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Yanus GA, Suspitsin EN, Imyanitov EN. The Spectrum of Disease-Associated Alleles in Countries with a Predominantly Slavic Population. Int J Mol Sci 2024; 25:9335. [PMID: 39273284 PMCID: PMC11394759 DOI: 10.3390/ijms25179335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2024] [Revised: 08/21/2024] [Accepted: 08/25/2024] [Indexed: 09/15/2024] Open
Abstract
There are more than 260 million people of Slavic descent worldwide, who reside mainly in Eastern Europe but also represent a noticeable share of the population in the USA and Canada. Slavic populations, particularly Eastern Slavs and some Western Slavs, demonstrate a surprisingly high degree of genetic homogeneity, and, consequently, remarkable contribution of recurrent alleles associated with hereditary diseases. Along with pan-European pathogenic variants with clearly elevated occurrence in Slavic people (e.g., ATP7B c.3207C>A and PAH c.1222C>T), there are at least 52 pan-Slavic germ-line mutations (e.g., NBN c.657_661del and BRCA1 c.5266dupC) as well as several disease-predisposing alleles characteristic of the particular Slavic communities (e.g., Polish SDHD c.33C>A and Russian ARSB c.1562G>A variants). From a clinical standpoint, Slavs have some features of a huge founder population, thus providing a unique opportunity for efficient genetic studies.
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Affiliation(s)
- Grigoriy A Yanus
- Laboratory of Molecular Diagnostics, St. Petersburg State Pediatric Medical University, 194100 St. Petersburg, Russia
| | - Evgeny N Suspitsin
- Department of Medical Genetics, St. Petersburg State Pediatric Medical University, 194100 St. Petersburg, Russia
- Department of Tumor Growth Biology, N.N. Petrov Institute of Oncology, 197758 St. Petersburg, Russia
| | - Evgeny N Imyanitov
- Department of Medical Genetics, St. Petersburg State Pediatric Medical University, 194100 St. Petersburg, Russia
- Department of Tumor Growth Biology, N.N. Petrov Institute of Oncology, 197758 St. Petersburg, Russia
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2
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Wang D, Pan M, Li H, Li M, Li P, Xiong F, Xiao H. Four novel mutations identified in the COL4A3, COL4A4 and COL4A5 genes in 10 families with Alport syndrome. BMC Med Genomics 2024; 17:181. [PMID: 38978054 PMCID: PMC11229269 DOI: 10.1186/s12920-024-01953-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Accepted: 06/27/2024] [Indexed: 07/10/2024] Open
Abstract
BACKGROUND Alport syndrome (AS) is an inherited nephropathy caused by mutations in the type IV collagen genes. It is clinically characterized by damage to the eyes, ears and kidneys. Diagnosis of AS is hampered by its atypical clinical picture, particularly when the typical features, include persistent hematuria and microscopic changes in the glomerular basement membrane (GBM), are the only clinical manifestations in the patient. METHODS We screened 10 families with suspected AS using whole exome sequencing (WES) and analyzed the harmfulness, conservation, and protein structure changes of mutated genes. In further, we performed in vitro functional analysis of two missense mutations in the COL4A5 gene (c.2359G > C, p.G787R and c.2605G > A, p.G869R). RESULTS We identified 11 pathogenic variants in the type IV collagen genes (COL4A3, COL4A4 and COL4A5). These pathogenic variants include eight missense mutations, two nonsense mutations and one frameshift mutation. Notably, Family 2 had digenic mutations in the COL4A3 (p.G1170A) and UMOD genes (p.M229K). Family 3 had a digenic missense mutation (p.G997E) in COL4A3 and a frameshift mutation (p.P502L fs*151) in COL4A4. To our knowledge, four of the 11 mutations are novel mutations. In addition, we found that COL4A5 mutation relation mRNA levels were significantly decreased in HEK 293 T cell compared to control, while the cellular localization remained the same. CONCLUSIONS Our research expands the spectrum of COL4A3-5 pathogenic variants, which is helpful for clinical and scientific research.
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Affiliation(s)
- Duocai Wang
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong, China
| | - Meize Pan
- Department of Nephrology, Peking University Shenzhen Hospital, Futian, Shenzhen, Guangdong, 518036, China
| | - Hang Li
- Department of Urology, Peking University Shenzhen Hospital, Futian, Shenzhen, Guangdong, China
| | - Minchun Li
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong, China
| | - Ping Li
- Department of Pathology, Peking University Shenzhen Hospital, Futian, Shenzhen, Guangdong, China
| | - Fu Xiong
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong, China.
- Guangdong Provincial Key Laboratory of Single Cell Technology and Application, Guangzhou, Guangdong, China.
- Department of Fetal Medicine and Prenatal Diagnosis, Zhujiang Hospital, Southern Medical University, Guangzhou, China.
| | - Hongbo Xiao
- Department of Nephrology, Peking University Shenzhen Hospital, Futian, Shenzhen, Guangdong, 518036, China.
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Wang SX, Streit A. Shared features in ear and kidney development - implications for oto-renal syndromes. Dis Model Mech 2024; 17:dmm050447. [PMID: 38353121 PMCID: PMC10886756 DOI: 10.1242/dmm.050447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2024] Open
Abstract
The association between ear and kidney anomalies has long been recognized. However, little is known about the underlying mechanisms. In the last two decades, embryonic development of the inner ear and kidney has been studied extensively. Here, we describe the developmental pathways shared between both organs with particular emphasis on the genes that regulate signalling cross talk and the specification of progenitor cells and specialised cell types. We relate this to the clinical features of oto-renal syndromes and explore links to developmental mechanisms.
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Affiliation(s)
- Scarlet Xiaoyan Wang
- Centre for Craniofacial and Regenerative Biology, King's College London, London SE1 9RT, UK
| | - Andrea Streit
- Centre for Craniofacial and Regenerative Biology, King's College London, London SE1 9RT, UK
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Liang L, Wu H, Cai Z, Zhao J. Genetic and molecular dynamics analysis of two variants of the COL4A5 gene causing Alport syndrome. BMC Med Genomics 2023; 16:192. [PMID: 37596645 PMCID: PMC10436629 DOI: 10.1186/s12920-023-01623-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 07/31/2023] [Indexed: 08/20/2023] Open
Abstract
BACKGROUND Alport syndrome (AS; OMIM#308,940) is a hereditary kidney disease that progresses over time and is distinguished by hearing loss and ocular irregularities. The syndrome has three subtypes, namely X-linked (XL; OMIM#301,050), autosomal recessive (AR; OMIM#203,780), and autosomal dominant (AD; OMIM#104,200), which are categorized based on their respective modes of inheritance. XLAS is attributed to a pathogenic variant in the COL4A5 (OMIM*303,630) gene, which encodes the α5(IV) chain of type IV collagen (Col-IV). In contrast, ADAS and ARAS are the result of variants in the COL4A3 (OMIM*120,070) and COL4A4 (OMIM*120,131) genes, which encode the α3(IV) and α4(IV) chains of Col-IV, respectively. Typically, the diagnosis of AS necessitates hereditary or pathological assessments. The determination of splicing variants as pathogenic or non-pathogenic based on gene sequencing outcomes is challenging. METHODS In this study, we conducted exome sequencing and Sanger sequencing on two unrelated Chinese patients with AS. We identified a deletion variant c.4414delG in the COL4A5 gene and a splicing variant c.4298-20T > A in the same gene. In order to ascertain the impact of c.4298-20T > A on the synthesis of COL4A5 mRNA, we performed experiments involving minigene splicing. Additionally, we predicted the ability of these two variants to affect triple helix formation of α345(IV) using molecular dynamics methods. RESULTS The c.4414delG deletion variant caused a change in the genetic code of the COL4A5 gene. Specifically, it caused a shift in codon 1472 from encoding aspartate to encoding methionine. This shift resulted in a change of 75 amino acids in the protein sequence, ultimately leading to an early stop codon. This premature stop codon caused the production of a truncated α5(IV) chain with a predicted protein effect of p.D1472Mfs. The mRNA of the COL4A5 gene experienced intron 46 retention due to the splicing variant c.4298-20T > A, leading to the inclusion of six additional amino acids between amino acids 1432 and 1433 of the α5(IV) chain. This variant is predicted to have a protein effect of p.(P1432_G1433insDYFVEI). The impact of two variants, c.4414delG and c.4298-20T > A, on the aggregation region for α3(IV), α4(IV), and α5(IV) trimerisation were studied using molecular dynamics simulations. Results showed that the deletion variant c.4414delG had a significantly stronger disruption on NC1, compared to the splicing variant c.4298-20T > A. This difference in impact is consistent with the varying clinical phenotypes observed in the two patients. Based on the American College of Medical Genetics and Genomics (ACMG) classification criteria and guidelines for genetic variants, the deletion variant c.4414delG was rated as pathogenic while the splicing variant c.4298-20T > A was rated as likely-pathogenic. CONCLUSION Our study has identified two novel pathogenic loci, the deletion variant c.4414delG and the splicing variant c.4298-20T > A, associated with XLAS. This finding expands the genetic spectrum of XLAS. We suggest that molecular dynamics can effectively model the effect of genetic variation on α345(IV) trimerization, which may offer valuable insights into the mechanisms of XLAS pathogenesis.
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Affiliation(s)
- Lei Liang
- Center for Prenatal Diagnosis and Medical Genetics, Affiliated Hospital of Inner Mongolia Medical University, Hohhot, 010015, PR China
| | - Haotian Wu
- School of Public Health, Inner Mongolia Medical University, Hohhot, 010015, PR China
| | - Zeyu Cai
- Department of Nephrology, Affiliated Hospital of Inner Mongolia Medical University, Hohhot, 010015, PR China
| | - Jianrong Zhao
- Department of Nephrology, Affiliated Hospital of Inner Mongolia Medical University, Hohhot, 010015, PR China.
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5
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Gao Y, Yuan L, Yuan J, Yang Y, Wang J, Chen Y, Zhang H, Ai Y, Deng H. Identification of COL4A4 variants in Chinese patients with familial hematuria. Front Genet 2023; 13:1064491. [PMID: 36699462 PMCID: PMC9868811 DOI: 10.3389/fgene.2022.1064491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Accepted: 12/15/2022] [Indexed: 01/11/2023] Open
Abstract
Background: Benign familial hematuria and Alport syndrome are common causes of familial hematuria among children and young adults, which are attributable to variants in the collagen type IV alpha chain genes, COL4A3, COL4A4, or COL4A5. The study was conducted to identify the underlying genetic causes in patients with familial hematuria. Methods: Two unrelated Han-Chinese pedigrees with familial hematuria were recruited for this study. Whole exome sequencing was combined with in silico analysis to identify potential genetic variants, followed by variant confirmation by Sanger sequencing. Reverse transcription, PCR, and Sanger sequencing were performed to evaluate the effect of the detected splicing variant on mRNA splicing. Results: A novel heterozygous splicing c.595-1G>A variant and a known heterozygous c.1715G>C variant in the collagen type IV alpha 4 chain gene (COL4A4) were identified and confirmed in patients of pedigree 1 and pedigree 2, respectively. Complementary DNA analysis indicated this splicing variant could abolish the canonical splice acceptor site and cause a single nucleotide deletion of exon 10, which was predicted to produce a truncated protein. Conclusions: The two COL4A4 variants, c.595-1G>A variant and c.1715G>C (p.Gly572Ala) variant, were identified as the genetic etiologies of two families with familial hematuria, respectively. Our study broadened the variant spectrum of the COL4A4 gene and explained the possible pathogenesis, which will benefit clinical management and genetic counseling.
