R229Q carrier rate were found between patients and controls in any group with early-onset disease (onset age < 18). In conclusion, our meta-analysis suggests that for adult-onset disease (onset age > 18), the homozygous variant could be a potential predictor of hereditary nephrotic syndrome and that the p.R229Q allele cannot currently be considered a risk factor for predicting FSGS.
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Affiliation(s)
- Lu Lu
- Department of Traditional Chinese Medicine, ZhuJiang Hospital, Southern Medical University, Guangzhou, 510280, China
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Jain V, Feehally J, Jones G, Robertson L, Nair D, Vasudevan P. Steroid-resistant nephrotic syndrome with mutations in NPHS2 (podocin): report from a three-generation family. Clin Kidney J 2014; 7:303-5. [PMID: 25852895 PMCID: PMC4377750 DOI: 10.1093/ckj/sfu028] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2013] [Revised: 02/28/2014] [Accepted: 02/28/2014] [Indexed: 11/26/2022] Open
Abstract
Genetic causes of steroid-resistant nephrotic syndrome are being increasingly recognized. Mutations in NPHS2, which encodes the glomerular protein podocin, account for up to 17% of sporadic and 40% of familial cases, where they display an autosomal-recessive pattern of inheritance. This report describes a non-consanguineous family with three generations of individuals who are either compound heterozygotes for mutations in NPHS2 or who have inherited a mutation and a non-neutral polymorphism (R229Q). As well as providing an aetiological explanation, identifying pathogenic mutations and considering genotype-phenotype correlations can provide prognostic information and lead to changes in genetic counselling and management.
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Affiliation(s)
- Vani Jain
- Department of Clinical Genetics , Leicester Royal Infirmary, University Hospitals of Leicester , Leicester , UK
| | - John Feehally
- Department of Nephrology , Leicester General Hospital, University Hospitals of Leicester , Leicester , UK
| | - Gabriela Jones
- Department of Clinical Genetics , Leicester Royal Infirmary, University Hospitals of Leicester , Leicester , UK
| | - Lisa Robertson
- Department of Clinical Genetics , Leicester Royal Infirmary, University Hospitals of Leicester , Leicester , UK
| | - Dheepa Nair
- Department of Clinical Genetics , Leicester Royal Infirmary, University Hospitals of Leicester , Leicester , UK
| | - Pradeep Vasudevan
- Department of Clinical Genetics , Leicester Royal Infirmary, University Hospitals of Leicester , Leicester , UK
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Brown EJ, Pollak MR, Barua M. Genetic testing for nephrotic syndrome and FSGS in the era of next-generation sequencing. Kidney Int 2014; 85:1030-8. [PMID: 24599252 PMCID: PMC4118212 DOI: 10.1038/ki.2014.48] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Revised: 01/07/2014] [Accepted: 01/09/2014] [Indexed: 12/11/2022]
Abstract
The haploid human genome is composed of three billion base pairs, about one percent of which consists of exonic regions, the coding sequence for functional proteins, also now known as the “exome”. The development of next-generation sequencing makes it possible from a technical and economic standpoint to sequence an individual’s exome but at the cost of generating long lists of gene variants that are not straightforward to interpret. Various public consortiums such as the 1000 Genomes Project and the NHLBI Exome Sequencing Project have sequenced the exomes and a subset of entire genomes of over 2500 control individuals with ongoing efforts to further catalogue genetic variation in humans.1 The use of these public databases facilitates the interpretation of these variant lists produced by exome sequencing and, as a result, novel genetic variants linked to disease are being discovered and reported at a record rate. However, the interpretation of these results and their bearing on diagnosis, prognosis, and treatment is becoming ever more complicated. Here, we discuss the application of genetic testing to individuals with focal and segmental glomerulosclerosis (FSGS), taking a historical perspective on gene identification and its clinical implications along with the growing potential of next-generation sequencing.
