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Yadav M, Jadon T, Singh G, Devi KG, Chandan M, Khandelwal P, Meena J, Geetha TS, Faruq M, Hari P, Sinha A, Bagga A. Spectrum of Alport syndrome in an Indian cohort. Pediatr Nephrol 2024:10.1007/s00467-024-06507-1. [PMID: 39278986 DOI: 10.1007/s00467-024-06507-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2024] [Revised: 08/06/2024] [Accepted: 08/13/2024] [Indexed: 09/18/2024]
Abstract
BACKGROUND Next-generation sequencing has enabled non-invasive diagnosis of type IV collagen disease in clinical settings other than the typical presentation of Alport syndrome (AS). METHODS We reviewed the clinical and histological records of children diagnosed with Alport syndrome based on next-generation sequencing. Variants on clinical exome sequencing were categorized using ACMG 2015 criteria. RESULTS During 2015-2023, we found 43 patients (34 boys) with 39 variants in COL4A5 (n = 27), COL4A4 (n = 7), and COL4A3 (n = 5). Thirty, 8, and 5 patients had X-linked, autosomal recessive, and autosomal dominant disease, respectively. The median (IQR) age and eGFR at diagnosis were 10 (7-13) years and 100.1 (59-140) ml/min/1.73 m2, respectively. Fifteen patients were initially diagnosed with steroid-resistant nephrotic syndrome. Alport syndrome was suspected in these patients due to persistent microscopic hematuria, eGFR < 90 ml/min/1.73 m2, characteristic histology, and/or non-response to immunosuppression. Of 26 patients who underwent kidney biopsy, light microscopy revealed focal segmental glomerulosclerosis, minimal change disease, and mesangial proliferative glomerulonephritis in 9, 9, and 8 patients, respectively. Electron microscopy (n = 18) showed characteristic glomerular basement membrane changes and/or foot process effacement in 12 and 16 cases, respectively. Twenty-one patients (48.8%) had high-frequency sensorineural hearing loss, while two had lenticonus. Twelve patients progressed to chronic kidney disease stages 4-5. Median survival (IQR) with eGFR > 30 ml/min/1.73 m2 was 15.6 (13-18) years. CONCLUSIONS The phenotype of Alport syndrome varies from asymptomatic urinary abnormalities to hematuria, proteinuria and/or low eGFR, and steroid-resistant nephrotic syndrome. Adverse outcomes are common, especially in boys with X-linked disease.
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Affiliation(s)
- Menka Yadav
- Division of Nephrology, ICMR Center for Advanced Research in Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India
| | - Trishla Jadon
- Department of Pathology, All India Institute of Medical Sciences, New Delhi, India
| | - Geetika Singh
- Department of Pathology, All India Institute of Medical Sciences, New Delhi, India
| | - Kshetrimayum Ghanapriya Devi
- Division of Nephrology, ICMR Center for Advanced Research in Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India
| | - Monica Chandan
- Division of Nephrology, ICMR Center for Advanced Research in Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India
| | - Priyanka Khandelwal
- Division of Nephrology, ICMR Center for Advanced Research in Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India
| | - Jitendra Meena
- Division of Nephrology, ICMR Center for Advanced Research in Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India
| | | | - Mohammed Faruq
- Council of Scientific and Industrial Research-Institute of Genomics and Integrative Biology, Delhi, India
| | - Pankaj Hari
- Division of Nephrology, ICMR Center for Advanced Research in Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India
| | - Aditi Sinha
- Division of Nephrology, ICMR Center for Advanced Research in Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India.
| | - Arvind Bagga
- Division of Nephrology, ICMR Center for Advanced Research in Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India
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Younsi ME, Achour A, Kraoua L, Nesrine M, Sayari T, Abderrahim E, Laabidi J, Zouaghi MK, Kharrat M, Gargah T, Trabelsi M, M'rad R. Genetic study of Alport syndrome in Tunisia. Pediatr Nephrol 2024:10.1007/s00467-024-06474-7. [PMID: 39138691 DOI: 10.1007/s00467-024-06474-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2024] [Revised: 06/13/2024] [Accepted: 07/11/2024] [Indexed: 08/15/2024]
Abstract
BACKGROUND Alport syndrome is a genetic disorder affecting the kidneys, ears, and eyes, causing chronic kidney disease, sensorineural hearing loss, and ocular abnormalities. It results from pathogenic variants in the COL4A3, COL4A4, or COL4A5 genes, with different inheritance patterns: X-linked from COL4A5 variants, autosomal recessive from homozygous variants in COL4A3 or COL4A4, digenic from variants in both COL4A3 and COL4A4, and autosomal dominant from heterozygous variants in COL4A3 or COL4A4. METHODS We analyzed 45 patients with Alport syndrome from 11 Tunisian families to determine their clinical and genetic characteristics. Clinical data were collected retrospectively, and whole-exome sequencing was conducted on one patient from each family. Sanger sequencing validated pathogenic variants, and cascade screening extended the analysis to 53 individuals. RESULTS We identified nine likely pathogenic variants among 11 index cases: six novel and three known variations. Of these, five were in COL4A3, and four were in COL4A5, with variants including frameshift, nonsense, missense, and alternative splicing. Most variations affected the Gly-XY codon. Among the 45 clinically identified siblings, 30 tested positive for Alport syndrome. The cascade screening identified 3 additional affected individuals, 10 unaffected siblings, and 10 unaffected parents. The mode of inheritance was autosomal recessive in six families and X-linked in four families. CONCLUSIONS This study is the first to screen the mutational spectrum of Alport syndrome in Tunisia. It reveals novel pathogenic variants and suggests that autosomal recessive inheritance may be more common in the Tunisian population than X-linked inheritance, contrary to existing literature.
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Affiliation(s)
- Mariem El Younsi
- Laboratoire de Génétique Humaine, Faculté de Médecine de Tunis, Université de Tunis El Manar, LR99ES101007, Tunis, Tunisia
| | - Ahlem Achour
- Laboratoire de Génétique Humaine, Faculté de Médecine de Tunis, Université de Tunis El Manar, LR99ES101007, Tunis, Tunisia
- Service des Maladies Congénitales Et Héréditaires, Hôpital Charles Nicolle, 1006, Tunis, Tunisia
| | - Lilia Kraoua
- Laboratoire de Génétique Humaine, Faculté de Médecine de Tunis, Université de Tunis El Manar, LR99ES101007, Tunis, Tunisia
- Service des Maladies Congénitales Et Héréditaires, Hôpital Charles Nicolle, 1006, Tunis, Tunisia
| | - Mezzi Nesrine
- Laboratory of Biomedical Genomics and Oncogenetics, Pasteur Institute of Tunis, 1002, Tunis, Tunisia
| | - Taha Sayari
- Service de Néphrologie Pédiatrique, Hôpital Charles Nicolle, 1006, Tunis, Tunisia
| | - Ezzeddine Abderrahim
- Service de Médecine Interne Et de Néphrologie Adulte, Hôpital Charles Nicolle, 1006, Tunis, Tunisia
| | - Janet Laabidi
- Service Néphrologie, L'Hôpital Militaire Principal d'Instruction de Tunis, MontFleury, 1008, Tunis, Tunisia
| | - Mohamed Karim Zouaghi
- Service de Néphrologie, Dialyse Et Transplantation Rénale, Hôpital La Rabta 1007, Tunis, Tunisia
| | - Maher Kharrat
- Laboratoire de Génétique Humaine, Faculté de Médecine de Tunis, Université de Tunis El Manar, LR99ES101007, Tunis, Tunisia
| | - Tahar Gargah
- Service de Néphrologie Pédiatrique, Hôpital Charles Nicolle, 1006, Tunis, Tunisia
| | - Mediha Trabelsi
- Laboratoire de Génétique Humaine, Faculté de Médecine de Tunis, Université de Tunis El Manar, LR99ES101007, Tunis, Tunisia
- Service des Maladies Congénitales Et Héréditaires, Hôpital Charles Nicolle, 1006, Tunis, Tunisia
| | - Ridha M'rad
- Laboratoire de Génétique Humaine, Faculté de Médecine de Tunis, Université de Tunis El Manar, LR99ES101007, Tunis, Tunisia.