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Affiliation(s)
- Yanan Gao
- Health Management Center, The Third Xiangya Hospital, Central South University, Changsha, China,Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Lamei Yuan
- Health Management Center, The Third Xiangya Hospital, Central South University, Changsha, China,Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China,Disease Genome Research Center, Central South University, Changsha, China
| | - Jinzhong Yuan
- Department of Nephrology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Yan Yang
- Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Jiangang Wang
- Health Management Center, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Yong Chen
- National Health Committee Key Laboratory of Birth Defects for Research and Prevention, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, China
| | - Hao Zhang
- Department of Nephrology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Yinze Ai
- Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Hao Deng
- Health Management Center, The Third Xiangya Hospital, Central South University, Changsha, China,Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China,Disease Genome Research Center, Central South University, Changsha, China,*Correspondence: Hao Deng,
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García-Aznar JM, De la Higuera L, Besada Cerecedo L, Gandiaga NP, Vega AI, Fernández-Fresnedo G, González-Lamuño D. New Insights into Renal Failure in a Cohort of 317 Patients with Autosomal Dominant Forms of Alport Syndrome: Report of Two Novel Heterozygous Mutations in COL4A3. J Clin Med 2022; 11:jcm11164883. [PMID: 36013122 PMCID: PMC9409901 DOI: 10.3390/jcm11164883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 07/27/2022] [Accepted: 08/12/2022] [Indexed: 11/24/2022] Open
Abstract
Alport syndrome (AS) is a clinically and genetically heterogeneous disorder with a wide phenotypic spectrum, onset, and progression. X-linked AS (XLAS) and autosomal recessive AS (ARAS) are severe conditions, whereas the severity of autosomal dominant AS (ADAS) may vary from benign familial hematuria to progressive renal disease with extra-renal manifestations. In this study, we collated information from the literature and analyzed a cohort of 317 patients with ADAS carrying heterozygous disease-causing mutations in COL4A3/4 including four patients from two unrelated families who carried two novel variants in COL4A3. Regarding the age of onset of the disease, 80% of patients presented urinalysis alterations (microhematuria, hematuria, and/or proteinuria) before the age of 40 years. The cumulative probability of suffering adverse renal events was mainly observed between 30 and 70 years, without statistical differences between COL4A3 and COL4A4. We observed statistically significant differences between the sexes in the age of developing ESKD in cases affected by mutations in COL4A3/4 (p value = 0.0097), suggesting that males begin experiencing earlier deterioration of renal function than women. This study supports the importance of follow-up in young patients who harbor pathogenic mutations in COL4A3/4. We update the knowledge of ADAS, highlighting differences in the progression of the disease between males and females.
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Affiliation(s)
| | | | | | - Nerea Paz Gandiaga
- Servicio de Genética, Hospital Universitario Marqués de Valdecilla, 39008 Santander, Spain
| | - Ana Isabel Vega
- Servicio de Genética, Hospital Universitario Marqués de Valdecilla, 39008 Santander, Spain
| | - Gema Fernández-Fresnedo
- Servicio de Nefrología, Hospital Universitario Marqués de Valdecilla, 39008 Santander, Spain
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Cerkauskaite A, Savige J, Janonyte K, Jeremiciute I, Miglinas M, Kazenaite E, Laurinavicius A, Strupaite-Sileikiene R, Vainutiene V, Burnyte B, Jankauskiene A, Rolfs A, Bauer P, Schröder S, Cerkauskiene R. Identification of 27 Novel Variants in Genes COL4A3, COL4A4, and COL4A5 in Lithuanian Families With Alport Syndrome. Front Med (Lausanne) 2022; 9:859521. [PMID: 35419377 PMCID: PMC8995700 DOI: 10.3389/fmed.2022.859521] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 03/02/2022] [Indexed: 11/13/2022] Open
Abstract
Introduction: Alport syndrome (AS) is an inherited disorder characterized by hematuria, proteinuria, and kidney function impairment, and frequently associated with extrarenal manifestations. Pathogenic variants in COL4A5 usually cause X-linked Alport syndrome (XLAS), whereas those in the COL4A3 or COL4A4 genes are associated with autosomal dominant (AD) or recessive (AR) inheritance. To date, more than 3000 different disease-causing variants in COL4A5, COL4A3, and COL4A4 have been identified. The aim of this study was to evaluate the clinical and genetic spectrum of individuals with novel, pathogenic or likely pathogenic variants in the COL4A3-A5 genes in a previously unstudied cohort. Methods In this study molecular analysis by next generation sequencing (NGS) was performed on individuals from a Lithuanian cohort, with suspected AS. The presence of AS was assessed by reviewing clinical evidence of hematuria, proteinuria, chronic kidney disease (CKD), kidney failure (KF), a family history of AS or persistent hematuria, and specific histological lesions in the kidney biopsy such as thinning or lamellation of the glomerular basement membrane (GBM). Clinical, genetic, laboratory, and pathology data were reviewed. The novelty of the COL4A3-A5 variants was confirmed in the genetic variant databases (Centogene, Franklin, ClinVar, Varsome, InterVar). Only undescribed variants were included in this study. Results Molecular testing of 171 suspected individuals led to the detection of 99 individuals with 44 disease causing variants including 27, previously undescribed changes, with the frequency of 9/27 (33,3%) in genes COL4A5, COL4A3 and COL4A4 equally. Three individuals were determined as having digenic AS causing variants: one in COL4A3 and COL4A4, two in COL4A4 and COL4A5. The most prevalent alterations in genes COL4A3-5 were missense variants (n = 19), while splice site, frameshift, unknown variant and stop codon changes were detected more in genes COL4A4 and COL4A5 and accounted for 3, 3, 1 and 1 of all novel variants, respectively. Conclusion Genotype-phenotype correlation analysis suggested that some variants demonstrated intra-familial phenotypic variability. These novel variants represented more than half of all the variants found in a cohort of 171 individuals from 109 unrelated families who underwent testing. Our study expands the knowledge of the genetic and phenotypic spectrum for AS.
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Affiliation(s)
- Agne Cerkauskaite
- Institute of Biomedical Sciences, Faculty of Medicine, Vilnius University, Vilnius, Lithuania
| | - Judy Savige
- Department of Medicine (Melbourne Health and Northern Health), Royal Melbourne Hospital, The University of Melbourne, Parkville, VIC, Australia
| | | | | | - Marius Miglinas
- Institute of Clinical Medicine, Faculty of Medicine, Vilnius University, Vilnius, Lithuania
| | - Edita Kazenaite
- Institute of Biomedical Sciences, Faculty of Medicine, Vilnius University, Vilnius, Lithuania
| | - Arvydas Laurinavicius
- Institute of Biomedical Sciences, Faculty of Medicine, Vilnius University, Vilnius, Lithuania
| | | | - Vija Vainutiene
- Centre of Ear, Nose and Throat Diseases, Vilnius University Hospital Santaros Klinikos, Vilnius, Lithuania
| | - Birute Burnyte
- Institute of Biomedical Sciences, Faculty of Medicine, Vilnius University, Vilnius, Lithuania
| | - Augustina Jankauskiene
- Institute of Clinical Medicine, Faculty of Medicine, Vilnius University, Vilnius, Lithuania
| | - Arndt Rolfs
- Albrecht Kossel Institute for Neuroregeneration, University of Rostock, Rostock, Germany
| | | | | | - Rimante Cerkauskiene
- Institute of Clinical Medicine, Faculty of Medicine, Vilnius University, Vilnius, Lithuania
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8
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Gibson J, Fieldhouse R, Chan MM, Sadeghi-Alavijeh O, Burnett L, Izzi V, Persikov AV, Gale DP, Storey H, Savige J. Prevalence Estimates of Predicted Pathogenic COL4A3-COL4A5 Variants in a Population Sequencing Database and Their Implications for Alport Syndrome. J Am Soc Nephrol 2021; 32:2273-2290. [PMID: 34400539 PMCID: PMC8729840 DOI: 10.1681/asn.2020071065] [Citation(s) in RCA: 85] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 05/05/2021] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND The reported prevalence of Alport syndrome varies from one in 5000 to one in 53,000 individuals. This study estimated the frequencies of predicted pathogenic COL4A3-COL4A5 variants in sequencing databases of populations without known kidney disease. METHODS Predicted pathogenic variants were identified using filtering steps based on the ACMG/AMP criteria, which considered collagen IV α3-α5 position 1 Gly to be critical domains. The population frequencies of predicted pathogenic COL4A3-COL4A5 variants were then determined per mean number of sequenced alleles. Population frequencies for compound heterozygous and digenic combinations were calculated from the results for heterozygous variants. RESULTS COL4A3-COL4A5 variants resulting in position 1 Gly substitutions were confirmed to be associated with hematuria (for each, P<0.001). Predicted pathogenic COL4A5 variants were found in at least one in 2320 individuals. p.(Gly624Asp) represented nearly half (16 of 33, 48%) of the variants in Europeans. Most COL4A5 variants (54 of 59, 92%) had a biochemical feature that potentially mitigated the clinical effect. The predicted pathogenic heterozygous COL4A3 and COL4A4 variants affected one in 106 of the population, consistent with the finding of thin basement membrane nephropathy in normal donor kidney biopsy specimens. Predicted pathogenic compound heterozygous variants occurred in one in 88,866 individuals, and digenic variants in at least one in 44,793. CONCLUSIONS The population frequencies for Alport syndrome are suggested by the frequencies of predicted pathogenic COL4A3-COL4A5 variants, but must be adjusted for the disease penetrance of individual variants and for the likelihood of already diagnosed disease and non-Gly substitutions. Disease penetrance may depend on other genetic and environmental factors.