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Affiliation(s)
- Elizabeth J Brown
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Martin R Pollak
- Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA
| | - Moumita Barua
- 1] Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA [2] Department of Medicine, Toronto General Hospital, Toronto, Ontario, Canada
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Mutation-dependent recessive inheritance of NPHS2-associated steroid-resistant nephrotic syndrome. Nat Genet 2014; 46:299-304. [PMID: 24509478 DOI: 10.1038/ng.2898] [Citation(s) in RCA: 111] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2013] [Accepted: 01/17/2014] [Indexed: 02/07/2023]
Abstract
Monogenic disorders result from defects in a single gene. According to Mendel's laws, these disorders are inherited in either a recessive or dominant fashion. Autosomal-recessive disorders require a disease-causing variant on both alleles, and according to our current understanding, their pathogenicities are not influenced by each other. Here we present an autosomal-recessive disorder, nephrotic syndrome type 2 (MIM 600995), in which the pathogenicity of an NPHS2 allele encoding p.Arg229Gln depends on the trans-associated mutation. We show that, contrary to expectations, this allele leads to a disease phenotype only when it is associated specifically with certain 3' NPHS2 mutations because of an altered heterodimerization and mislocalization of the encoded p.Arg229Gln podocin. The disease-associated 3' mutations exert a dominant-negative effect on p.Arg229Gln podocin but behave as recessive alleles when associated with wild-type podocin. Therefore, the transmission rates for couples carrying the disease-associated mutations and p.Arg229Gln may be substantially different from those expected in autosomal-recessive disorders.
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Laurin LP, Lu M, Mottl AK, Blyth ER, Poulton CJ, Weck KE. Podocyte-associated gene mutation screening in a heterogeneous cohort of patients with sporadic focal segmental glomerulosclerosis. Nephrol Dial Transplant 2014; 29:2062-9. [DOI: 10.1093/ndt/gft532] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
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Bouchireb K, Boyer O, Gribouval O, Nevo F, Huynh-Cong E, Morinière V, Campait R, Ars E, Brackman D, Dantal J, Eckart P, Gigante M, Lipska BS, Liutkus A, Megarbane A, Mohsin N, Ozaltin F, Saleem MA, Schaefer F, Soulami K, Torra R, Garcelon N, Mollet G, Dahan K, Antignac C. NPHS2Mutations in Steroid-Resistant Nephrotic Syndrome: A Mutation Update and the Associated Phenotypic Spectrum. Hum Mutat 2013; 35:178-86. [DOI: 10.1002/humu.22485] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Accepted: 11/05/2013] [Indexed: 01/10/2023]
Affiliation(s)
- Karim Bouchireb
- Assistance Publique-Hôpitaux de Paris, Service de Néphrologie Pédiatrique; Centre de Référence des Maladies Rénales Héréditaires (MARHEA), Hôpital Necker-Enfants Malades; Paris France
- Inserm U983; Institut Imagine, Hôpital Necker-Enfants Malades; Paris France
- Université Paris Descartes-Sorbonne Paris Cité; Paris France
| | - Olivia Boyer
- Assistance Publique-Hôpitaux de Paris, Service de Néphrologie Pédiatrique; Centre de Référence des Maladies Rénales Héréditaires (MARHEA), Hôpital Necker-Enfants Malades; Paris France
- Inserm U983; Institut Imagine, Hôpital Necker-Enfants Malades; Paris France
- Université Paris Descartes-Sorbonne Paris Cité; Paris France
| | - Olivier Gribouval
- Inserm U983; Institut Imagine, Hôpital Necker-Enfants Malades; Paris France
- Université Paris Descartes-Sorbonne Paris Cité; Paris France
| | - Fabien Nevo
- Inserm U983; Institut Imagine, Hôpital Necker-Enfants Malades; Paris France
- Université Paris Descartes-Sorbonne Paris Cité; Paris France
| | - Evelyne Huynh-Cong
- Inserm U983; Institut Imagine, Hôpital Necker-Enfants Malades; Paris France
- Université Paris Descartes-Sorbonne Paris Cité; Paris France
| | - Vincent Morinière
- Assistance Publique-Hôpitaux de Paris; Département de Génétique, Hôpital Necker-Enfants Malades; Paris France
| | - Raphaëlle Campait
- Assistance Publique-Hôpitaux de Paris; Département de Génétique, Hôpital Necker-Enfants Malades; Paris France
| | - Elisabet Ars
- Molecular Biology Laboratory; Fundació Puigvert, Instituto de Investigaciones Biomédicas Sant Pau (IIB-Sant Pau), Universitat Autònoma de Barcelona, REDinREN, Instituto de Investigación Carlos III; Barcelona Spain
| | - Damien Brackman
- Department of Pediatrics; Haukeland University Hospital; Bergen Norway
| | - Jacques Dantal
- Service de Néphrologie et Immunologie Clinique; ITERT, CHU Hôtel Dieu; Nantes France