- Service des Maladies Congénitales Et Héréditaires, Hôpital Charles Nicolle, 1006, Tunis, Tunisia.
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Zhang Y, Wang X, Zhou J, Ding J, Wang F. Abnormal mRNA Splicing Effect of COL4A3 to COL4A5 Unclassified Variants. Kidney Int Rep 2023; 8:1399-1406. [PMID: 37441478 PMCID: PMC10334324 DOI: 10.1016/j.ekir.2023.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 03/30/2023] [Accepted: 04/03/2023] [Indexed: 07/15/2023] Open
Abstract
Introduction Genetic diagnosis of Alport syndrome (AS), which results from pathogenic variants in COL4A3, COL4A4, or COL4A5 genes, is hindered by large numbers of unclassified variants detected using next-generation sequencing (NGS). We examined the impact on splicing of variants of uncertain significance in COL4A3 to COL4A5. Methods Nine unrelated patients with clinical diagnosis or suspicion of AS were enrolled according to the criteria. Their clinical and genetic data were collected. Blood and urine samples were obtained from the patients and their family members. Sanger sequencing was used to confirm the 9 COL4A3 to COL4A5 unclassified variants identified by NGS. COL4A3 to COL4A5 mRNAs from urine were analyzed using targeted reverse transcription polymerase chain reaction and direct sequencing. Results Nine COL4A3 to COL4A5 unclassified variants were found to alter mRNAs splicing. Skipping of an exon or an exon fragment was induced by variants COL4A3 c.828+5G>A; COL4A4 c.3506-13_3528del; and COL4A5 c.451A>G (p. [Ile151Val]), c.2042-9 T>G, c.2689 G>C (p. [Glu897Gln]) and c.1033-10_1033-2delGGTAATAAA. Retention of an intron fragment was caused by variants COL4A3 c.3211-30G>T, and COL4A5 c.4316-20T>A and c.1033-10 G>A, respectively. The 9 families in this study obtained genetic diagnosis of AS, including 3 with autosomal recessive AS and 6 with X-linked AS. Conclusions Our findings demonstrate that urine mRNA analysis facilitates the identification of abnormal splicing of unclassified variants in Alport genes, which provides evidence of routine use of RNA analysis to improve genetic diagnosis of AS.
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Affiliation(s)
- Yanqin Zhang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Xiaoyuan Wang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Jianmei Zhou
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Jie Ding
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Fang Wang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
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Xu H, Yu X, Li Y, Huang Z, Zhang L, Min Q, Bi J, Li Z, Liu L, Liang Y, Xu Z, Sun H, Yang S, Shao M. Collagen IV and Podocyte-Related Gene Variants in Patients with Concurrent IgA Nephropathy and Thin Basement Membrane Nephropathy. Nephron Clin Pract 2022; 147:301-310. [PMID: 36349777 PMCID: PMC10906470 DOI: 10.1159/000526971] [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: 01/14/2022] [Accepted: 08/30/2022] [Indexed: 03/03/2024] Open
Abstract
INTRODUCTION IgA nephropathy is the most common primary glomerulonephritis among adults in clinic. Thin basement membrane nephropathy is often underestimated or even omitted if it coincides with IgA nephropathy. Therefore, it is necessary to study the epidemiological, clinical, and molecular characteristics of the concurrence of this entity. METHODS Eight patients with concurrent IgA nephropathy and thin basement membrane nephropathy (IgA-T) were retrospectively analyzed based on their clinicopathological characteristics. Genetic analysis was performed using whole-exome sequencing and Sanger's sequencing. Data of the patients with IgA nephropathy and normal basement membrane (IgA-N) and variants in the local in-house database were used as controls. All candidate variants were assessed in silico. RESULTS The clinical manifestations of patients with IgA-T were hematuria, proteinuria, and renal insufficiency. Histopathological analysis showed mild mesangial hyperplasia, focal segmental glomerulosclerosis, podocyte activation, and foot process fusion. Crescent was rarely seen. COL4A and/or podocyte cytoskeleton and mitochondria-related gene variants were detected in seven IgA-T patients. Three patients exhibited pathogenic variants of COL4A, including a new variant. All IgA-T and one IgA-N patient possessed ITGB4 and/or PLEC variants, but there was no corresponding genotype-phenotype relationship. Six patients possessed other podocyte cytoskeleton and mitochondria-related gene variants such as NPHS2, SRGAP1, MYO1E, MYO1C, WT1, and COQ9, which were first reported in patients with IgA-T and were not in controls. Altogether, there were no significant differences in the degrees of proteinuria, serum creatinine, and eGFR during the follow-up period of 5-10 years, but there was a significant difference in the degree of proteinuria between IgA-T patients with podocyte-related gene variants and IgA-N patients. In the IgA-T group, patients with podocyte-related gene variants seemed predisposed to progress than patients without those variants, with higher proteinuria and serum creatinine and reduced eGFR. CONCLUSION Concurrent thin basement membrane nephropathy and/or heterozygous COL4A gene pathogenic variants do not necessarily predict the short-term progress of sporadic IgA nephropathy in adults. Predisposition factors for this disease progression should be considered for detecting the variants of COL4A and podocyte cytoskeleton and mitochondria-related genes simultaneously, which also manifests the complexity and heterogeneity of IgA nephropathy with concurrent thin basement membrane nephropathy.
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Affiliation(s)
- Hua Xu
- Department of Pathology, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen Traditional Chinese Medicine Hospital, Shenzhen, China
| | - XueWen Yu
- Department of Pathology, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen Traditional Chinese Medicine Hospital, Shenzhen, China
| | - Yun Li
- Department of Nephrology, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen Traditional Chinese Medicine Hospital, Shenzhen, China
| | - ZhongHua Huang
- Department of Pathology, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen Traditional Chinese Medicine Hospital, Shenzhen, China
| | - Lu Zhang
- Department of Pathology, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen Traditional Chinese Medicine Hospital, Shenzhen, China
| | - QinQin Min
- Department of Pathology, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen Traditional Chinese Medicine Hospital, Shenzhen, China
| | - JiaXin Bi
- Department of Pathology, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen Traditional Chinese Medicine Hospital, Shenzhen, China
| | - ZhenGuo Li
- Department of Pathology, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen Traditional Chinese Medicine Hospital, Shenzhen, China
| | - LingYun Liu
- Department of Pathology, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen Traditional Chinese Medicine Hospital, Shenzhen, China
| | - YingYing Liang
- Department of Pathology, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen Traditional Chinese Medicine Hospital, Shenzhen, China
| | - ZhouWen Xu
- Department of Pathology, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen Traditional Chinese Medicine Hospital, Shenzhen, China
| | - HuiLi Sun
- Department of Nephrology, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen Traditional Chinese Medicine Hospital, Shenzhen, China
| | - ShuDong Yang
- Department of Nephrology, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen Traditional Chinese Medicine Hospital, Shenzhen, China
| | - MuMin Shao
- Department of Pathology, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen Traditional Chinese Medicine Hospital, Shenzhen, China
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Ma Y, Wang Z, Liu X, Sun W, Gong Y, Liu G, Sun G. Generation and characterization of an integration-free iPSC line SDUBMSi006-A from a patient with Alport syndrome caused by COL4A3 gene mutations. Stem Cell Res 2021; 52:102237. [PMID: 33601099 DOI: 10.1016/j.scr.2021.102237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 01/18/2021] [Accepted: 02/05/2021] [Indexed: 11/17/2022] Open
Abstract
Alport syndrome (AS) is a hereditary kidney disease caused by mutations in COL4A3, COL4A4, or COL4A5 genes. Here we report the generation of an induced pluripotent stem cell line (iPSC) from an AS patient carrying compound heterozygote mutations (c.4243G > C and c.4216G > A) in COL4A3 gene using non-integrative reprogramming technology. The established iPSC line demonstrates hESC morphology, expresses pluripotency markers, has normal karyotype, and is capable of differentiating into all three germ layers in vitro.