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Affiliation(s)
- Joel Gibson
- The University of Melbourne Department of Medicine, Melbourne Health and Northern Health, Royal Melbourne Hospital, Parkville, Victoria, Australia
| | - Rachel Fieldhouse
- Kinghorn Centre for Clinical Genomics, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia
| | - Melanie M.Y. Chan
- Department of Renal Medicine, University College London, London, United Kingdom,Genomics England, Queen Mary University of London, London, United Kingdom
| | - Omid Sadeghi-Alavijeh
- Department of Renal Medicine, University College London, London, United Kingdom,Genomics England, Queen Mary University of London, London, United Kingdom
| | - Leslie Burnett
- Kinghorn Centre for Clinical Genomics, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia
| | - Valerio Izzi
- Center for Cell-Matrix Research and Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Anton V. Persikov
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey
| | - Daniel P. Gale
- Department of Renal Medicine, University College London, London, United Kingdom,Genomics England, Queen Mary University of London, London, United Kingdom
| | - Helen Storey
- Molecular Genetics, Viapath Laboratories, Guy’s Hospital, London, United Kingdom
| | - Judy Savige
- The University of Melbourne Department of Medicine, Melbourne Health and Northern Health, Royal Melbourne Hospital, Parkville, Victoria, Australia
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Wang FM, Yang Y, Zhang XL, Wang YL, Tu Y, Liu BC, Wang B. Combination of a Novel Genetic Variant in CFB Gene and a Pathogenic Variant in COL4A5 Gene in a Sibling Renal Disease: A Case Report. Front Genet 2021; 12:690952. [PMID: 34349783 PMCID: PMC8326751 DOI: 10.3389/fgene.2021.690952] [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: 04/07/2021] [Accepted: 06/07/2021] [Indexed: 12/02/2022] Open
Abstract
Complement factor B (CFB) variants have been described to play a causative role in auto-immune associated C3 glomerulopathy (C3G) and/or atypical hemolytic uremic syndrome (aHUS) by affecting the dysregulations of alternative pathway activation. However, CFB variant concomitant with COL4A5 variant is scarce. Here, we depict two intriguing cases with concurrent novel heterozygosity for CFB c.2054_2057del (p.Ser687Profs∗16) variant and a previous reported COL4A5 c.2999G > T (p.Gly1000Val) variant in a pair of siblings. The clinical feature of either paternal CFB variant or maternal COL4A5 variant is just mild microscopic hematuria. Interestingly, their two children with paternal CFB c.2054_2057del (p.Ser687Profs∗16) variant and maternal COL4A5 c.2999G > T (p.Gly1000Val) variant presented with massive proteinuria, hematuria, and progressive renal failure with poor treatment response. Moreover, complement pathway activation in renal tissue further supports and strengthens the pathogenic role of CFB variant in the development of renal injury in the presence of COL4A5 variant. In conclusion, the rare sibling cases highlight that the extension of genetic analyses in the proband is helpful for the diagnosis and understanding of some family cluster renal diseases.
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Affiliation(s)
- Feng-Mei Wang
- Institute of Nephrology, Zhongda Hospital, Southeast University School of Medicine, Nanjing, China
| | - Yan Yang
- Institute of Nephrology, Zhongda Hospital, Southeast University School of Medicine, Nanjing, China
| | - Xiao-Liang Zhang
- Institute of Nephrology, Zhongda Hospital, Southeast University School of Medicine, Nanjing, China
| | - Yan-Li Wang
- Institute of Nephrology, Zhongda Hospital, Southeast University School of Medicine, Nanjing, China
| | - Yan Tu
- Institute of Nephrology, Zhongda Hospital, Southeast University School of Medicine, Nanjing, China
| | - Bi-Cheng Liu
- Institute of Nephrology, Zhongda Hospital, Southeast University School of Medicine, Nanjing, China
| | - Bin Wang
- Institute of Nephrology, Zhongda Hospital, Southeast University School of Medicine, Nanjing, China
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10
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Novel Mutations of COL4A5 Identified in Chinese Families with X-Linked Alport Syndrome and Literature Review. BIOMED RESEARCH INTERNATIONAL 2021; 2021:6664973. [PMID: 33748275 PMCID: PMC7943288 DOI: 10.1155/2021/6664973] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Revised: 02/01/2021] [Accepted: 02/20/2021] [Indexed: 11/18/2022]
Abstract
Alport syndrome (AS) is an inherited kidney disease caused by defects in type IV collagen, which is characterized by hematuria, progressive nephritis or end-stage renal disease (ESRD), hearing loss, and occasionally ocular lesions. Approximately 80% of AS cases are caused by X-linked mutations in the COL4A5 gene. This study explored novel deletion and missense mutations in COL4A5 responsible for renal disorder in two Han Chinese families. In pedigree 1, the five male patients all had ESRD at a young age, while the affected female members only presented with microscopic hematuria. Whole exome sequencing and Sanger sequencing identified a novel frameshift deletion mutation (c.422_428del, p.Leu142Valfs∗11) in exon 7 of COL4A5. In pedigree 2, the 16-year-old male proband had elevated serum creatinine (309 μmol/L) without extrarenal manifestations, while his mother only manifested with hematuria. A missense mutation (c.476G>T, p.Gly159Val) was found in exon 9 of the COL4A5 gene. Neither of these mutations was present in the Exome Variant Server of the NHLBI-ESP database, nor was it found in the ExAC or 1000 Genomes databases. Through the literature review, it was found that male Chinese patients with X-linked AS carried COL4A5 deletion or missense mutations had a more severe phenotype than female patients, particularly in proteinuria and impaired renal function. Compared to male patients with missense mutations, patients in whom deletion mutations were found were more likely to progress to ESRD (15.4% vs. 36.0%, P = 0.041). This study identified two novel COL4A5 mutations in Chinese families with X-linked AS, expanded the mutational spectrum of the COL4A5 gene, and presented findings that are significant for the screening and genetic diagnosis of AS.
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11
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Bałdyga N, Sarosiak A, Oziębło D, Furmanek M, Szulborski K, Szaflik JP, Skarżyński H, Ołdak M. Complex Phenotypic Presentation of Syndromic Hearing Loss Deciphered as Three Separate Clinical Entities: How Genetic Testing Guides Final Diagnosis. Audiol Neurootol 2020; 26:226-235. [PMID: 33352548 DOI: 10.1159/000510695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 08/05/2020] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Genetically determined prelingual hearing loss (HL) may occur in an isolated or syndromic form. OBJECTIVE The aim of the study was to unravel the genetic cause of medical problems in a 21-year-old woman, whose phenotypic presentation extended beyond Stickler syndrome and included enlarged vestibular aqueduct (EVA) and persistent microhematuria. METHODS AND RESULTS After sequencing of clinical exome, a known de novo COL2A1 pathogenic variant (c.1833+1G>A, p.?) causative for Stickler syndrome and one paternally inherited pathogenic change in COL4A5 (c.1871G>A, p.Gly624Asp) causative for X-linked Alport syndrome were found. No pathogenic variants, including those within the SLC26A4 5' region (Caucasian EVA haplotype), explaining the development of EVA, were identified. CONCLUSIONS The study reveals a multilocus genomic variation in one individual and provides a molecular diagnosis of two HL syndromes that co-occur in the proband independent of each other. For the third entity, EVA, no etiological factor was identified. Our data emphasize the relevance of detailed clinical phenotyping for accurate genotype interpretation. Focus on broadening the phenotypic spectrum of known genetic syndromes may actually obscure patients with multiple molecular diagnoses.
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Affiliation(s)
- Natalia Bałdyga
- Department of Genetics, Institute of Physiology and Pathology of Hearing, Warsaw, Poland
| | - Anna Sarosiak
- Department of Genetics, Institute of Physiology and Pathology of Hearing, Warsaw, Poland.,Postgraduate School of Molecular Medicine, Medical University of Warsaw, Warsaw, Poland
| | - Dominika Oziębło
- Department of Genetics, Institute of Physiology and Pathology of Hearing, Warsaw, Poland.,Postgraduate School of Molecular Medicine, Medical University of Warsaw, Warsaw, Poland
| | - Mariusz Furmanek
- Bioimaging Research Center, Institute of Physiology and Pathology of Hearing, Warsaw, Poland
| | - Kamil Szulborski
- Department of Ophthalmology, Medical University of Warsaw, Warsaw, Poland
| | - Jacek P Szaflik
- Department of Ophthalmology, Medical University of Warsaw, Warsaw, Poland
| | - Henryk Skarżyński
- Oto-Rhino-Laryngology Surgery Clinic, Institute of Physiology and Pathology of Hearing, Warsaw, Poland
| | - Monika Ołdak
- Department of Genetics, Institute of Physiology and Pathology of Hearing, Warsaw, Poland,
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12
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Żurowska AM, Bielska O, Daca-Roszak P, Jankowski M, Szczepańska M, Roszkowska-Bjanid D, Kuźma-Mroczkowska E, Pańczyk-Tomaszewska M, Moczulska A, Drożdż D, Hadjipanagi D, Deltas C, Ostalska-Nowicka D, Rabiega A, Taraszkiewicz J, Taranta-Janusz K, Wieczorkiewicz-Plaza A, Jobs K, Mews J, Musiał K, Jakubowska A, Nosek H, Jander AE, Koutsofti C, Stanisławska-Sachadyn A, Kuleszo D, Ziętkiewicz E, Lipska-Ziętkiewicz BS. Mild X-linked Alport syndrome due to the COL4A5 G624D variant originating in the Middle Ages is predominant in Central/East Europe and causes kidney failure in midlife. Kidney Int 2020; 99:1451-1458. [PMID: 33309955 DOI: 10.1016/j.kint.2020.10.040] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 10/23/2020] [Accepted: 10/30/2020] [Indexed: 12/14/2022]
Abstract
A study of 269 children enrolled into a National Registry for children with persistent glomerular hematuria identified 131 individuals with genetically confirmed X-linked Alport Syndrome. A single variant c.1871G>A p.Gly624Asp (G624D) in COL4A5 was predominant and accounted for 39% of X-linked Alport Syndrome in unrelated Polish families (44 of 113). To evaluate its origins, the genetic variation in a 2.79 Mb segment encompassing the COL4A5 locus on chromosome X was assessed. All G624D alleles were found on the same rare haplotype background, indicating a founder effect dating back to the 12-13th century. The phenotypic data of 131 children with X-linked Alport Syndrome and their 195 affected adult relatives revealed that the G624D variant was associated with a significantly milder clinical course in comparison to other pathogenic COL4A5 variants. Furthermore the clinical course of this genetically uniform cohort was milder than that observed in individuals with other COL4A5 missense mutations. In spite of the benign clinical manifestation throughout childhood and early adulthood, the G624D variant confers significant risk for both kidney failure and deafness in males, albeit 20-30 years later than that observed in individuals with other COL4A5 pathogenic variants (50% cumulative risk of starting dialysis at 54 years (95% confidence interval: 50-62) v. 26 years (95% confidence interval: 22-30)). Thus, males with G624D are candidates for existing and emerging therapies for Alport Syndrome.