| | | | - Maddalena Gigante
- Department of Medical and Surgical Sciences; University of Foggia; Foggia Italy
| | - Beata S. Lipska
- Department of Biology and Genetics; Medical University of Gdansk; Gdansk 80-211 Poland
| | - Aurélia Liutkus
- Service de Néphrologie et Rhumatologie Pédiatriques; Centre de référence des Maladies Rénales Rares, Hôpital Femme Mère Enfant; Bron France
| | - André Megarbane
- Unité de Génétique Médicale, Faculté de Médecine; Université Saint Joseph; Beirut Lebanon
| | - Nabil Mohsin
- Department of Nephrology; Royal Hospital; Muscat Oman
| | - Fatih Ozaltin
- Nephrogenetics Laboratory, Department of Pediatric Nephrology; Hacettepe University Faculty of Medicine; Ankara Turkey
| | - Moin A. Saleem
- Department of Paediatric Nephrology; Bristol Royal Hospital for Children, Academic Renal Unit, School of Clinical Sciences, University of Bristol; Bristol UK
| | - Franz Schaefer
- PodoNet Consortium; Division of Pediatric Nephrology, Heidelberg University Center for Pediatrics and Adolescent Medicine; Heidelberg Germany
| | - Kenza Soulami
- CHU Ibn Rochd; Service de Néphrologie Dialyse Transplantation; Casablanca Morocco
| | - Roser Torra
- Nephrology Department; Fundació Puigvert, Instituto de Investigaciones Biomédicas Sant Pau (IIB-Sant Pau), Universitat Autònoma de Barcelona, REDinREN, Instituto de Investigación Carlos III; Barcelona Spain
| | - Nicolas Garcelon
- Assistance Publique-Hôpitaux de Paris; Département de Génétique, Hôpital Necker-Enfants Malades; Paris France
- Inserm U872; Institut Imagine, Hôpital Necker-Enfants Malades; Paris France
| | - Géraldine Mollet
- Inserm U983; Institut Imagine, Hôpital Necker-Enfants Malades; Paris France
- Université Paris Descartes-Sorbonne Paris Cité; Paris France
| | - Karin Dahan
- Centre de Génétique Humaine; Université Catholique de Louvain; Bruxelles Belgique
| | - Corinne Antignac
- Assistance Publique-Hôpitaux de Paris; Département de Génétique, Hôpital Necker-Enfants Malades; Paris France
- Inserm U983; Institut Imagine, Hôpital Necker-Enfants Malades; Paris France
- Université Paris Descartes-Sorbonne Paris Cité; Paris France
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Kari JA, El-Desoky SM, Gari M, Malik K, Vega-Warner V, Lovric S, Bockenhauer D. Steroid-resistant nephrotic syndrome: impact of genetic testing. Ann Saudi Med 2013; 33:533-8. [PMID: 24413855 PMCID: PMC6074900 DOI: 10.5144/0256-4947.2013.533] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND AND OBJECTIVES Mutations in several genes are known to cause steroid-resistant nephrotic syndome (SRNS), most commonly in NPHS1, NPHS2, and WT1. Our aims were to determine the frequency of mutations in these genes in children with SRNS, the response of patients with SRNS to various immunosuppressants, and the disease outcome, and to review the predictive value of genetic testing and renal biopsy result. DESIGN AND SETTINGS A retrospective review was performed of the medical records for all children with SRNS who were treated and followed-up in the Pediatric Nephrology Unit of King Abdulaziz University Hospital (KAUH), Jeddah, Saudi Arabia from 2002-2012. PATIENTS AND METHODS We retrospectively reviewed the medical records of children above 1 year of age, who presented with SRNS to KAUH, Jeddah, Saudi Arabia, in the 10-year interval from 2002-2012 and for whom the results of genetic testing for NPHS1, NPHS2, and WT1 were available. We compared the clinical phenotype, including response to treatment and renal outcome to genotype data. RESULTS We identified 44 children with a clinical diagnosis of SRNS in whom results of genetic testing were available. Presumably disease-causing mutations were detected in 5 children (11.4%) of which 3 (6.8%) had NPHS2 mutation and 2 (4.5%) had NPHS1 mutation. Renal biopsy revealed minimal change disease (MCD) or variants in 17 children, focal segmental glomerulosclerosis (FSGS) in 23 children, membranoproliferative changes (MPGN) in 2 children, and IgA nephropathy in another 2 children. Children with MCD on biopsy were more likely to respond to treatment than those with FSGS. None of those with an identified genetic cause showed any response to treatment. CONCLUSION The frequency of identified disease-causing mutations in children older than 1 year with SRNS presented to KAUH was 11.4%, and these patients showed no response to treatment. Initial testing for gene mutation in children with SRNS may obviate the need for biopsy, and the use of immunosuppressive treatment in children with disease due to NPHS1 or NPHS2 mutations. Renal biopsy was useful in predicting response in those without genetic mutations.