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Affiliation(s)
- Yanyan Ma
- Key Laboratory of Experimental Teratology, Ministry of Education, Institute of Molecular Medicine and Genetics, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, China
| | - Zhendong Wang
- Department of Nephrology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, China
| | - Xiaolin Liu
- Key Laboratory of Experimental Teratology, Ministry of Education, Institute of Molecular Medicine and Genetics, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, China
| | - Wenjie Sun
- Key Laboratory of Experimental Teratology, Ministry of Education, Institute of Molecular Medicine and Genetics, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, China
| | - Yaoqin Gong
- Key Laboratory of Experimental Teratology, Ministry of Education, Institute of Molecular Medicine and Genetics, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, China
| | - Guangyi Liu
- Department of Nephrology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, China.
| | - Gongping Sun
- Key Laboratory of Experimental Teratology, Ministry of Education, Department of Histoembryology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, China.
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Wang D, Shan C, Jing X, Zhang Q, Chang H, Lin Y. Clinical Features and Familial Mutations in an Autosomal-Inherited Alport Syndrome Patient With the Presentation of Nephrotic Syndrome. Front Pediatr 2021; 9:678633. [PMID: 34858896 PMCID: PMC8631998 DOI: 10.3389/fped.2021.678633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 10/21/2021] [Indexed: 11/13/2022] Open
Abstract
Background: The aim of this study was to report the clinical features and mutations in a patient with autosomal-inherited Alport syndrome (AS). Methods: We examined the clinical data, mutation analysis results, and family tree of a patient with autosomal-inherited AS, who had nephrotic syndrome as her first manifestation. Results: The proband was a girl of 11 months who presented with nephritic and nephrotic syndromes including gross hematuria but had a normal renal function. Her treatment course was complicated by steroid resistance and a poor response to cyclosporine A and cyclophosphamide pulse therapy. Renal biopsy was performed 2 years after disease onset; light microscopy showed glomerular segmental mesangio-proliferative lesions, and type IV collagen staining showed the loss of the α3 chain in the glomerular and tubular basement membrane (GBM and TBM) and α5 chain loss in the GBM. Electron microscopy showed uneven GBM thickness, with the dense basement membrane (BM) layer obviously delaminated and torn, showing a typical "lace-like" change. The segmental BM was loosened and widened. Her father did not develop microscopic hematuria until 10 years later, while her grandmother had asymptomatic hematuria and proteinuria when the proband was diagnosed. We detected a new COL4A4 mutation in the proband, namely c.1715delG (p.G572Vfs * 81) in exon 24. Her father and grandmother carried the same mutation, but her mother and sister did not. Conclusions: We found a new potentially pathogenic mutation of COL4A4 in a patient with autosomal-inherited AS, which presented as nephrotic syndrome in infancy.
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Affiliation(s)
- Dahai Wang
- Department of Pediatric Cardiology, Nephrology and Rheumatology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Chunrong Shan
- Department of Neurology, Qingdao Women and Children's Hospital, Qingdao, China
| | - Xinxin Jing
- Department of Pediatric Cardiology, Nephrology and Rheumatology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Qiuye Zhang
- Department of Pediatric Cardiology, Nephrology and Rheumatology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Hong Chang
- Department of Pediatric Cardiology, Nephrology and Rheumatology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Yi Lin
- Department of Pediatric Cardiology, Nephrology and Rheumatology, The Affiliated Hospital of Qingdao University, Qingdao, China
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Genotype-phenotype correlations and nephroprotective effects of RAAS inhibition in patients with autosomal recessive Alport syndrome. Pediatr Nephrol 2021; 36:2719-2730. [PMID: 33772369 PMCID: PMC8370956 DOI: 10.1007/s00467-021-05040-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 02/20/2021] [Accepted: 03/02/2021] [Indexed: 02/06/2023]
Abstract
BACKGROUND Autosomal recessive Alport syndrome (ARAS) is caused by pathogenic variants in both alleles of either COL4A3 or COL4A4 genes. Reports on ARAS are rare due to small patient numbers and there are no reports on renin-angiotensin-aldosterone system (RAAS) inhibition therapy in ARAS. METHODS Retrospective study in 101 patients with ARAS from Chinese Registry Database of Hereditary Kidney Diseases and European Alport Registry. Genotype-phenotype correlations and nephroprotective effects of RAAS inhibition in ARAS were evaluated. RESULTS Median age was 15 years (range 1.5-46 years). Twelve patients progressed to stage 5 chronic kidney disease (CKD5) at median age 20.5 years. Patients without missense variants had both higher prevalence and earlier onset age of hearing loss, nephrotic-range proteinuria, more rapid decline of eGFR, and earlier onset age of CKD5 compared to patients with 1 or 2 missense variants. Most patients (79/101, 78%) currently are treated with RAAS inhibitors; median age at therapy initiation was 10 years and mean duration 6.5 ± 6.0 years. Median age at CKD5 for untreated patients was 24 years. RAAS inhibition therapy delayed CKD5 onset in those with impaired kidney function (T-III) to median age 35 years, but is undefined in treated patients with proteinuria (T-II) due to low number of events. No treated patients with microalbuminuria (T-I) progressed to CKD5. ARAS patients with 1 or 2 missense variants showed better response to treatment than patients with non-missense-variants. CONCLUSIONS Our study provides the first evidence for early use of RAAS inhibition therapy in patients with ARAS. Furthermore, genotype in ARAS correlates with response to therapy in favor of missense variants.
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Compound Mutations of the COL4A3 including a Novel Allele Identified in a Patient with Alport Syndrome. BIOMED RESEARCH INTERNATIONAL 2020; 2020:1626378. [PMID: 33524082 PMCID: PMC7673930 DOI: 10.1155/2020/1626378] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 10/08/2020] [Accepted: 10/19/2020] [Indexed: 11/17/2022]
Abstract
Alport syndrome (AS) is a hereditary nephropathy which is characterized by molecular abnormalities in collagen IV. Here, we report compound mutations of the COL4A3 gene including a novel allele identified in a patient with Alport syndrome. The patient was a 25-year-old Chinese woman. She has a history of proteinuria and hematuria with cleft lip and palate. The pathologic results were consistent with Alport syndrome. The patient received ACEI treatment but did not respond well to the treatment. Sequencing results revealed that the patient carried two heterozygous mutations in the COL4A3 gene, including a known mutation (c.4243G>C, p.G1415R), which was inherited from her father, and a previously undescribed allele (c.4216G>A, p.G1406R) inherited from her mother. To date, at least 294 different variants of COL4A3 have been reported according to the Human Gene Mutation Database (HGMD). Identification of c.4216G>A as a new AS-related mutation may contribute to both genetic diagnosis of AS and further functional study of COL4A3.