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Affiliation(s)
- Aleksandra M Żurowska
- Rare Diseases Centre, Medical University of Gdańsk, Gdańsk, Poland; Department of Pediatrics, Nephrology and Hypertension, Faculty of Medicine, Medical University of Gdańsk, Gdańsk, Poland.
| | - Olga Bielska
- Department of Pediatrics, Nephrology and Hypertension, Faculty of Medicine, Medical University of Gdańsk, Gdańsk, Poland
| | | | - Maciej Jankowski
- Department of Biology and Medical Genetics, Faculty of Medicine, Medical University of Gdańsk, Gdańsk, Poland
| | - Maria Szczepańska
- Department of Pediatrics, Faculty of Medical Sciences in Zabrze, Medical University of Silesia in Katowice, Zabrze, Poland
| | - Dagmara Roszkowska-Bjanid
- Pediatric Nephrology Ward With Dialysis Division for Children, Public Clinical Hospital, Zabrze, Poland
| | | | | | - Anna Moczulska
- Department of Pediatric Nephrology and Hypertension, Jagiellonian University Medical College, Cracow, Poland
| | - Dorota Drożdż
- Department of Pediatric Nephrology and Hypertension, Jagiellonian University Medical College, Cracow, Poland
| | - Despina Hadjipanagi
- Center of Excellence in Biobanking and Biomedical Research, Molecular Medicine Research Center, University of Cyprus Medical School, Nicosia, Cyprus
| | - Constantinos Deltas
- Center of Excellence in Biobanking and Biomedical Research, Molecular Medicine Research Center, University of Cyprus Medical School, Nicosia, Cyprus
| | - Danuta Ostalska-Nowicka
- Department of Pediatric Cardiology and Hypertensiology, Poznan University of Medical Sciences, Poznań, Poland
| | - Alina Rabiega
- Department of Pediatric Cardiology and Hypertensiology, Poznan University of Medical Sciences, Poznań, Poland
| | - Janina Taraszkiewicz
- Department of Pediatric Nephrology, Team of Municipal Hospitals in Chorzów, Chorzów, Poland
| | | | | | - Katarzyna Jobs
- Department of Pediatrics, Pediatric Nephrology and Allergology, Military Institute of Medicine, Warsaw, Poland
| | - Judyta Mews
- Department of Pediatrics, Pediatric Nephrology and Allergology, Military Institute of Medicine, Warsaw, Poland
| | - Kinga Musiał
- Department of Pediatric Nephrology, Wrocław Medical University, Wrocław, Poland
| | - Anna Jakubowska
- Department of Pediatric Nephrology, Wrocław Medical University, Wrocław, Poland
| | - Hanna Nosek
- Department of Pediatrics, Gastroenterology and Nutrition, University of Warmia and Mazury, Olsztyn, Poland
| | - Anna E Jander
- Department of Pediatrics, Immunology and Nephrology, Polish Mothers Memorial Hospital Research Institute, Łódź, Poland
| | - Constantina Koutsofti
- Center of Excellence in Biobanking and Biomedical Research, Molecular Medicine Research Center, University of Cyprus Medical School, Nicosia, Cyprus
| | | | - Dominka Kuleszo
- Department of Biology and Medical Genetics, Faculty of Medicine, Medical University of Gdańsk, Gdańsk, Poland
| | - Ewa Ziętkiewicz
- Institute of Human Genetics, Polish Academy of Sciences, Poznań, Poland
| | - Beata S Lipska-Ziętkiewicz
- Rare Diseases Centre, Medical University of Gdańsk, Gdańsk, Poland; Clinical Genetics Unit, Department of Biology and Medical Genetics, Faculty of Medicine, Medical University of Gdańsk, Gdańsk, Poland.
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13
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Mutations in Collagen Genes in the Context of an Isolated Population. Genes (Basel) 2020; 11:genes11111377. [PMID: 33233744 PMCID: PMC7699876 DOI: 10.3390/genes11111377] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 11/19/2020] [Accepted: 11/19/2020] [Indexed: 01/16/2023] Open
Abstract
Genetic studies of population isolates have great potential to provide a unique insight into genetic differentiation and phenotypic expressions. Galičnik village is a population isolate located in the northwest region of the Republic of North Macedonia, established around the 10th century. Alport syndrome-linked nephropathy with a complex inheritance pattern has been described historically among individuals in the village. In order to determine the genetic basis of the nephropathies and to characterize the genetic structure of the population, 23 samples were genotyped using a custom-made next generation sequencing panel and 111 samples using population genetic markers. We compared the newly obtained population data with fifteen European population data sets. NGS analysis revealed four different mutations in three different collagen genes in twelve individuals within the Galičnik population. The genetic isolation and small effective population size of Galičnik village have resulted in a high level of genomic homogeneity, with domination of R1a-M458 and R1b-U106* haplogroups. The study explains complex autosomal in cis digenic and X-linked inheritance patterns of nephropathy in the isolated population of Galičnik and describes the first case of Alport syndrome family with three different collagen gene mutations.
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14
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Park E, Lee C, Kim NKD, Ahn YH, Park YS, Lee JH, Kim SH, Cho MH, Cho H, Yoo KH, Shin JI, Kang HG, Ha IS, Park WY, Cheong HI. Genetic Study in Korean Pediatric Patients with Steroid-Resistant Nephrotic Syndrome or Focal Segmental Glomerulosclerosis. J Clin Med 2020; 9:jcm9062013. [PMID: 32604935 PMCID: PMC7355646 DOI: 10.3390/jcm9062013] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 06/16/2020] [Accepted: 06/19/2020] [Indexed: 11/17/2022] Open
Abstract
Steroid-resistant nephrotic syndrome (SRNS) is one of the major causes of end-stage renal disease (ESRD) in childhood and is mostly associated with focal segmental glomerulosclerosis (FSGS). More than 50 monogenic causes of SRNS or FSGS have been identified. Recently, the mutation detection rate in pediatric patients with SRNS has been reported to be approximately 30%. In this study, genotype-phenotype correlations in a cohort of 291 Korean pediatric patients with SRNS/FSGS were analyzed. The overall mutation detection rate was 43.6% (127 of 291 patients). WT1 was the most common causative gene (23.6%), followed by COQ6 (8.7%), NPHS1 (8.7%), NUP107 (7.1%), and COQ8B (6.3%). Mutations in COQ6, NUP107, and COQ8B were more frequently detected, and mutations in NPHS2 were less commonly detected in this cohort than in study cohorts from Western countries. The mutation detection rate was higher in patients with congenital onset, those who presented with proteinuria or chronic kidney disease/ESRD, and those who did not receive steroid treatment. Genetic diagnosis in patients with SRNS provides not only definitive diagnosis but also valuable information for decisions on treatment policy and prediction of prognosis. Therefore, further genotype-phenotype correlation studies are required.
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Affiliation(s)
- Eujin Park
- Department of Pediatrics, Seoul National University College of Medicine, Seoul 03080, Korea; (E.P.); (Y.H.A.); (H.G.K.); (I.-S.H.)
- Department of Pediatrics, Kangnam Sacred Heart Hospital, Hallym University College of Medicine, Seoul 07441, Korea
| | - Chung Lee
- Samsung Genome Institute, Samsung Medical Center, Seoul 06351, Korea; (C.L.); (N.K.D.K.); (W.-Y.P.)
- GENINUS Inc., Seoul 05836, Korea
| | - Nayoung K. D. Kim
- Samsung Genome Institute, Samsung Medical Center, Seoul 06351, Korea; (C.L.); (N.K.D.K.); (W.-Y.P.)
- GENINUS Inc., Seoul 05836, Korea
| | - Yo Han Ahn
- Department of Pediatrics, Seoul National University College of Medicine, Seoul 03080, Korea; (E.P.); (Y.H.A.); (H.G.K.); (I.-S.H.)
| | - Young Seo Park
- Department of Pediatrics, Asan Medical Center Children’s Hospital, University of Ulsan College of Medicine, Seoul 05505, Korea; (Y.S.P.); (J.H.L.)
| | - Joo Hoon Lee
- Department of Pediatrics, Asan Medical Center Children’s Hospital, University of Ulsan College of Medicine, Seoul 05505, Korea; (Y.S.P.); (J.H.L.)
| | - Seong Heon Kim
- Department of Pediatrics, Pusan National University Children’s Hospital, Yangsan 50612, Korea;
| | - Min Hyun Cho
- Department of Pediatrics, Kyungpook National University School of Medicine, Daegu 41944, Korea;
| | - Heeyeon Cho
- Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Korea;
| | - Kee Hwan Yoo
- Department of Pediatrics, Korea University Guro Hospital, Seoul 02841, Korea;
| | - Jae Il Shin
- Department of Pediatrics, Yonsei University College of Medicine, Seoul 03722, Korea;
- Division of Pediatric Nephrology, Severance Children’s Hospital, Seoul 03722, Korea
| | - Hee Gyung Kang
- Department of Pediatrics, Seoul National University College of Medicine, Seoul 03080, Korea; (E.P.); (Y.H.A.); (H.G.K.); (I.-S.H.)
| | - Il-Soo Ha
- Department of Pediatrics, Seoul National University College of Medicine, Seoul 03080, Korea; (E.P.); (Y.H.A.); (H.G.K.); (I.-S.H.)
| | - Woong-Yang Park
- Samsung Genome Institute, Samsung Medical Center, Seoul 06351, Korea; (C.L.); (N.K.D.K.); (W.-Y.P.)
- GENINUS Inc., Seoul 05836, Korea
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon 16419, Korea
| | - Hae Il Cheong
- Department of Pediatrics, Seoul National University College of Medicine, Seoul 03080, Korea; (E.P.); (Y.H.A.); (H.G.K.); (I.-S.H.)
- Correspondence: ; Tel.: +82-2-2072-2810
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15
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Zhao X, Shang X, Chen C, Liu L, Wang C, Zhao G, Zhang J, Kong X. Identification of four novel mutations in the COL4A5 gene identified in Chinese patients with X-linked Alport syndrome. Biomed Rep 2020; 13:4. [PMID: 32607233 PMCID: PMC7323451 DOI: 10.3892/br.2020.1311] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 03/30/2020] [Indexed: 11/05/2022] Open
Abstract
Alport syndrome (AS) is an inherited progressive nephropathy caused by mutations in one or two of the type IV collagen novel chains (α3, α4 and α5), which are encoded by COL4A3, COL4A4 and COL4A5, respectively. To date, three genetic forms of AS have been reported, including X-linked AS, autosomal recessive AS, and autosomal dominant AS, and ~80% of patients have X-linked AS caused by mutations in COL4A5. In the present study, four novel and one previously reported COL4A5 mutations were identified using targeted next-generation sequencing in Chinese patients suspected of having AS. The results were confirmed by Sanger sequencing, which revealed two novel missense mutations resulting in the substitution of various glycine residues in a collagenous domain containing Gly-X-Y triplet sequence repeats [c.4198G>C, p.(Gly1400Arg) and c.3428G>T, p.(Gly1143Val)], a previously reported missense mutation [c.3071G>A, p.(Gly1024Glu)], a splice site mutation (c.2146+2T>A) and one frameshift mutation [c.1810delC (p.Thr605Ilefs*13)]. After analyzing the affected family members, it was shown that the identified mutations were associated with severe clinical phenotypes. These results broaden the known spectrum of mutations of the COL4A5 gene associated with AS and may have implications for genetic diagnosis, therapy and genetic counseling of affected families.