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Affiliation(s)
- Jameela A Kari
- Jameela Abdulaziz Kari, Pediatrics, King Abdulaziz University,, PO Box 13042 Jeddah 21943, Saudi Arabia, T: 966-505-677904, F: 966-22-408-8353,
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Joshi S, Andersen R, Jespersen B, Rittig S. Genetics of steroid-resistant nephrotic syndrome: a review of mutation spectrum and suggested approach for genetic testing. Acta Paediatr 2013; 102:844-56. [PMID: 23772861 DOI: 10.1111/apa.12317] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Revised: 05/21/2013] [Accepted: 06/10/2013] [Indexed: 01/03/2023]
Abstract
UNLABELLED Identification of genes, associated mutations and genotype-phenotype correlations in steroid-resistant nephrotic syndrome (SRNS) is being translated to clinical practice through genetic testing. This review provides an update on the genes and mutations associated with SRNS along with a suggested approach for genetic testing in patients with SRNS. CONCLUSION The number of indentified genes associated with SRNS is increasing along with our understanding of their impact on treatment response and risk of recurrence. A systematic approach to genetic testing in patients with SRNS might aid the physician in selecting appropriate treatment.
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Affiliation(s)
- S Joshi
- Department of Clinical Medicine - The Department of Pediatrics; Research Laboratory-A; Aarhus University Hospital; Aarhus N Denmark
| | - R Andersen
- Department of Clinical Medicine - The Department of Pediatrics; Research Laboratory-A; Aarhus University Hospital; Aarhus N Denmark
| | - B Jespersen
- Department of Clinical Medicine - The Department of Medicine and Nephrology C; Aarhus University Hospital; Aarhus N Denmark
| | - S Rittig
- Department of Clinical Medicine - The Department of Pediatrics; Research Laboratory-A; Aarhus University Hospital; Aarhus N Denmark
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Beck L, Bomback AS, Choi MJ, Holzman LB, Langford C, Mariani LH, Somers MJ, Trachtman H, Waldman M. KDOQI US commentary on the 2012 KDIGO clinical practice guideline for glomerulonephritis. Am J Kidney Dis 2013; 62:403-41. [PMID: 23871408 DOI: 10.1053/j.ajkd.2013.06.002] [Citation(s) in RCA: 158] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Accepted: 06/04/2013] [Indexed: 01/28/2023]
Abstract
Glomerulonephritis (GN) is an important cause of morbidity and mortality in patients of all ages throughout the world. Because these disorders are relatively rare, it is difficult to perform randomized clinical trials to define optimal treatment for many of the specific glomerulopathies. In the absence of high-grade evidence to guide the care of glomerular diseases, in June 2012, KDIGO (Kidney Disease: Improving Global Outcomes) published an international clinical guideline for GN. The Work Group report represents an important review of the literature in this area and offers valid and useful guidelines for the most common situations that arise in the management of patients with glomerular disease. This commentary, developed by a panel of clinical experts convened by the National Kidney Foundation, attempts to put the GN guideline into the context of the US health care system. Overall, we support the vast majority of the recommendations and highlight select areas in which epidemiological factors and medical practice patterns in this country justify modifications and adjustments in order to achieve favorable outcomes. There remain large gaps in our knowledge of the best approaches to treat glomerular disease and we strongly endorse an expanded clinical research effort to improve the health and long-term outcomes of children and adults with GN.