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Daso RE, Banerjee IA. Self-Assembled Peptide-Based Biocomposites for Near-Infrared Light Triggered Drug Release to Tumor Cells. Biotechnol J 2020; 15:e2000128. [PMID: 32845561 DOI: 10.1002/biot.202000128] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Revised: 07/21/2020] [Indexed: 11/11/2022]
Abstract
Peptide-based nanomaterials are increasingly gaining popularity due to their specificity, biocompatibility, and biodegradability. In this work, a new multi-layered peptide-based biocomposite for targeting MCF-7 breast cancer cells is developed. The amphipathic Fluorenylmethyloxycarbonyl (Fmoc)-Leu-Ser peptide is synthesized, which is conjugated to a tumor-targeting peptide sequence Gly-Cys-Gly-Asn-Ser to form Fmoc-L-S-G-C-G-N-S (FLS) assemblies. To the FLS assemblies, gold nanorods are then attached to develop drug delivery vehicles (DDVs). The DDVs are entrapped with the anti-cancer drug fulvestrant. Entrapment efficiency is found to be 50.6%. Release studies indicate that irradiating the gold nanorod bound DDVs at NIR wavelength (785 nm) increases drug release by fourfold compared to assemblies that are not irradiated. These results also show higher cytotoxicity and lower cell invasion due to photo-triggered drug release. Furthermore, distinct actin cytoskeletal changes are observed. Such novel peptide-based gold nanorod bound DDVs demonstrate potential in dual targeting of MCF-7 breast cancer cells.
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Affiliation(s)
- Rachel E Daso
- Department of Chemistry, Fordham University, 441 E. Fordham Road, Bronx, NY, 10458, USA
| | - Ipsita A Banerjee
- Department of Chemistry, Fordham University, 441 E. Fordham Road, Bronx, NY, 10458, USA
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Shang S, Peng F, Wang T, Wu X, Li P, Li Q, Chen XM. Genotype-phenotype correlation and prognostic impact in Chinese patients with Alport Syndrome. Mol Genet Genomic Med 2019; 7:e00741. [PMID: 31144478 PMCID: PMC6625365 DOI: 10.1002/mgg3.741] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2018] [Revised: 04/12/2019] [Accepted: 04/15/2019] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Alport Syndrome (AS) is a progressive hereditary glomerular disease. It is often accompanied by sensorineural hearing loss and ocular abnormalities and can sometimes develop into end stage renal disease (ESRD), which is caused by mutations in the genes encoding the collagen type IV family of proteins. METHODS This study analyzed the association between the clinical data of seven AS families and genes and the disease progression of different mutation types, including COL4A3 (OMIM 120070),COL4A4 (OMIM 120131), and COL4A5 (OMIM303630). RESULTS A total of six new pathogenic mutation sites, one complex heterozygous mutation at COL4A3, and a combined mutation of COL4A5 and INF2 (OMIM 610982) were identified in this study. It was revealed that the clinical manifestations of X-linked AS caused by mutations in the COL4A5 gene were more severe in males than in females. In addition, the difference in patient phenotype can be attributed to the location of gene mutations affecting the protein domain or functional domain. Our data suggested that the gene deletion and nonsense mutations had a high risk for progression to ESRD. CONCLUSION Our results revealed the spectrum of type IV collagen genes, which contribute to the enrichment of database resources and has important implications in the diagnosis, prognosis, and guiding treatment of AS.
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Affiliation(s)
- Shunlai Shang
- Department of Nephrology, State Key Laboratory of Kidney Diseases, National Clinical Research Center for Kidney Diseases, Chinese PLA General Hospital, Medical School of Chinese PLA, Chinese PLA Institute of Nephrology, Beijing, China
| | - Fei Peng
- Department of Nephrology, State Key Laboratory of Kidney Diseases, National Clinical Research Center for Kidney Diseases, Chinese PLA General Hospital, Medical School of Chinese PLA, Chinese PLA Institute of Nephrology, Beijing, China.,School of Medicine, Nankai University, Tianjin, China
| | - Tao Wang
- Department of Nephrology, State Key Laboratory of Kidney Diseases, National Clinical Research Center for Kidney Diseases, Chinese PLA General Hospital, Medical School of Chinese PLA, Chinese PLA Institute of Nephrology, Beijing, China
| | - Xiaoyuan Wu
- Department of Nephrology, State Key Laboratory of Kidney Diseases, National Clinical Research Center for Kidney Diseases, Chinese PLA General Hospital, Medical School of Chinese PLA, Chinese PLA Institute of Nephrology, Beijing, China
| | - Ping Li
- Department of Nephrology, State Key Laboratory of Kidney Diseases, National Clinical Research Center for Kidney Diseases, Chinese PLA General Hospital, Medical School of Chinese PLA, Chinese PLA Institute of Nephrology, Beijing, China
| | - Qinggang Li
- Department of Nephrology, State Key Laboratory of Kidney Diseases, National Clinical Research Center for Kidney Diseases, Chinese PLA General Hospital, Medical School of Chinese PLA, Chinese PLA Institute of Nephrology, Beijing, China
| | - Xiang M Chen
- Department of Nephrology, State Key Laboratory of Kidney Diseases, National Clinical Research Center for Kidney Diseases, Chinese PLA General Hospital, Medical School of Chinese PLA, Chinese PLA Institute of Nephrology, Beijing, China
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11
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Zhao X, Chen C, Wei Y, Zhao G, Liu L, Wang C, Zhang J, Kong X. Novel mutations of COL4A3, COL4A4, and COL4A5 genes in Chinese patients with Alport Syndrome using next generation sequence technique. Mol Genet Genomic Med 2019; 7:e653. [PMID: 30968591 PMCID: PMC6565573 DOI: 10.1002/mgg3.653] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 01/23/2019] [Accepted: 03/04/2019] [Indexed: 01/01/2023] Open
Abstract
Background Alport syndrome (AS) is an inherited progressive renal disease caused by mutations in COL4A3, COL4A4, and COL4A5 genes. The large sizes of these genes and the absence of mutation hot spots have complicated mutational analysis by routine PCR‐based approaches. In recent years, the development of next‐generation sequencing (NGS) has made possible the time‐ and cost‐effective and accurate analysis of the three genes in a single step. Methods Here, we analyze COL4A3, COL4A4, and COL4A5 simultaneously in 29 AS patients using NGS. Candidate mutations were validated by classic Sanger sequencing and Real‐time PCR. Results Twenty two new mutations and 10 known mutations were detected. Of those novel mutations, 18, 3, and 1 mutations were detected in COL4A5, COL4A4, and COL4A3, respectively. Twenty six patients showed X‐linked inheritance, one showed autosomal recessive inheritance and two showed digenic inheritance (DI). Conclusion A comparison of the clinical manifestations caused by different types of mutations in COL4A5 suggested that large fragment mutations are relatively more severe than the other missense mutations and AS by some mutations may show inter‐ and intra‐familial phenotypic variability. It is important to consider these transmission patterns in the clinical evaluation according to the results of genetic testing, especially for DI. Twenty two new mutations can expand the genotypic spectrum of AS.