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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, Zhengzhou, Henan 450052, P.R. China
| | - Xueliang Shang
- School of Psychology, North China University of Science and Technology, Tang'shan, Hebei 063210, P.R. 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, Zhengzhou, Henan 450052, P.R. 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, Zhengzhou, Henan 450052, P.R. 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, Zhengzhou, Henan 450052, P.R. 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, Zhengzhou, Henan 450052, P.R. China
| | - Junjun Zhang
- Research Institute of Nephrology, Zhengzhou University, Zhengzhou, Henan 450052, P.R. 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, Zhengzhou, Henan 450052, P.R. China
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16
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Lenarduzzi S, Morgan A, Faletra F, Cappellani S, Morgutti M, Mezzavilla M, Peruzzi A, Ghiselli S, Ambrosetti U, Graziano C, Seri M, Gasparini P, Girotto G. Next generation sequencing study in a cohort of Italian patients with syndromic hearing loss. Hear Res 2019; 381:107769. [PMID: 31387071 DOI: 10.1016/j.heares.2019.07.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 07/01/2019] [Accepted: 07/12/2019] [Indexed: 11/19/2022]
Abstract
Hearing loss (HL), one of the most common congenital disorder, affects about one child in 1000. Among the genetic forms of HL, ∼30% of the cases are associated with other signs or symptoms, leading to Syndromic Hearing Loss (SHL) with about 700 different forms described so far. In this report, we refer the clinical and molecular data of 38 Italian SHL unrelated patients, and their relatives, affected by the most common syndromes associated with HL (i.e., Usher, Pendred, Charge, Waardenburg, Alport, Stickler, Branchiootorenal and Microdeletions syndromes). Patients have been analysed using next-generation sequencing (NGS) and High Density (HD)-SNP array technologies. Data analysis led to the identification of nine novel and 27 known causative mutations in 12 genes and two microdeletions in chromosomes 1 and 10, respectively. In particular, as regards to Usher syndrome, that affects 32% of our patients, we were able to reach a molecular diagnosis in 83% of the cases and to identify in Northern Eastern Italy a very common USH2A gene mutation (39%) (c.11864G > A, p.(Trp3955*) which can be defined "Central-Eastern European allele." As regards to Alport syndrome, we were able to potentially reclassify a pathogenic allele in the COL4A3 gene, previously associated only with benign familial hematuria. In all the other cases, the genomic analysis allowed us to confirm the role of known causative genes and to identify several novel and known alleles. Overall, our results highlight the effectiveness of combining an accurate clinical characterization with the use of genomic technologies (NGS and SNP arrays) for the molecular diagnosis of SHL, with a clear positive impact in the management and treatment of all the patients.
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Affiliation(s)
- Stefania Lenarduzzi
- Institute for Maternal and Child Health - IRCCS "Burlo Garofolo", Trieste, Italy.
| | - Anna Morgan
- University of Trieste, Department of Medicine, Surgery and Health Sciences, Trieste, Italy
| | - Flavio Faletra
- Institute for Maternal and Child Health - IRCCS "Burlo Garofolo", Trieste, Italy
| | - Stefania Cappellani
- Institute for Maternal and Child Health - IRCCS "Burlo Garofolo", Trieste, Italy
| | - Marcello Morgutti
- Institute for Maternal and Child Health - IRCCS "Burlo Garofolo", Trieste, Italy
| | - Massimo Mezzavilla
- Institute for Maternal and Child Health - IRCCS "Burlo Garofolo", Trieste, Italy
| | - Adelaide Peruzzi
- University of Trieste, Department of Medicine, Surgery and Health Sciences, Trieste, Italy
| | - Sara Ghiselli
- Institute for Maternal and Child Health - IRCCS "Burlo Garofolo", Trieste, Italy
| | - Umberto Ambrosetti
- Department of Clinical Sciences and Community Health, Università degli Studi di Milano, Italy; U.O.S.D. of Audiology, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico di Milano, Italy
| | - Claudio Graziano
- Unit of Medical Genetics, S. Orsola-Malpighi Hospital, Bologna, Italy
| | - Marco Seri
- Unit of Medical Genetics, S. Orsola-Malpighi Hospital, Bologna, Italy
| | - Paolo Gasparini
- Institute for Maternal and Child Health - IRCCS "Burlo Garofolo", Trieste, Italy; University of Trieste, Department of Medicine, Surgery and Health Sciences, Trieste, Italy
| | - Giorgia Girotto
- Institute for Maternal and Child Health - IRCCS "Burlo Garofolo", Trieste, Italy; University of Trieste, Department of Medicine, Surgery and Health Sciences, Trieste, Italy
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17
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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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18
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Savige J, Ariani F, Mari F, Bruttini M, Renieri A, Gross O, Deltas C, Flinter F, Ding J, Gale DP, Nagel M, Yau M, Shagam L, Torra R, Ars E, Hoefele J, Garosi G, Storey H. Expert consensus guidelines for the genetic diagnosis of Alport syndrome. Pediatr Nephrol 2019; 34:1175-1189. [PMID: 29987460 DOI: 10.1007/s00467-018-3985-4] [Citation(s) in RCA: 76] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 02/22/2018] [Accepted: 05/10/2018] [Indexed: 12/16/2022]
Abstract
Recent expert guidelines recommend genetic testing for the diagnosis of Alport syndrome. Here, we describe current best practice and likely future developments. In individuals with suspected Alport syndrome, all three COL4A5, COL4A3 and COL4A4 genes should be examined for pathogenic variants, probably by high throughput-targeted next generation sequencing (NGS) technologies, with a customised panel for simultaneous testing of the three Alport genes. These techniques identify up to 95% of pathogenic COL4A variants. Where causative pathogenic variants cannot be demonstrated, the DNA should be examined for deletions or insertions by re-examining the NGS sequencing data or with multiplex ligation-dependent probe amplification (MLPA). These techniques identify a further 5% of variants, and the remaining few changes include deep intronic splicing variants or cases of somatic mosaicism. Where no pathogenic variants are found, the basis for the clinical diagnosis should be reviewed. Genes in which mutations produce similar clinical features to Alport syndrome (resulting in focal and segmental glomerulosclerosis, complement pathway disorders, MYH9-related disorders, etc.) should be examined. NGS approaches have identified novel combinations of pathogenic variants in Alport syndrome. Two variants, with one in COL4A3 and another in COL4A4, produce a more severe phenotype than an uncomplicated heterozygous change. NGS may also identify further coincidental pathogenic variants in genes for podocyte-expressed proteins that also modify the phenotype. Our understanding of the genetics of Alport syndrome is evolving rapidly, and both genetic and non-genetic factors are likely to contribute to the observed phenotypic variability.
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Affiliation(s)
- Judy Savige
- Department of Medicine, Melbourne and Northern Health, The University of Melbourne, Parkville, VIC, 3050, Australia.
| | | | | | | | | | - Oliver Gross
- Clinic of Nephrology and Rheumatology, University of Gottingen, Gottingen, Germany
| | | | - Frances Flinter
- Department of Clinical Genetics, Guys' and St Thomas' NHS Foundation Trust, London, UK
| | - Jie Ding
- Peking University First Hospital, Beijing, China
| | - Daniel P Gale
- Centre for Nephrology, Royal Free Hospital, University College London, London, UK
| | - Mato Nagel
- Centre for Nephrology and Metabolic Disorders, Weisswasser, Germany
| | - Michael Yau
- Genetics, Guy's Hospital, Viapath, London, UK
| | - Lev Shagam
- Institute of Pediatrics, Pirogov Russian Medical University, Moscow, Russia
| | - Roser Torra
- Inherited Kidney Disorders, Nephrology Department, Fundacio Puigvert, Instituto de Investigacion Carlos III, Universitat Autonoma de Barcelona, Barcelona, Spain
| | - Elisabet Ars
- Molecular Biology Laboratory, Fundacio Puigvert, Instituto de Investigacion Carlos III, Universitat Autonoma de Barcelona, Barcelona, Spain
| | - Julia Hoefele
- Institute of Human Genetics, Technical University Munich, Munich, Germany
| | - Guido Garosi
- Nephrology, Dialysis and Transplantation, Azienda Ospedaliera Universitaria Senese, Siena, Italy
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19
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Xia L, Cao Y, Guo Y, Ba G, Luo Q, Shi H, Feng Y, Yin S. A Novel Heterozygous Mutation of the COL4A3 Gene Causes a Peculiar Phenotype without Hematuria and Renal Function Impairment in a Chinese Family. DISEASE MARKERS 2019; 2019:8705989. [PMID: 30881523 PMCID: PMC6387717 DOI: 10.1155/2019/8705989] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 01/16/2019] [Accepted: 01/17/2019] [Indexed: 01/15/2023]
Abstract
Mutations in the COL4A3 gene are frequently reported to be associated with various types of hereditary nephropathy. COL4A3 encodes the α3 chain of type IV collagen, which is the main structural protein in the basement membrane. Mutations in this gene are always related to kidney performance, and deafness and ocular lesion have also been reported. In this study, using next-generation sequencing, we investigated the DNA of a family visiting a clinic for hearing loss. A new missense mutation was found in COL4A3 of 5 patients, c.3227C>T (p.P1076L). Based on these results, we predict that the mutation is pathogenic and leads to abnormal collagen IV. Here, we report for the first time on this autosomal dominant syndrome, characterized by hearing loss and eye abnormalities, but without renal damage, in all carriers. Since the oldest patient in the trial was less than 50 years old, however, we recommend that renal examination be reviewed regularly. Our results reveal expansion in the mutation spectrum of the COL4A3 gene and phenotypic spectrum of collagen IV disease. Our study suggests that next-generation sequencing is an economical and effective method and may help in the accurate diagnosis and treatment of these patients.
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Affiliation(s)
- Liang Xia
- Department of Otolaryngology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, No. 600, Yishan Road, Xuhui District, 200233 Shanghai, China
| | - Yangjia Cao
- Metabolic Bone Disease and Genetic Research Unit, Department of Osteoporosis and Bone Diseases, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yi-Shan Rd, Shanghai 200233, China
| | - Yang Guo
- Department of Otolaryngology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, No. 600, Yishan Road, Xuhui District, 200233 Shanghai, China
| | - Guangyi Ba
- Department of Otolaryngology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, No. 600, Yishan Road, Xuhui District, 200233 Shanghai, China
| | - Qiong Luo
- Department of Otolaryngology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, No. 600, Yishan Road, Xuhui District, 200233 Shanghai, China
| | - Haibo Shi
- Department of Otolaryngology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, No. 600, Yishan Road, Xuhui District, 200233 Shanghai, China
| | - Yanmei Feng
- Department of Otolaryngology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, No. 600, Yishan Road, Xuhui District, 200233 Shanghai, China
| | - Shankai Yin
- Department of Otolaryngology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, No. 600, Yishan Road, Xuhui District, 200233 Shanghai, China
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20
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Macheroux EP, Braunisch MC, Pucci Pegler S, Satanovskij R, Riedhammer KM, Günthner R, Gross O, Nagel M, Renders L, Hoefele J. The Hypomorphic Variant p.(Gly624Asp) in COL4A5 as a Possible Cause for an Unexpected Severe Phenotype in a Family With X-Linked Alport Syndrome. Front Pediatr 2019; 7:485. [PMID: 31850286 PMCID: PMC6887795 DOI: 10.3389/fped.2019.00485] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 11/05/2019] [Indexed: 01/16/2023] Open
Abstract
Background: Alport syndrome (AS) is a progressive kidney disorder leading to end stage renal disease (ESRD). Extrarenal symptoms like hearing loss and ocular changes can be observed. Approximately 85% of the patients carry pathogenic variants in COL4A5 (X-linked inheritance). The variant c.1871G>A, p.(Gly624Asp) in COL4A5 is described in the literature as a hypomorphic variant associated with thin basement membrane nephropathy (TBMN). ESRD was only seen rarely at a median age of 50 years and extrarenal manifestations have only been described in single cases. Case report and Methods: This is a report on a family with X-linked AS. In the female index patient, microscopic hematuria, and proteinuria were observed beginning at the age of 20 years and 41 years, respectively. Microscopic hematuria was also present in the daughter (from 6th month of life), the son (from 22nd month of life), the mother and the maternal grandniece. Proteinuria was observed in the maternal aunt and paternal grandmother. The father of the index patient, a paternal uncle and a second cousin presented with ESRD at the age of 49, 34, and 70 years of life, respectively. Extrarenal manifestations were absent in the whole family. In the index patient, her children and her mother molecular diagnostics were performed using Sanger and exome sequencing. Results: In all examined family members the variant c.1871G>A, p.(Gly624Asp) in COL4A5 was identified. With the exception of the index patient, who was homozygous for this variant, all family members carried the variant heterozygously, or hemizygously. A different or additional monogenic hereditary nephropathy could not be detected by exome sequencing of the index patient. Discussion: This is the first report of a patient with the variant p.(Gly624Asp) in COL4A5 in a homozygous state. The variant was previously reported as a mild variant requiring dialysis in less than 10%. The family presented, however, with a more severe clinical course. We therefore suggest to question the term "hypomorphic" in the context of the variant p.(Gly624Asp) although molecular diagnostics could not be done in all affected family members.