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Affiliation(s)
- Laurence Beck
- Boston University School of Medicine, Boston, MA, USA
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Lipska BS, Iatropoulos P, Maranta R, Caridi G, Ozaltin F, Anarat A, Balat A, Gellermann J, Trautmann A, Erdogan O, Saeed B, Emre S, Bogdanovic R, Azocar M, Balasz-Chmielewska I, Benetti E, Caliskan S, Mir S, Melk A, Ertan P, Baskin E, Jardim H, Davitaia T, Wasilewska A, Drozdz D, Szczepanska M, Jankauskiene A, Higuita LMS, Ardissino G, Ozkaya O, Kuzma-Mroczkowska E, Soylemezoglu O, Ranchin B, Medynska A, Tkaczyk M, Peco-Antic A, Akil I, Jarmolinski T, Firszt-Adamczyk A, Dusek J, Simonetti GD, Gok F, Gheissari A, Emma F, Krmar RT, Fischbach M, Printza N, Simkova E, Mele C, Ghiggeri GM, Schaefer F. Genetic screening in adolescents with steroid-resistant nephrotic syndrome. Kidney Int 2013; 84:206-13. [PMID: 23515051 DOI: 10.1038/ki.2013.93] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Revised: 12/31/2012] [Accepted: 01/10/2013] [Indexed: 02/08/2023]
Abstract
Genetic screening paradigms for congenital and infantile nephrotic syndrome are well established; however, screening in adolescents has received only minor attention. To help rectify this, we analyzed an unselected adolescent cohort of the international PodoNet registry to develop a rational screening approach based on 227 patients with nonsyndromic steroid-resistant nephrotic syndrome aged 10-20 years. Of these, 21% had a positive family history. Autosomal dominant cases were screened for WT1, TRPC6, ACTN4, and INF2 mutations. All other patients had the NPHS2 gene screened, and WT1 was tested in sporadic cases. In addition, 40 sporadic cases had the entire coding region of INF2 tested. Of the autosomal recessive and the sporadic cases, 13 and 6%, respectively, were found to have podocin-associated nephrotic syndrome, and 56% of them were compound heterozygous for the nonneutral p.R229Q polymorphism. Four percent of the sporadic and 10% of the autosomal dominant cases had a mutation in WT1. Pathogenic INF2 mutations were found in 20% of the dominant but none of the sporadic cases. In a large cohort of adolescents including both familial and sporadic disease, NPHS2 mutations explained about 7% and WT1 4% of cases, whereas INF2 proved relevant only in autosomal dominant familial disease. Thus, screening of the entire coding sequence of NPHS2 and exons 8-9 of WT1 appears to be the most rational and cost-effective screening approach in sporadic juvenile steroid-resistant nephrotic syndrome.
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Affiliation(s)
- Beata S Lipska
- Division of Pediatric Nephrology, Center for Pediatric and Adolescent Medicine, University of Heidelberg, Heidelberg, Germany.
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Lipska BS, Balasz-Chmielewska I, Morzuch L, Wasielewski K, Vetter D, Borzecka H, Drozdz D, Firszt-Adamczyk A, Gacka E, Jarmolinski T, Ksiazek J, Kuzma-Mroczkowska E, Litwin M, Medynska A, Silska M, Szczepanska M, Tkaczyk M, Wasilewska A, Schaefer F, Zurowska A, Limon J. Mutational analysis in podocin-associated hereditary nephrotic syndrome in Polish patients: founder effect in the Kashubian population. J Appl Genet 2013; 54:327-33. [PMID: 23645318 PMCID: PMC3721000 DOI: 10.1007/s13353-013-0147-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 03/22/2013] [Accepted: 03/27/2013] [Indexed: 01/18/2023]
Abstract
Hereditary nephrotic syndrome is caused by mutations in a number of different genes, the most common being NPHS2. The aim of the study was to identify the spectrum of NPHS2 mutations in Polish patients with the disease. A total of 141 children with steroid-resistant nephrotic syndrome (SRNS) were enrolled in the study. Mutational analysis included the entire coding sequence and intron boundaries of the NPHS2 gene. Restriction fragment length polymorphism (RFLP) and TaqMan genotyping assay were applied to detect selected NPHS2 sequence variants in 575 population-matched controls. Twenty patients (14 %) had homozygous or compound heterozygous NPHS2 mutations, the most frequent being c.1032delT found in 11 children and p.R138Q found in four patients. Carriers of the c.1032delT allele were exclusively found in the Pomeranian (Kashubian) region, suggesting a founder effect origin. The 14 % NPHS2 gene mutation detection rate is similar to that observed in other populations. The heterogeneity of mutations detected in the studied group confirms the requirement of genetic testing the entire NPHS2 coding sequence in Polish patients, with the exception of Kashubs, who should be initially screened for the c.1032delT deletion.