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Affiliation(s)
- Xuechao Zhao
- Genetics and Prenatal Diagnosis Center, The First Affiliated Hospital of Zhengzhou University, Henan Engineering Research Center for Gene Editing of Human Genetic Disease, Erqi District, Zhengzhou, China
| | - Chen Chen
- Genetics and Prenatal Diagnosis Center, The First Affiliated Hospital of Zhengzhou University, Henan Engineering Research Center for Gene Editing of Human Genetic Disease, Erqi District, Zhengzhou, China
| | - Yanfu Wei
- Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, Research Institute of Nephrology, Zhengzhou University, Zhengzhou, China
| | - Ganye Zhao
- Genetics and Prenatal Diagnosis Center, The First Affiliated Hospital of Zhengzhou University, Henan Engineering Research Center for Gene Editing of Human Genetic Disease, Erqi District, Zhengzhou, China
| | - Lina Liu
- Genetics and Prenatal Diagnosis Center, The First Affiliated Hospital of Zhengzhou University, Henan Engineering Research Center for Gene Editing of Human Genetic Disease, Erqi District, Zhengzhou, China
| | - Conghui Wang
- Genetics and Prenatal Diagnosis Center, The First Affiliated Hospital of Zhengzhou University, Henan Engineering Research Center for Gene Editing of Human Genetic Disease, Erqi District, Zhengzhou, China
| | - Junjun Zhang
- Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, Research Institute of Nephrology, Zhengzhou University, Zhengzhou, China
| | - Xiangdong Kong
- Genetics and Prenatal Diagnosis Center, The First Affiliated Hospital of Zhengzhou University, Henan Engineering Research Center for Gene Editing of Human Genetic Disease, Erqi District, Zhengzhou, China
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12
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Zhang Y, Ding J, Zhang H, Yao Y, Xiao H, Wang S, Wang F. Effect of heterozygous pathogenic COL4A3 or COL4A4 variants on patients with X-linked Alport syndrome. Mol Genet Genomic Med 2019; 7:e647. [PMID: 30883042 PMCID: PMC6503168 DOI: 10.1002/mgg3.647] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 02/03/2019] [Accepted: 02/26/2019] [Indexed: 12/12/2022] Open
Abstract
Background Alport syndrome is an inherited renal disease caused by mutations in COL4A3, COL4A4, or COL4A5 genes. Coexisting mutations in either two of the three genes in Alport patients have been reported recently. However, the effect of heterozygous mutations in COL4A3 or COL4A4 genes in X‐linked Alport syndrome (XLAS) patients is unclear. Methods Using targeted next‐generation sequencing, six unrelated Chinese children were identified to have a combination of a pathogenic variant in COL4A5 and a heterozygous mutation in COL4A3 or COL4A4. They were three males and three females. Another three XLAS males each with only one pathogenic variant in COL4A5 were included. The clinical data were analyzed and compared between the males in two groups (group 1, males with a pathogenic variant in COL4A5 and a heterozygous pathogenic variant in COL4A3 or COL4A4; group 2, males with only one pathogenic variant in COL4A5). Results Patients with XLAS who also had heterozygous pathogenic COL4A3 or COL4A4 variants accounted for 1% of Alport syndrome. In this study, three children showed coexisting pathogenic variants in COL4A5 and COL4A3. Two children showed pathogenic variants in COL4A5 and COL4A4. One child had pathogenic variants in the three COL4A3‐5 genes, in which the pathogenic variant in COL4A5 was de novo and the pathogenic variants in COL4A4 and COL4A3 were inherited independently (in trans). The site and type of mutations in COL4A5 were similar between the two groups. It was revealed that males in group 1 presented more severe proteinuria than males in group 2 (p < 0.05). Conclusion The present study provides further evidence for complicated genotype in Alport syndrome. For the first time, we reported a case with three pathogenic variants in COL4A5, COL4A3, and COL4A4 genes. Moreover, we found that heterozygous pathogenic COL4A3 or COL4A4 variants are likely to make XLAS disease more serious.
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Affiliation(s)
- Yanqin Zhang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Jie Ding
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Hongwen Zhang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Yong Yao
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Huijie Xiao
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Suxia Wang
- Department of Electron Microscopy, Peking University First Hospital, Beijing, China
| | - Fang Wang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
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13
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Features of Autosomal Recessive Alport Syndrome: A Systematic Review. J Clin Med 2019; 8:jcm8020178. [PMID: 30717457 PMCID: PMC6406612 DOI: 10.3390/jcm8020178] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2018] [Revised: 01/27/2019] [Accepted: 01/31/2019] [Indexed: 01/16/2023] Open
Abstract
Alport syndrome (AS) is one of the most frequent hereditary nephritis leading to end-stage renal disease (ESRD). Although X-linked (XLAS) inheritance is the most common form, cases with autosomal recessive inheritance with mutations in COL4A3 or COL4A4 are being increasingly recognized. A systematic review was conducted on autosomal recessive Alport syndrome (ARAS). Electronic databases were searched using related terms (until Oct 10th, 2018). From 1601 articles searched, there were 26 eligible studies with 148 patients. Female and male patients were equally affected. About 62% of patients had ESRD, 64% had sensorineural hearing loss (SNHL) and 17% had ocular manifestation. The median at onset was 2.5 years for hematuria (HU), 21 years for ESRD, and 13 years for SNHL. Patients without missense mutations had more severe outcomes at earlier ages, while those who had one or two missense mutations had delayed onset and lower prevalence of extrarenal manifestations. Of 49 patients with kidney biopsy available for electron microscopy (EM) pathology, 42 (86%) had typical glomerular basement membrane (GBM) changes, while 5 (10%) patients showed GBM thinning only. SNHL developed earlier than previously reported. There was a genotype phenotype correlation according to the number of missense mutations. Patients with missense mutations had delayed onset of hematuria, ESRD, and SNHL and lower prevalence of extrarenal manifestations.
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14
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Zhang Y, Ding J. Renal, auricular, and ocular outcomes of Alport syndrome and their current management. Pediatr Nephrol 2018; 33:1309-1316. [PMID: 28864840 DOI: 10.1007/s00467-017-3784-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 08/01/2017] [Accepted: 08/10/2017] [Indexed: 01/27/2023]
Abstract
Alport syndrome is a hereditary glomerular basement membrane disease caused by mutations in the COL4A3/4/5 genes encoding the type IV collagen alpha 3-5 chains. Most cases of Alport syndrome are inherited as X-linked dominant, and some as autosomal recessive or autosomal dominant. The primary manifestations are hematuria, proteinuria, and progressive renal failure, whereas some patients present with sensorineural hearing loss and ocular abnormalities. Renin-angiotensin-aldosterone system blockade is proven to delay the onset of renal failure by reducing proteinuria. Renal transplantation is a curative treatment for patients who have progressed to end-stage renal disease. However, only supportive measures can be used to improve hearing loss and visual loss. Although both stem cell therapy and gene therapy aim to repair the basement membrane defects, technical difficulties require more research in Alport mice before clinical studies. Here, we review the renal, auricular, and ocular manifestations and outcomes of Alport syndrome and their current management.
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Affiliation(s)
- Yanqin Zhang
- Pediatric Department, Peking University First Hospital, Beijing, China
| | - Jie Ding
- Pediatric Department, Peking University First Hospital, Beijing, China.