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Affiliation(s)
- Eva Pauline Macheroux
- Institute of Human Genetics, School of Medicine, Technical University of Munich, Munich, Germany
| | - Matthias C Braunisch
- Institute of Human Genetics, School of Medicine, Technical University of Munich, Munich, Germany.,Department of Nephrology, School of Medicine, Technical University of Munich, Munich, Germany
| | - Stephanie Pucci Pegler
- Institute of Human Genetics, School of Medicine, Technical University of Munich, Munich, Germany
| | - Robin Satanovskij
- Institute of Human Genetics, School of Medicine, Technical University of Munich, Munich, Germany.,Department of Nephrology, School of Medicine, Technical University of Munich, Munich, Germany
| | - Korbinian M Riedhammer
- Institute of Human Genetics, School of Medicine, Technical University of Munich, Munich, Germany.,Department of Nephrology, School of Medicine, Technical University of Munich, Munich, Germany
| | - Roman Günthner
- Institute of Human Genetics, School of Medicine, Technical University of Munich, Munich, Germany.,Department of Nephrology, School of Medicine, Technical University of Munich, Munich, Germany
| | - Oliver Gross
- Clinic of Nephrology and Rheumatology, University Medical Center Goettingen, University of Goettingen, Goettingen, Germany
| | - Mato Nagel
- Center for Nephrology and Metabolic Medicine, Weisswasser, Germany
| | - Lutz Renders
- Department of Nephrology, School of Medicine, Technical University of Munich, Munich, Germany
| | - Julia Hoefele
- Institute of Human Genetics, School of Medicine, Technical University of Munich, Munich, Germany
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21
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Li A, Cui YX, Lv X, Liu JH, Gao EZ, Wei XX, Xia XY, Gao CL, Liu FX, Xia ZK, Liu ZH, Li XJ. The COL4A3 and COL4A4 Digenic Mutations in cis Result in Benign Familial Hematuria in a Large Chinese Family. Cytogenet Genome Res 2018; 154:132-136. [PMID: 29742505 DOI: 10.1159/000488163] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Indexed: 01/20/2023] Open
Abstract
Mutations in the COL4A5 gene result in X-linked Alport syndrome, homozygous or compound heterozygous mutations in COL4A3 or COL4A4 are responsible for autosomal recessive Alport syndrome, and heterozygous mutations in COL4A3 or COL4A4 cause autosomal dominant Alport syndrome or benign familial hematuria. Recently, the existence of a digenic inheritance in Alport syndrome has been demonstrated. We here report heterozygous COL4A3 and COL4A4 digenic mutations in cis responsible for benign familial hematuria. Using bioinformatics analyses and pedigree verification, we showed that COL4A4 c.1471C>T and COL4A3 c.3418 + 1G>T variants in cis are pathogenic and co-segregate with the benign familial hematuria. This result suggests that COL4A3 and COL4A4 digenic mutations in cis mimicking an autosomal dominant inheritance should be considered as a novel inheritance pattern of benign familial hematuria, although the disease-causing mechanism remains unknown.
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22
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Mutation analysis of COL4A3 and COL4A4 genes in a Chinese autosomal-dominant Alport syndrome family. J Genet 2018; 96:389-392. [PMID: 28674241 DOI: 10.1007/s12041-017-0786-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Autosomal dominant Alport syndrome (ADAS) accounts for 5% of all cases of Alport syndrome (AS), a primary basement membrane disorder arising from mutations in genes encoding the type IV collagen protein family.Mutations in COL4A3 and COL4A4 genes were reported to be associated with ADAS. In this study, clinical data in a large consanguineous family with seven affected members were reviewed, and genomic DNA was extracted. For mutation screening, all exons of COL4A3 and COL4A4 genes were polymerase chain reaction-amplified and direct sequenced from genomic DNA, and the mutations were analyzed by comparing with members in this family, 100 ethnicitymatched controls and the sequence of COL4A3 and COL4A4 genes from GenBank. A novel mutation determining a nucleotide change was found, i.e. c.4195 A>T (p.Met1399Leu) at 44th exon of COL4A4 gene, and this mutation showed heterozygous in all patients of this family. Also a novel intron mutation (c.4127+11 C>T) was observed at COL4A4 gene. Thus the novel missense mutation c.4195 A>T (p.Met1399Leu) and the intron mutation (c.4127+11 C>T) at COL4A4 gene might be responsible for ADAS of this family. Our results broadened the spectrum of mutations in COL4A4 and had important implications in the diagnosis, prognosis, and genetic counselling of ADAS.
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23
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Cervera-Acedo C, Coloma A, Huarte-Loza E, Sierra-Carpio M, Domínguez-Garrido E. Phenotype variability in a large Spanish family with Alport syndrome associated with novel mutations in COL4A3 gene. BMC Nephrol 2017; 18:325. [PMID: 29089023 PMCID: PMC5664579 DOI: 10.1186/s12882-017-0735-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 09/25/2017] [Indexed: 11/30/2022] Open
Abstract
Background Alport syndrome is an inherited renal disorder characterized by glomerular basement membrane lesions with hematuria, proteinuria and frequent hearing defects and ocular abnormalities. The disease is associated with mutations in genes encoding α3, α4, or α5 chains of type IV collagen, namely COL4A3 and COL4A4 in chromosome 2 and COL4A5 in chromosome X. In contrast to the well-known X-linked and autosomal recessive phenotypes, there is very little information about the autosomal dominant. In view of the wide spectrum of phenotypes, an exact diagnosis is sometimes difficult to achieve. Methods We investigated a Spanish family with variable phenotype of autosomal dominant Alport syndrome using clinical, histological, and genetic analysis. Results Mutational analysis of COL4A3 and COL4A4 genes showed a novel heterozygous mutation (c. 998G > A; p.G333E) in exon 18 of the COL4A3 gene. Among relatives carrying the novel mutation, the clinical phenotype was variable. Two additional COL4A3 mutations were found, a Pro-Leu substitution in exon 48 (p.P1461L) and a Ser-Cys substitution in exon 49 (p.S1492C), non-pathogenics alone. Conclusion Carriers of p.G333E and p.P1461L or p.S1492C mutations in COL4A3 gene appear to be more severely affected than carriers of only p.G333E mutation, and the clinical findings has an earlier onset. In this way, we could speculate on a synergistic effect of compound heterozygosity that could explain the different phenotype observed in this family.
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Affiliation(s)
- C Cervera-Acedo
- Molecular Diagnostics Unit, Center for Biomedical Research (CIBIR), Fundación Rioja Salud, C/Piqueras 98, 26006, Logroño, La Rioja, Spain
| | - A Coloma
- Department of Nephrology, San Pedro Hospital, Logroño, La Rioja, Spain
| | - E Huarte-Loza
- Department of Nephrology, San Pedro Hospital, Logroño, La Rioja, Spain
| | - M Sierra-Carpio
- Department of Nephrology, San Pedro Hospital, Logroño, La Rioja, Spain
| | - E Domínguez-Garrido
- Molecular Diagnostics Unit, Center for Biomedical Research (CIBIR), Fundación Rioja Salud, C/Piqueras 98, 26006, Logroño, La Rioja, Spain.
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24
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Papazachariou L, Papagregoriou G, Hadjipanagi D, Demosthenous P, Voskarides K, Koutsofti C, Stylianou K, Ioannou P, Xydakis D, Tzanakis I, Papadaki A, Kallivretakis N, Nikolakakis N, Perysinaki G, Gale DP, Diamantopoulos A, Goudas P, Goumenos D, Soloukides A, Boletis I, Melexopoulou C, Georgaki E, Frysira E, Komianou F, Grekas D, Paliouras C, Alivanis P, Vergoulas G, Pierides A, Daphnis E, Deltas C. Frequent COL4 mutations in familial microhematuria accompanied by later-onset Alport nephropathy due to focal segmental glomerulosclerosis. Clin Genet 2017. [PMID: 28632965 DOI: 10.1111/cge.13077] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Familial microscopic hematuria (FMH) is associated with a genetically heterogeneous group of conditions including the collagen-IV nephropathies, the heritable C3/CFHR5 nephropathy and the glomerulopathy with fibronectin deposits. The clinical course varies widely, ranging from isolated benign familial hematuria to end-stage renal disease (ESRD) later in life. We investigated 24 families using next generation sequencing (NGS) for 5 genes: COL4A3, COL4A4, COL4A5, CFHR5 and FN1. In 17 families (71%), we found 15 pathogenic mutations in COL4A3/A4/A5, 9 of them novel. In 5 families patients inherited classical AS with hemizygous X-linked COL4A5 mutations. Even more patients developed later-onset Alport-related nephropathy having inherited heterozygous COL4A3/A4 mutations that cause thin basement membranes. Amongst 62 heterozygous or hemizygous patients, 8 (13%) reached ESRD, while 25% of patients with heterozygous COL4A3/A4 mutations, aged >50-years, reached ESRD. In conclusion, COL4A mutations comprise a frequent cause of FMH. Heterozygous COL4A3/A4 mutations predispose to renal function impairment, supporting that thin basement membrane nephropathy is not always benign. The molecular diagnosis is essential for differentiating the X-linked from the autosomal recessive and dominant inheritance. Finally, NGS technology is established as the gold standard for the diagnosis of FMH and associated collagen-IV glomerulopathies, frequently averting the need for invasive renal biopsies.