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Affiliation(s)
- Beata S Lipska
- Department of Biology and Genetics, Medical University of Gdansk, Debinki str. 1, 80211, Gdansk, Poland.
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A molecular genetic analysis of childhood nephrotic syndrome in a cohort of Saudi Arabian families. J Hum Genet 2013; 58:480-9. [PMID: 23595123 DOI: 10.1038/jhg.2013.27] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2012] [Revised: 03/02/2013] [Accepted: 03/21/2013] [Indexed: 02/08/2023]
Abstract
Nephrotic syndrome (NS) is a renal disease characterized by heavy proteinuria, hypoalbuminemia, edema and hyperlipidemia. Its presentation within the first 3 months of life or in multiple family members suggests an underlying inherited cause. To determine the frequency of inherited NS, 62 cases (representing 49 families with NS) from Saudi Arabia were screened for mutations in NPHS1, NPHS2, LAMB2, PLCE1, CD2AP, MYO1E, WT1, PTPRO and Nei endonuclease VIII-like 1 (NEIL1). We detected likely causative mutations in 25 out of 49 families studied (51%). We found that the most common genetic cause of NS in our cohort was a homozygous mutation in the NPHS2 gene, found in 11 of the 49 families (22%). Mutations in the NPHS1 and PLCE1 genes allowed a molecular genetic diagnosis in 12% and 8% of families, respectively. We detected novel MYO1E mutations in three families (6%). No mutations were found in WT1, PTPRO or NEIL1. The pathogenicity of novel variants was analyzed by in silico tests and by genetic screening of ethnically matched control populations. This is the first report describing the molecular genetics of NS in the Arabian Peninsula.
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Maas RJH, Deegens JKJ, van den Brand JAJG, Cornelissen EAM, Wetzels JFM. A retrospective study of focal segmental glomerulosclerosis: clinical criteria can identify patients at high risk for recurrent disease after first renal transplantation. BMC Nephrol 2013; 14:47. [PMID: 23433074 PMCID: PMC3585752 DOI: 10.1186/1471-2369-14-47] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Accepted: 02/14/2013] [Indexed: 03/13/2023] Open
Abstract
Background Focal segmental glomerulosclerosis (FSGS) is a frequent cause of end-stage renal disease. Renal transplantation in patients with FSGS is often complicated by disease recurrence, which is associated with poor outcome. There are no tests that reliably predict recurrence of FSGS after transplantation. The aim of this study was to evaluate if clinical criteria can identify patients at high risk for recurrent disease. Methods We retrospectively studied 94 patients who received a first renal transplant at a median age of 37 years (range 5–69 years). Patients were assigned to one of three groups: familial or genetic FSGS (group I; n=18), secondary FSGS (group II; n=10) and idiopathic FSGS (group III; n=66). Pretransplant clinical characteristics were analyzed to determine predictors of a recurrence after transplantation. Results FSGS only recurred in patients with idiopathic FSGS (group III; 42%). Patients with a recurrence had a significantly lower serum albumin, higher 24-hour proteinuria and higher estimated glomerular filtration rate at diagnosis. Serum albumin at diagnosis was the only independent predictor of a recurrence in patients with idiopathic FSGS. Patients with recurrent FSGS had more acute rejection episodes (54% vs. 27%, P =0.02) and lower five year graft survival compared to patients without a recurrence (50 vs. 82%, P <0.01). Conclusions Clinical criteria allow identification of patients at high risk of recurrent FSGS after renal transplantation. This information can be used in the counseling and management of patients with FSGS.