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15
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Kamijo M, Kitamura M, Muta K, Uramatsu T, Obata Y, Nozu K, Kaito H, Iijima K, Mukae H, Nishino T. A case of mild phenotype Alport syndrome caused by COL4A3 mutations. CEN Case Rep 2017; 6:189-193. [PMID: 28856578 DOI: 10.1007/s13730-017-0273-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Accepted: 08/22/2017] [Indexed: 11/28/2022] Open
Abstract
In a case of 41-year-old man with mild nephropathy, Alport syndrome (AS) was diagnosed from the renal biopsy. However, the α5 chain of type IV collagen expressed in the glomerular basement membrane, which was the atypical staining pattern of AS. Genetic testing suggested autosomal recessive AS from heterozygous mutations at two positions in the type IV collagen α3 chain. These two gene mutations represented a new pattern of mutation and was suggested the association with an atypical α5 chain expression and mild phenotype.
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Affiliation(s)
- Masafumi Kamijo
- Department of Nephrology, Nagasaki University Hospital, 1-7-1 Sakamoto, Nagasaki, 852-8501, Japan
| | - Mineaki Kitamura
- Department of Nephrology, Nagasaki University Hospital, 1-7-1 Sakamoto, Nagasaki, 852-8501, Japan.
| | - Kumiko Muta
- Department of Nephrology, Nagasaki University Hospital, 1-7-1 Sakamoto, Nagasaki, 852-8501, Japan
| | - Tadashi Uramatsu
- Department of Nephrology, Nagasaki University Hospital, 1-7-1 Sakamoto, Nagasaki, 852-8501, Japan
| | - Yoko Obata
- Department of Nephrology, Nagasaki University Hospital, 1-7-1 Sakamoto, Nagasaki, 852-8501, Japan
| | - Kandai Nozu
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Hiroshi Kaito
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Kazumoto Iijima
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Hiroshi Mukae
- Department of Respiratory Medicine, Nagasaki University Hospital, Nagasaki, Japan
| | - Tomoya Nishino
- Department of Nephrology, Nagasaki University Hospital, 1-7-1 Sakamoto, Nagasaki, 852-8501, Japan
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16
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Chiereghin C, Robusto M, Mastrangelo A, Castorina P, Montini G, Giani M, Duga S, Asselta R, Soldà G. Alport syndrome cold cases: Missing mutations identified by exome sequencing and functional analysis. PLoS One 2017; 12:e0178630. [PMID: 28570636 PMCID: PMC5453569 DOI: 10.1371/journal.pone.0178630] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 05/16/2017] [Indexed: 12/30/2022] Open
Abstract
Alport syndrome (AS) is an inherited progressive renal disease caused by mutations in COL4A3, COL4A4, and COL4A5 genes. Despite simultaneous screening of these genes being widely available, mutation detection still remains incomplete in a non-marginal portion of patients. Here, we applied whole-exome sequencing (WES) in 3 Italian families negative after candidate-gene analyses. In Family 1, we identified a novel heterozygous intronic variant (c.2245-40A>G) -outside the conventionally screened candidate region for diagnosis- potentially disrupting COL4A5 exon29 splicing. Using a minigene-based approach in HEK293 cells we demonstrated that this variant abolishes exon29 branch site, causing exon skipping. Moreover, skewed X-inactivation of the c.2245-40A>G allele correlated with disease severity in heterozygous females. In Family 2, WES highlighted a novel COL4A5 hemizygous missense mutation (p.Gly491Asp), which segregates with the phenotype and impacts on a highly-conserved residue. Finally, in Family 3, we detected a homozygous 24-bp in-frame deletion in COL4A3 exon1 (NM_000091.4:c.30_53del:p.Val11_Leu18del or c.40_63del24:p.Leu14_Leu21del), which is ambiguously annotated in databases, although it corresponds to a recurrent AS mutation. Functional analyses showed that this deletion disrupts COL4A3 signal peptide, possibly altering protein secretion. In conclusion, WES -together with functional studies- was fundamental for molecular diagnosis in 3 AS families, highlighting pathogenic variants that escaped previous screenings.
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Affiliation(s)
- Chiara Chiereghin
- Department of Biomedical Sciences, Humanitas University, Rozzano, Milan, Italy
- Humanitas Clinical and Research Center, Rozzano, Milan, Italy
| | - Michela Robusto
- Department of Biomedical Sciences, Humanitas University, Rozzano, Milan, Italy
- Humanitas Clinical and Research Center, Rozzano, Milan, Italy
| | - Antonio Mastrangelo
- UOC Nefrologia Pediatrica, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Pierangela Castorina
- UO Audiologia, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milan, Italy
- Dipartimento di Scienze Cliniche e di Comunità, Università degli Studi di Milano, Milan, Italy
| | - Giovanni Montini
- UOC Nefrologia Pediatrica, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Marisa Giani
- UOC Nefrologia Pediatrica, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Stefano Duga
- Department of Biomedical Sciences, Humanitas University, Rozzano, Milan, Italy
- Humanitas Clinical and Research Center, Rozzano, Milan, Italy
| | - Rosanna Asselta
- Department of Biomedical Sciences, Humanitas University, Rozzano, Milan, Italy
- Humanitas Clinical and Research Center, Rozzano, Milan, Italy
| | - Giulia Soldà
- Department of Biomedical Sciences, Humanitas University, Rozzano, Milan, Italy
- Humanitas Clinical and Research Center, Rozzano, Milan, Italy
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17
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Fallerini C, Baldassarri M, Trevisson E, Morbidoni V, La Manna A, Lazzarin R, Pasini A, Barbano G, Pinciaroli AR, Garosi G, Frullanti E, Pinto AM, Mencarelli MA, Mari F, Renieri A, Ariani F. Alport syndrome: impact of digenic inheritance in patients management. Clin Genet 2017; 92:34-44. [PMID: 27859054 DOI: 10.1111/cge.12919] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 11/02/2016] [Accepted: 11/03/2016] [Indexed: 11/28/2022]
Abstract
Alport syndrome (ATS) is a genetically heterogeneous nephropathy with considerable phenotypic variability and different transmission patterns, including monogenic (X-linked/autosomal) and digenic inheritance (DI). Here we present a new series of families with DI and we discuss the consequences for genetic counseling and risk assessment. Out of five families harboring variants in more than one COL4 gene detected by next generation sequencing (NGS), minigene-splicing assay allowed us to identify four as true digenic. Two families showed COL4A3/A4 mutations in cis, mimicking an autosomal dominant inheritance with a more severe phenotype and one showed COL4A3/A4 mutations in trans, mimicking an autosomal recessive inheritance with a less severe phenotype. In a fourth family, a de novo mutation (COL4A5) combined with an inherited mutation (COL4A3) triggered a more severe phenotype. A fifth family, predicted digenic on the basis of silico tools, rather showed monogenic X-linked inheritance due to a hypomorphic mutation, in accordance with a milder phenotype. In conclusion, this study highlights the impact of DI in ATS and explains the associated atypical presentations. More complex inheritance should be therefore considered when reviewing prognosis and recurrence risks. On the other side, these findings emphasize the importance to accompany NGS with splicing assays in order to avoid erroneous identification of at risk members.