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Affiliation(s)
- L Papazachariou
- Molecular Medicine Research Center & Laboratory of Molecular and Medical Genetics, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus
| | - G Papagregoriou
- Molecular Medicine Research Center & Laboratory of Molecular and Medical Genetics, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus
| | - D Hadjipanagi
- Molecular Medicine Research Center & Laboratory of Molecular and Medical Genetics, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus
| | - P Demosthenous
- Molecular Medicine Research Center & Laboratory of Molecular and Medical Genetics, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus
| | - K Voskarides
- Molecular Medicine Research Center & Laboratory of Molecular and Medical Genetics, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus
| | - C Koutsofti
- Molecular Medicine Research Center & Laboratory of Molecular and Medical Genetics, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus
| | - K Stylianou
- Department of Nephrology, University of Crete-Greece, Heraklion, Greece
| | - P Ioannou
- Department of Nephrology, University of Crete-Greece, Heraklion, Greece
| | - D Xydakis
- Department of Nephrology, University of Crete-Greece, Heraklion, Greece
| | - I Tzanakis
- Department of Nephrology, General Hospital of Chania, Crete, Greece
| | - A Papadaki
- Department of Nephrology, General Hospital of Chania, Crete, Greece
| | - N Kallivretakis
- Department of Nephrology, General Hospital of Chania, Crete, Greece
| | - N Nikolakakis
- Division of Nephrology, General Hospital of Rethymno, Crete, Greece
| | - G Perysinaki
- Division of Nephrology, General Hospital of Rethymno, Crete, Greece
| | - D P Gale
- UCL Division of Medicine and Centre for Nephrology, University College London, London, UK
| | | | - P Goudas
- IATOS Dialysis Unit, Patra, Greece
| | - D Goumenos
- Department of Nephrology, Medical School, University of Patras, Patra, Greece
| | - A Soloukides
- Protypo Nefrologiko Athinon Dialysis Center, Athens, Greece
| | - I Boletis
- Department of Nephrology, Laikon Hospital, Athens, Greece
| | - C Melexopoulou
- Department of Nephrology, Laikon Hospital, Athens, Greece
| | - E Georgaki
- Pediatric Nephrology Unit, "IASO" Children's Hospital, Athens, Greece
| | - E Frysira
- Department of Pediatrics, Athens University Medical School, Agia Sophia Children's Hospital, Athens, Greece
| | - F Komianou
- Department of Medical Genetics, Athens University Medical School, Agia Sophia Children's Hospital, Athens, Greece
| | - D Grekas
- University Hospital AXEPA, Thessaloniki, Greece
| | - C Paliouras
- Department of Nephrology, General Hospital of Rhodes, Rhodes, Greece
| | - P Alivanis
- Department of Nephrology, General Hospital of Rhodes, Rhodes, Greece
| | - G Vergoulas
- Organ Transplant Unit, Hippokratio General Hospital, Thessaloniki, Greece
| | - A Pierides
- Molecular Medicine Research Center & Laboratory of Molecular and Medical Genetics, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus.,Department of Nephrology, Hippocrateon Hospital, Nicosia, Cyprus
| | - E Daphnis
- Department of Nephrology, University of Crete-Greece, Heraklion, Greece
| | - C Deltas
- Molecular Medicine Research Center & Laboratory of Molecular and Medical Genetics, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus
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25
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A functional variant in NEPH3 gene confers high risk of renal failure in primary hematuric glomerulopathies. Evidence for predisposition to microalbuminuria in the general population. PLoS One 2017; 12:e0174274. [PMID: 28334007 PMCID: PMC5363870 DOI: 10.1371/journal.pone.0174274] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2016] [Accepted: 03/06/2017] [Indexed: 01/06/2023] Open
Abstract
Background Recent data emphasize that thin basement membrane nephropathy (TBMN) should not be viewed as a form of benign familial hematuria since chronic renal failure (CRF) and even end-stage renal disease (ESRD), is a possible development for a subset of patients on long-term follow-up, through the onset of focal and segmental glomerulosclerosis (FSGS). We hypothesize that genetic modifiers may explain this variability of symptoms. Methods We looked in silico for potentially deleterious functional SNPs, using very strict criteria, in all the genes significantly expressed in the slit diaphragm (SD). Two variants were genotyped in a cohort of well-studied adult TBMN patients from 19 Greek-Cypriot families, with a homogeneous genetic background. Patients were categorized as “Severe” or “Mild”, based on the presence or not of proteinuria, CRF and ESRD. A larger pooled cohort (HEMATURIA) of 524 patients, including IgA nephropathy patients, was used for verification. Additionally, three large general population cohorts [Framingham Heart Study (FHS), KORAF4 and SAPHIR] were used to investigate if the NEPH3-V353M variant has any renal effect in the general population. Results and conclusions Genotyping for two high-scored variants in 103 TBMN adult patients with founder mutations who were classified as mildly or severely affected, pointed to an association with variant NEPH3-V353M (filtrin). This promising result prompted testing in the larger pooled cohort (HEMATURIA), indicating an association of the 353M variant with disease severity under the dominant model (p = 3.0x10-3, OR = 6.64 adjusting for gender/age; allelic association: p = 4.2x10-3 adjusting for patients’ kinships). Subsequently, genotyping 6,531 subjects of the Framingham Heart Study (FHS) revealed an association of the homozygous 353M/M genotype with microalbuminuria (p = 1.0x10-3). Two further general population cohorts, KORAF4 and SAPHIR confirmed the association, and a meta-analysis of all three cohorts (11,258 individuals) was highly significant (p = 1.3x10-5, OR = 7.46). Functional studies showed that Neph3 homodimerization and Neph3-Nephrin heterodimerization are disturbed by variant 353M. Additionally, 353M was associated with differential activation of the unfolded protein response pathway, when overexpressed in stressed cultured undifferentiated podocyte cells, thus attesting to its functional significance. Genetics and functional studies support a “rare variant-strong effect” role for NEPH3-V353M, by exerting a negative modifier effect on primary glomerular hematuria. Additionally, genetics studies provide evidence for a role in predisposing homozygous subjects of the general population to micro-albuminuria.
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26
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Syndrome d’Alport : néphropathie héréditaire associée à des mutations dans les gènes codant les chaînes de collagène de type IV. Nephrol Ther 2016; 12:544-551. [DOI: 10.1016/j.nephro.2016.09.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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27
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Wu Y, Hu P, Xu H, Yuan J, Yuan L, Xiong W, Deng X, Deng H. A novel heterozygous COL4A4 missense mutation in a Chinese family with focal segmental glomerulosclerosis. J Cell Mol Med 2016; 20:2328-2332. [PMID: 27469977 PMCID: PMC5134383 DOI: 10.1111/jcmm.12924] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 06/12/2016] [Indexed: 01/15/2023] Open
Abstract
Focal segmental glomerulosclerosis (FSGS) is the most common glomerular histological lesion associated with high-grade proteinuria and end-stage renal disease. Histologically, FSGS is characterized by focal segmental sclerosis with foot process effacement. The aim of this study was to identify the disease-causing mutation in a four-generation Chinese family with FSGS. A novel missense mutation, c.1856G>A (p.Gly619Asp), in the collagen type IV alpha-4 gene (COL4A4) was identified in six patients and it co-segregated with the disease in this family. The variant is predicted to be disease-causing and results in collagen IV abnormalities. Our finding broadens mutation spectrum of the COL4A4 gene and extends the phenotypic spectrum of collagen IV nephropathies. Our study suggests that exome sequencing is a cost-effective and efficient approach for identification of disease-causing mutations in phenotypically complex or equivocal disorders. Timely screening for COL4A3/COL4A4 mutations in patients with familial FSGS may help both accurately diagnose and treat these patients.
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Affiliation(s)
- Yuan Wu
- Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China.,Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China.,Department of Clinical Laboratory, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Pengzhi Hu
- Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China.,Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China.,Department of Radiology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Hongbo Xu
- Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China.,Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Jinzhong Yuan
- Department of Nephrology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Lamei Yuan
- Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China.,Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Wei Xiong
- Cancer Research Institute, Xiangya School of Medicine, Central South University, Changsha, China
| | - Xiong Deng
- Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China.,Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Hao Deng
- Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China.,Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China
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Weber S, Strasser K, Rath S, Kittke A, Beicht S, Alberer M, Lange-Sperandio B, Hoyer PF, Benz MR, Ponsel S, Weber LT, Klein HG, Hoefele J. Identification of 47 novel mutations in patients with Alport syndrome and thin basement membrane nephropathy. Pediatr Nephrol 2016; 31:941-55. [PMID: 26809805 DOI: 10.1007/s00467-015-3302-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Revised: 12/08/2015] [Accepted: 12/10/2015] [Indexed: 01/26/2023]
Abstract
BACKGROUND Alport syndrome (ATS) is a progressive hereditary nephropathy characterized by hematuria and proteinuria. It can be associated with extrarenal manifestations. In contrast, thin basement membrane nephropathy (TBMN) is characterized by microscopic hematuria, is largely asymptomatic, and is rarely associated with proteinuria and end-stage renal disease. Mutations have been identified in the COL4A5 gene in ATS and in the COL4A3 and COL4A4 genes in ATS and TBMN. To date, more than 1000 different mutations in COL4A5, COL4A3, and COL4A4 are known. METHODS In this study mutational analysis by exon sequencing and multiplex ligation-dependent probe amplification was performed in a large European cohort of families with ATS and TBMN. RESULTS Molecular diagnostic testing of 216 individuals led to the detection of 47 novel mutations, thereby expanding the spectrum of known mutations causing ATS and TBMN by up to 10 and 6%, respectively, depending on the database. Remarkably, a high number of ATS patients with only single mutations in COL4A3 and COL4A4 were identified. Additionally, three ATS patients presented with synonymous sequence variants that possible affect correct mRNA splicing, as suggested by in silico analysis. CONCLUSIONS The results of this study clearly broaden the genotypic spectrum of known mutations for ATS and TBMN, which will in turn now facilitate future studies into genotype-phenotype correlations. Further studies should also examine the significance of single heterozygous mutations in COL4A3 and COL4A4 and of synonymous sequence variants associated with ATS.
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Affiliation(s)
- Stefanie Weber
- Pediatric Nephrology, Pediatrics II, University of Duisburg-Essen, Essen, Germany
| | - Katja Strasser
- Pediatric Nephrology, Pediatrics II, University of Duisburg-Essen, Essen, Germany
| | - Sabine Rath
- Center for Human Genetics and Laboratory Diagnostics Dr. Klein, Dr. Rost and Colleagues, Martinsried, Germany
| | - Achim Kittke
- Center for Human Genetics and Laboratory Diagnostics Dr. Klein, Dr. Rost and Colleagues, Martinsried, Germany
| | - Sonja Beicht
- Center for Human Genetics and Laboratory Diagnostics Dr. Klein, Dr. Rost and Colleagues, Martinsried, Germany
| | - Martin Alberer
- Department of Infectious Diseases and Tropical Medicine, Ludwig-Maximilians University, Munich, Germany
| | - Bärbel Lange-Sperandio
- Pediatric Nephrology, University Children's Hospital, Ludwig-Maximilians University, Munich, Germany
| | - Peter F Hoyer
- Pediatric Nephrology, Pediatrics II, University of Duisburg-Essen, Essen, Germany
| | - Marcus R Benz
- Pediatric Nephrology, University Children's Hospital, Cologne, Germany
| | - Sabine Ponsel
- Pediatric Nephrology, University Children's Hospital, Ludwig-Maximilians University, Munich, Germany
| | - Lutz T Weber
- Pediatric Nephrology, University Children's Hospital, Cologne, Germany
| | - Hanns-Georg Klein
- Center for Human Genetics and Laboratory Diagnostics Dr. Klein, Dr. Rost and Colleagues, Martinsried, Germany
| | - Julia Hoefele
- Center for Human Genetics and Laboratory Diagnostics Dr. Klein, Dr. Rost and Colleagues, Martinsried, Germany. .,Institute of Human Genetics, Technische Universität München, Munich, Germany.