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Affiliation(s)
- Rutger J H Maas
- Department of Nephrology 464, Radboud University Nijmegen Medical Center, PO Box 9101, Nijmegen, HB 6500, The Netherlands.
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Che R, Zhang A. Mechanisms of Glucocorticoid Resistance in Idiopathic Nephrotic Syndrome. ACTA ACUST UNITED AC 2013; 37:360-78. [DOI: 10.1159/000350163] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/19/2013] [Indexed: 11/19/2022]
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A spectrum of novel NPHS1 and NPHS2 gene mutations in pediatric nephrotic syndrome patients from Pakistan. Gene 2012; 502:133-7. [PMID: 22565185 DOI: 10.1016/j.gene.2012.04.063] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Accepted: 04/22/2012] [Indexed: 01/10/2023]
Abstract
BACKGROUND Mutations in the NPHS1 and NPHS2 genes are among the main causes of early-onset and familial steroid resistant nephrotic syndrome respectively. This study was carried out to assess the frequencies of mutations in these two genes in a cohort of Pakistani pediatric NS patients. METHODS Mutation analysis was carried out by direct sequencing of the NPHS1 and NPHS2 genes in 145 nephrotic syndrome (NS) patients. This cohort included 36 samples of congenital or infantile onset NS cases and 39 samples of familial cases obtained from 30 families. RESULTS A total of 7 homozygous (6 novel) mutations were found in the NPHS1 gene and 4 homozygous mutations in the NPHS2 gene. All mutations in the NPHS1 gene were found in the early onset cases. Of these, one patient has a family history of NS. Homozygous p.R229Q mutation in the NPHS2 gene was found in two children with childhood-onset NS. CONCLUSIONS Our results show a low prevalence of disease causing mutations in the NPHS1 (22% early onset, 5.5% overall) and NPHS2 (3.3% early onset and 3.4% overall) genes in the Pakistani NS children as compared to the European populations. In contrast to the high frequency of the NPHS2 gene mutations reported for familial SRNS in Europe, no mutation was found in the familial Pakistani cases. To our knowledge, this is the first comprehensive screening of the NPHS1 and NPHS2 gene mutations in sporadic and familial NS cases from South Asia.
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Voskarides K, Arsali M, Athanasiou Y, Elia A, Pierides A, Deltas C. Evidence that NPHS2-R229Q predisposes to proteinuria and renal failure in familial hematuria. Pediatr Nephrol 2012; 27:675-9. [PMID: 22228437 DOI: 10.1007/s00467-011-2084-6] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Revised: 11/23/2011] [Accepted: 11/23/2011] [Indexed: 10/14/2022]
Abstract
BACKGROUND Familial hematuria (FH) is associated with at least two pathological entities: thin basement membrane nephropathy (TBMN), caused by heterozygous COL4A3/COL4A4 mutations, and C3 nephropathy caused by CFHR5 mutations. It is now known that TBMN patients develop proteinuria and changes of focal segmental glomerulosclerosis when biopsied. End-stage kidney disease (ESKD) is observed in 20% of carriers, at ages 50-70. A similar progression is observed in CFHR5 nephropathy. Recent evidence suggests that NPHS2-R229Q, a podocin polymorphism, may contribute to proteinuria in TBMN and to micro-albuminuria in the general population. CASE-DIAGNOSIS/TREATMENT NPHS2-R229Q was screened in a Cypriot FH cohort. 102 TBMN patients with three known COL4 mutations and 45 CFHR5 male patients with a single mutation were categorized as "Mild" or "Severe", based on the presence of microhematuria only, or proteinuria and chronic kidney disease. Nine R229Q carriers were found in the "Severe" category and none in the "Mild" (p=0.010 for genotypic association; p=0.043 for allelic association, adjusted for patients' relatedness), thus supporting the possible contribution of 229Q allele in disease progress. CONCLUSIONS Our results offer more evidence that in patients with FH, NPHS2-R229Q predisposes to proteinuria and ESKD. R229Q may be a good prognostic marker for young hematuric patients.
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Affiliation(s)
- Konstantinos Voskarides
- Department of Biological Sciences, Molecular Medicine Research Center and Laboratory of Molecular and Medical Genetics, University of Cyprus, Kallipoleos 75, 1678 Nicosia, Cyprus
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