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Affiliation(s)
- C Fallerini
- Medical Genetics, University of Siena, Siena, Italy
| | - M Baldassarri
- Medical Genetics, University of Siena, Siena, Italy.,Genetica Medica, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - E Trevisson
- Department of Woman and Child Health, University of Padova, Padova, Italy.,Istituto di Ricerca Pediatria, IRP, Città della Speranza, Padova, Italy
| | - V Morbidoni
- Department of Woman and Child Health, University of Padova, Padova, Italy.,Istituto di Ricerca Pediatria, IRP, Città della Speranza, Padova, Italy
| | - A La Manna
- Department of Pediatrics, Second University of Napoli, Napoli, Italy
| | - R Lazzarin
- Nephrology and Dialysis, Ospedale San Giacomo Apostolo, Castelfranco Veneto, Italy
| | - A Pasini
- Nephrology and Pediatric Dialysis, Ospedale S. Orsola Malpighi, Bologna, Italy
| | - G Barbano
- Renal immunopathology, Istituto Giannina Gaslini, Genova, Italy
| | - A R Pinciaroli
- Nephrology and Dialysis, Azienda Ospedaliera Pugliese Ciaccio, Catanzaro, Italy
| | - G Garosi
- Nephrology, Dialysis and Transplantation, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - E Frullanti
- Medical Genetics, University of Siena, Siena, Italy
| | - A M Pinto
- Medical Genetics, University of Siena, Siena, Italy.,Genetica Medica, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - M A Mencarelli
- Genetica Medica, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - F Mari
- Medical Genetics, University of Siena, Siena, Italy.,Genetica Medica, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - A Renieri
- Medical Genetics, University of Siena, Siena, Italy.,Genetica Medica, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - F Ariani
- Medical Genetics, University of Siena, Siena, Italy.,Genetica Medica, Azienda Ospedaliera Universitaria Senese, Siena, Italy
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18
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Zhang Y, Wang F, Ding J, Zhang H, Liu X, Wang S, Xiao H, Yao Y, Liu J, Zhong X, Guan N, Su B, Wu G, Yu L. Long-term treatment by ACE inhibitors and angiotensin receptor blockers in children with Alport syndrome. Pediatr Nephrol 2016; 31:67-72. [PMID: 26248473 DOI: 10.1007/s00467-015-3184-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2015] [Revised: 07/21/2015] [Accepted: 07/23/2015] [Indexed: 01/11/2023]
Abstract
BACKGROUND The aim of this study was to analyze the long-term efficacy and safety of angiotensin-converting enzyme inhibitor (ACEi) and ACEi + angiotensin receptor blocker (ARB) treatments in a cohort of children with Alport syndrome (AS). METHODS This was a respective review of 79 Chinese children with AS who received ACEi alone or combined ACEi + ARB therapy. RESULTS The mean age of the pediatric patients with AS at onset of treatment was 8.6 ± 4.1 (range 1.5-16.3) years. The mean duration of follow-up was 2.5 ± 1.8 (range 0.5-7.8) years. For analysis, we separated the children into three groups according to proteinuria level before treatment, namely, <25, 25-50, and ≥50 mg/kg/day, respectively; after 1 year of treatment the proteinuria had decreased from 11.0 to 9.7 mg/kg/day, from 34.6 to 15.2 mg/kg/day, and from 73.0 to 50.0 mg/kg/day in each group, respectively. Proteinuria decreased significantly during the first 2 years of treatment and was stable from the third to fifth years of treatment. There was no statistically significant difference in the antiproteinuric effect of the ACEi and ACEi + ARB treatments in patients with severe or less severe mutations after 1 year of therapy. Five children stopped the ACEi + ARB treatment due to a decline in creatinine clearance. CONCLUSION Our findings demonstrate that early and long-term ACEi and ARB treatments in children with AS is efficient and well tolerated. The antiproteinuric effect of ACEi and ARB is of equal value in children with severe and less severe mutations in the COL4An gene.
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Affiliation(s)
- Yanqin Zhang
- Department of Pediatrics, Peking University First Hospital, No. 1, Xi An Men Da Jie, Beijing, 100034, People's Republic of China
| | - Fang Wang
- Department of Pediatrics, Peking University First Hospital, No. 1, Xi An Men Da Jie, Beijing, 100034, People's Republic of China
| | - Jie Ding
- Department of Pediatrics, Peking University First Hospital, No. 1, Xi An Men Da Jie, Beijing, 100034, People's Republic of China.
| | - Hongwen Zhang
- Department of Pediatrics, Peking University First Hospital, No. 1, Xi An Men Da Jie, Beijing, 100034, People's Republic of China
| | - Xiaoyu Liu
- Department of Pediatrics, Peking University First Hospital, No. 1, Xi An Men Da Jie, Beijing, 100034, People's Republic of China
| | - Suxia Wang
- Department of Electron Microscopy, Peking University First Hospital, Beijing, China
| | - Huijie Xiao
- Department of Pediatrics, Peking University First Hospital, No. 1, Xi An Men Da Jie, Beijing, 100034, People's Republic of China
| | - Yong Yao
- Department of Pediatrics, Peking University First Hospital, No. 1, Xi An Men Da Jie, Beijing, 100034, People's Republic of China
| | - Jingcheng Liu
- Department of Pediatrics, Peking University First Hospital, No. 1, Xi An Men Da Jie, Beijing, 100034, People's Republic of China
| | - Xuhui Zhong
- Department of Pediatrics, Peking University First Hospital, No. 1, Xi An Men Da Jie, Beijing, 100034, People's Republic of China
| | - Na Guan
- Department of Pediatrics, Peking University First Hospital, No. 1, Xi An Men Da Jie, Beijing, 100034, People's Republic of China
| | - Baige Su
- Department of Pediatrics, Peking University First Hospital, No. 1, Xi An Men Da Jie, Beijing, 100034, People's Republic of China
| | - Guohong Wu
- Department of Pediatrics, Peking University First Hospital, No. 1, Xi An Men Da Jie, Beijing, 100034, People's Republic of China
| | - Lixia Yu
- Department of Pediatrics, Peking University First Hospital, No. 1, Xi An Men Da Jie, Beijing, 100034, People's Republic of China
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19
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Lin F, Bian F, Zou J, Wu X, Shan J, Lu W, Yao Y, Jiang G, Gale DP. Whole exome sequencing reveals novel COL4A3 and COL4A4 mutations and resolves diagnosis in Chinese families with kidney disease. BMC Nephrol 2014; 15:175. [PMID: 25381091 PMCID: PMC4233041 DOI: 10.1186/1471-2369-15-175] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Accepted: 10/28/2014] [Indexed: 01/01/2023] Open
Abstract
Background Collagen IV-related nephropathies, including thin basement membrane nephropathy and Alport Syndrome (AS), are caused by defects in the genes COL4A3, COL4A4 and COL4A5. Diagnosis of these conditions can be hindered by variable penetrance and the presence of non-specific clinical or pathological features. Methods Three families with unexplained inherited kidney disease were recruited from Shanghai, China. Whole exome sequencing (WES) was performed in the index case from each family and co-segregation of candidate pathogenic mutations was tested by Sanger sequencing. Results We identified COL4A4 missense variants [c.G2636A (p.Gly879Glu) and c.C4715T (p.Pro1572Leu)] in the 21-year-old male proband from family 1, who had been diagnosed with mesangial proliferative nephropathy at age 14. COL4A4 c.G2636A, a novel variant, co-segregated with renal disease among maternal relatives. COL4A4 c.C4715T has previously been associated with autosomal recessive AS and was inherited from his clinically unaffected father. In family 2, a novel COL4A3 missense mutation c.G2290A (p.Gly997Glu) was identified in a 45-year-old male diagnosed with focal segmental glomerulosclerosis and was present in all his affected family members, who exhibited disease ranging from isolated microscopic hematuria to end stage renal disease (ESRD). In family 3, ESRD occurred in both male and females who were found to harbor a known AS-causing COL4A5 donor splice site mutation (c.687 + 1G > A). None of these variants were detected among 100 healthy Chinese individuals. Conclusion WES identified 2 novel and 2 known pathogenic COL4A3/COL4A4/COL4A5 mutations in 3 families with previously unexplained inherited kidney disease. These findings highlight the clinical range of collagen IV-related nephropathies and resolved diagnostic confusion arising from atypical or incomplete clinical/histological findings, allowing appropriate counselling and treatment advice to be given. Electronic supplementary material The online version of this article (doi:10.1186/1471-2369-15-175) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | | | | | | | | | | | | | - Gengru Jiang
- Department of Nephrology, Xin Hua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
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Oka M, Nozu K, Kaito H, Fu XJ, Nakanishi K, Hashimura Y, Morisada N, Yan K, Matsuo M, Yoshikawa N, Vorechovsky I, Iijima K. Natural history of genetically proven autosomal recessive Alport syndrome. Pediatr Nephrol 2014; 29:1535-44. [PMID: 24633401 DOI: 10.1007/s00467-014-2797-4] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2014] [Revised: 02/18/2014] [Accepted: 02/21/2014] [Indexed: 12/17/2022]
Abstract
BACKGROUND Autosomal recessive Alport syndrome (ARAS) is a rare hereditary disease caused by homozygous or compound heterozygous mutations in either the COL4A3 or COL4A4 genes. Failure to diagnose ARAS cases is common, even if detailed clinical and pathological examinations are carried out. As the mutation detection rate for ARAS is unsatisfactory, we sought to develop more reliable diagnostic methods and provide a better description of the clinicopathological characteristics of this disorder. METHODS A retrospective analysis of 30 genetically diagnosed patients with ARAS in 24 pedigrees was conducted. The mutation detection strategy comprised three steps: (1) genomic DNA analysis using polymerase chain reaction (PCR) and direct sequencing; (2) mRNA analysis using reverse transcription (RT)-PCR to detect RNA processing abnormalities; (3) semi-quantitative PCR using capillary electrophoresis to detect large heterozygous deletions. RESULTS Using the three-step analysis, we identified homozygous or compound heterozygous mutations in all patients. Interestingly, 20% of our ARAS patients showed normal expression of α5 in kidney tissue. The median age of developing end-stage renal disease was 21 years. CONCLUSIONS The strategy described in this study improves the diagnosis for ARAS families. Although immunohistochemical analysis of α5 can provide diagnostic information, normal distribution does not exclude the diagnosis of ARAS.
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Affiliation(s)
- Masafumi Oka
- Department of Pediatrics, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo, Kobe, Hyogo, 6500017, Japan
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A mouse Col4a4 mutation causing Alport glomerulosclerosis with abnormal collagen α3α4α5(IV) trimers. Kidney Int 2014; 85:1461-8. [PMID: 24522496 PMCID: PMC4040157 DOI: 10.1038/ki.2013.493] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Revised: 09/11/2013] [Accepted: 10/03/2013] [Indexed: 12/31/2022]
Abstract
A spontaneous mutation termed bilateral wasting kidneys (bwk) was identified in a colony of NONcNZO recombinant inbred mice. These mice exhibit a rapid increase of urinary albumin at an early age associated with glomerulosclerosis, interstitial nephritis, and tubular atrophy. The mutation was mapped to a location on chromosome 1 containing the Col4a3 and Col4a4 genes, for which mutations in the human orthologs cause the hereditary nephritis Alport syndrome. DNA sequencing identified a G-to-A mutation in the conserved GT splice donor of Col4a4 intron 30, resulting in skipping of exon 30 but maintaining the mRNA reading frame. Protein analyses showed that mutant collagen α3α4α5(IV) trimers were secreted and incorporated into the glomerular basement membrane (GBM), but levels were low, and GBM lesions typical of Alport syndrome were observed. Moving the mutation into the more renal damage-prone DBA/2J and 129S1/SvImJ backgrounds revealed differences in albuminuria and its rate of increase, suggesting an interaction between the Col4a4 mutation and modifier genes. This novel mouse model of Alport syndrome is the only one shown to accumulate abnormal collagen α3α4α5(IV) in the GBM, as also found in a subset of Alport patients. These mice will be valuable for testing potential therapies, for understanding abnormal collagen IV structure and assembly, and for gaining better insights into the mechanisms leading to Alport syndrome, and to the variability in the age of onset and associated phenotypes.
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Webb BD, Brandt T, Liu L, Jalas C, Liao J, Fedick A, Linderman MD, Diaz GA, Kornreich R, Trachtman H, Mehta L, Edelmann L. A founder mutation in COL4A3 causes autosomal recessive Alport syndrome in the Ashkenazi Jewish population. Clin Genet 2013; 86:155-60. [PMID: 23927549 DOI: 10.1111/cge.12247] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Revised: 08/01/2013] [Accepted: 08/02/2013] [Indexed: 11/30/2022]
Abstract
Alport syndrome is an inherited progressive nephropathy arising from mutations in the type IV collagen genes, COL4A3, COL4A4, and COL4A5. Symptoms also include sensorineural hearing loss and ocular lesions. We determined the molecular basis of Alport syndrome in a non-consanguineous Ashkenazi Jewish family with multiple affected females using linkage analysis and next generation sequencing. We identified a homozygous COL4A3 mutation, c.40_63del, in affected individuals with mutant alleles inherited from each parent on partially conserved haplotypes. Large-scale population screening of 2017 unrelated Ashkenazi Jewish samples revealed a carrier frequency of 1 in 183 indicating that COL4A3 c.40_63del is a founder mutation which may be a common cause of Alport syndrome in this population. Additionally, we determined that heterozygous mutation carriers in this family do not meet criteria for a diagnosis of Thin Basement Membrane Nephropathy and concluded that carriers of c.40_63del are not likely to develop benign familial hematuria.
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Affiliation(s)
- B D Webb
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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Uzak AS, Tokgoz B, Dundar M, Tekin M. A novel COL4A3 mutation causes autosomal-recessive Alport syndrome in a large Turkish family. Genet Test Mol Biomarkers 2013; 17:260-4. [PMID: 23297803 DOI: 10.1089/gtmb.2012.0340] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Alport syndrome (AS) is a genetically heterogeneous disorder that is characterized by hematuria, progressive renal failure typically resulting in end-stage renal disease, sensorineural hearing loss, and variable ocular abnormalities. Only 15% of cases with AS are autosomal recessive and are caused by mutations in the COL4A3 or COL4A4 genes, encoding type IV collagen. METHODS Clinical data in a large consanguineous family with four affected members were reviewed, and genomic DNA was extracted. For mapping, 15 microsatellite markers flanking COL4A3, COL4A4, and COL4A5 in 16 family members were typed. For mutation screening, all coding exons of COL4A3 were polymerase chain reaction- amplified and Sanger-sequenced from genomic DNA. RESULTS The disease locus was mapped to chromosome 2q36.3, where COL4A3 and COL4A4 reside. Sanger sequencing revealed a novel mis-sense mutation (c.2T>C; p.M1T) in exon 1 of COL4A3. The identified nucleotide change was not found in 100 healthy ethnicity-matched controls via Sanger sequencing. CONCLUSIONS We present a large consanguineous Turkish family with AS that was found to have a COL4A3 mutation as the cause of the disease. Although the relationship between the various genotypes and phenotypes in AS has not been fully elucidated, detailed clinical and molecular analyses are helpful for providing data to be used in genetic counseling. It is important to identify new mutations to clarify their clinical importance, to assess the prognosis of the disease, and to avoid renal biopsy for final diagnosis.
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Affiliation(s)
- Asli Subasioglu Uzak
- Department of Medical Genetics, Erciyes University School of Medicine, Kayseri, Turkey
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