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Yuan L, Xu H, Yuan J, Deng X, Xiong W, Yang Z, Huang Y, Deng H. A novel FN1 variant associated with familial hematuria: TBMN? Clin Biochem 2016; 49:816-20. [PMID: 26968105 DOI: 10.1016/j.clinbiochem.2016.01.026] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2015] [Revised: 12/17/2015] [Accepted: 01/05/2016] [Indexed: 12/19/2022]
Abstract
OBJECTIVE Thin basement membrane nephropathy (TBMN), an autosomal dominant inherited condition in general, is characterized clinically by persistent hematuria and pathologically by thinning of glomerular basement membrane. TBMN is occasionally accompanied with proteinuria, hypertension and renal impairment in some cases. The aim of this study is to explore the genetic defect in a Chinese pedigree with familial hematuria. DESIGN AND METHODS A four-generation Chinese Han pedigree with familial hematuria was recruited. Exome sequencing was conducted in the proband diagnosed as TBMN, followed by verification in the proband and other family members with Sanger sequencing. RESULTS A novel missense variant, c.4616C>G (p.S1539C), in the fibronectin 1 gene (FN1), was identified, and it co-segregated with the disease condition in the family. It was not observed in 100 normal controls. CONCLUSIONS A missense variant in the FN1 gene is possibly responsible for familial hematuria or TBMN in this family, which may broaden the phenotype and mutation spectrums of the FN1 gene. A male patient in this family progressed to end-stage renal disease requiring kidney transplantation, supporting that familial hematuria or TBMN may not always be as benign as generally thought. The findings may have new implications for clinical monitoring and genetic counseling of the family, and may also help understand the pathogenesis.
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Affiliation(s)
- Lamei Yuan
- Center for Experimental Medicine and Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Hongbo Xu
- Center for Experimental Medicine and Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Jinzhong Yuan
- Department of Nephrology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Xiong Deng
- Center for Experimental Medicine and Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Wei Xiong
- Cancer Research Institute, Xiangya School of Medicine, Central South University, Changsha, China
| | - Zhijian Yang
- Center for Experimental Medicine and Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Yuzhou Huang
- Center for Experimental Medicine and Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Hao Deng
- Center for Experimental Medicine and Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China.
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30
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Kovács G, Kalmár T, Endreffy E, Ondrik Z, Iványi B, Rikker C, Haszon I, Túri S, Sinkó M, Bereczki C, Maróti Z. Efficient Targeted Next Generation Sequencing-Based Workflow for Differential Diagnosis of Alport-Related Disorders. PLoS One 2016; 11:e0149241. [PMID: 26934356 PMCID: PMC4775026 DOI: 10.1371/journal.pone.0149241] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2015] [Accepted: 01/28/2016] [Indexed: 01/02/2023] Open
Abstract
Alport syndrome (AS) is an inherited type IV collagen nephropathies characterized by microscopic hematuria during early childhood, the development of proteinuria and progression to end-stage renal disease. Since choosing the right therapy, even before the onset of proteinuria, can delay the onset of end-stage renal failure and improve life expectancy, the earliest possible differential diagnosis is desired. Practically, this means the identification of mutation(s) in COL4A3-A4-A5 genes. We used an efficient, next generation sequencing based workflow for simultaneous analysis of all three COL4A genes in three individuals and fourteen families involved by AS or showing different level of Alport-related symptoms. We successfully identified mutations in all investigated cases, including 14 unpublished mutations in our Hungarian cohort. We present an easy to use unified clinical/diagnostic terminology and workflow not only for X-linked but for autosomal AS, but also for Alport-related diseases. In families where a diagnosis has been established by molecular genetic analysis, the renal biopsy may be rendered unnecessary.
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Affiliation(s)
- Gábor Kovács
- University of Szeged, Faculty of Medicine, Department of Pediatrics and Pediatric Health Center, Szeged, Hungary
| | - Tibor Kalmár
- University of Szeged, Faculty of Medicine, Department of Pediatrics and Pediatric Health Center, Szeged, Hungary
| | - Emőke Endreffy
- University of Szeged, Faculty of Medicine, Department of Pediatrics and Pediatric Health Center, Szeged, Hungary
| | - Zoltán Ondrik
- University of Szeged, Faculty of Medicine, First Department of Internal Medicine, Szeged, Hungary
| | - Béla Iványi
- University of Szeged, Faculty of Medicine, Department of Pathology, Szeged, Hungary
| | - Csaba Rikker
- Péterfy Sándor Hospital Department of Internal Medicine 1, Budapest, Hungary
| | - Ibolya Haszon
- University of Szeged, Faculty of Medicine, Department of Pediatrics and Pediatric Health Center, Szeged, Hungary
| | - Sándor Túri
- University of Szeged, Faculty of Medicine, Department of Pediatrics and Pediatric Health Center, Szeged, Hungary
| | - Mária Sinkó
- University of Szeged, Faculty of Medicine, Department of Pediatrics and Pediatric Health Center, Szeged, Hungary
| | - Csaba Bereczki
- University of Szeged, Faculty of Medicine, Department of Pediatrics and Pediatric Health Center, Szeged, Hungary
| | - Zoltán Maróti
- University of Szeged, Faculty of Medicine, Department of Pediatrics and Pediatric Health Center, Szeged, Hungary
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31
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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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32
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Papazachariou L, Demosthenous P, Pieri M, Papagregoriou G, Savva I, Stavrou C, Zavros M, Athanasiou Y, Ioannou K, Patsias C, Panagides A, Potamitis C, Demetriou K, Prikis M, Hadjigavriel M, Kkolou M, Loukaidou P, Pastelli A, Michael A, Lazarou A, Arsali M, Damianou L, Goutziamani I, Soloukides A, Yioukas L, Elia A, Zouvani I, Polycarpou P, Pierides A, Voskarides K, Deltas C. Frequency of COL4A3/COL4A4 mutations amongst families segregating glomerular microscopic hematuria and evidence for activation of the unfolded protein response. Focal and segmental glomerulosclerosis is a frequent development during ageing. PLoS One 2014; 9:e115015. [PMID: 25514610 PMCID: PMC4267773 DOI: 10.1371/journal.pone.0115015] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Accepted: 11/17/2014] [Indexed: 12/29/2022] Open
Abstract
Familial glomerular hematuria(s) comprise a genetically heterogeneous group of conditions which include Alport Syndrome (AS) and thin basement membrane nephropathy (TBMN). Here we investigated 57 Greek-Cypriot families presenting glomerular microscopic hematuria (GMH), with or without proteinuria or chronic kidney function decline, but excluded classical AS. We specifically searched the COL4A3/A4 genes and identified 8 heterozygous mutations in 16 families (28,1%). Eight non-related families featured the founder mutation COL4A3-p.(G1334E). Renal biopsies from 8 patients showed TBMN and focal segmental glomerulosclerosis (FSGS). Ten patients (11.5%) reached end-stage kidney disease (ESKD) at ages ranging from 37-69-yo (mean 50,1-yo). Next generation sequencing of the patients who progressed to ESKD failed to reveal a second mutation in any of the COL4A3/A4/A5 genes, supporting that true heterozygosity for COL4A3/A4 mutations predisposes to CRF/ESKD. Although this could be viewed as a milder and late-onset form of autosomal dominant AS, we had no evidence of ultrastructural features or extrarenal manifestations that would justify this diagnosis. Functional studies in cultured podocytes transfected with wild type or mutant COL4A3 chains showed retention of mutant collagens and differential activation of the unfolded protein response (UPR) cascade. This signifies the potential role of the UPR cascade in modulating the final phenotype in patients with collagen IV nephropathies.
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Affiliation(s)
- Louiza Papazachariou
- Molecular Medicine Research Center and Laboratory of Molecular and Medical Genetics, University of Cyprus, Nicosia, Cyprus
| | - Panayiota Demosthenous
- Molecular Medicine Research Center and Laboratory of Molecular and Medical Genetics, University of Cyprus, Nicosia, Cyprus
| | - Myrtani Pieri
- Molecular Medicine Research Center and Laboratory of Molecular and Medical Genetics, University of Cyprus, Nicosia, Cyprus
| | - Gregory Papagregoriou
- Molecular Medicine Research Center and Laboratory of Molecular and Medical Genetics, University of Cyprus, Nicosia, Cyprus
| | - Isavella Savva
- Molecular Medicine Research Center and Laboratory of Molecular and Medical Genetics, University of Cyprus, Nicosia, Cyprus
| | | | - Michael Zavros
- Department of Nephrology, Nicosia General Hospital, Nicosia, Cyprus
| | | | - Kyriakos Ioannou
- Department of Nephrology, Nicosia General Hospital, Nicosia, Cyprus
| | | | - Alexia Panagides
- Department of Nephrology, Nicosia General Hospital, Nicosia, Cyprus
| | - Costas Potamitis
- Department of Nephrology, Nicosia General Hospital, Nicosia, Cyprus
| | | | - Marios Prikis
- Department of Nephrology, Nicosia General Hospital, Nicosia, Cyprus
| | | | - Maria Kkolou
- Department of Nephrology, Larnaca General Hospital, Larnaca, Cyprus
| | | | | | - Aristos Michael
- Department of Nephrology, Limassol General Hospital, Limassol, Cyprus
| | - Akis Lazarou
- Department of Nephrology, Limassol General Hospital, Limassol, Cyprus
| | - Maria Arsali
- Department of Nephrology, Limassol General Hospital, Limassol, Cyprus
| | - Loukas Damianou
- Department of Nephrology, Limassol General Hospital, Limassol, Cyprus
| | | | | | - Lakis Yioukas
- Department of Nephrology, Paphos General Hospital, Paphos, Cyprus
| | - Avraam Elia
- Department of Pediatrics, Archbishop Makarios III Hospital, Nicosia, Cyprus
| | - Ioanna Zouvani
- Department of Histopathology, Nicosia General Hospital, Nicosia, Cyprus
| | | | - Alkis Pierides
- Department of Nephrology, Hippocrateon Hospital, Nicosia, Cyprus
- * E-mail: (CD); (A. Pierides)
| | - Konstantinos Voskarides
- Molecular Medicine Research Center and Laboratory of Molecular and Medical Genetics, University of Cyprus, Nicosia, Cyprus
| | - Constantinos Deltas
- Molecular Medicine Research Center and Laboratory of Molecular and Medical Genetics, University of Cyprus, Nicosia, Cyprus
- * E-mail: (CD); (A. Pierides)
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33
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Nabais Sá MJ, Storey H, Flinter F, Nagel M, Sampaio S, Castro R, Araújo JA, Gaspar MA, Soares C, Oliveira A, Henriques AC, da Costa AG, Abreu CP, Ponce P, Alves R, Pinho L, Silva SE, de Moura CP, Mendonça L, Carvalho F, Pestana M, Alves S, Carvalho F, Oliveira JP. Collagen type IV-related nephropathies in Portugal: pathogenic COL4A3 and COL4A4 mutations and clinical characterization of 25 families. Clin Genet 2014; 88:456-61. [PMID: 25307543 DOI: 10.1111/cge.12521] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2014] [Revised: 10/04/2014] [Accepted: 10/06/2014] [Indexed: 12/22/2022]
Abstract
Pathogenic mutations in genes COL4A3/COL4A4 are responsible for autosomal Alport syndrome (AS) and thin basement membrane nephropathy (TBMN). We used Sanger sequencing to analyze all exons and splice site regions of COL4A3/COL4A4, in 40 unrelated Portuguese probands with clinical suspicion of AS/TBMN. To assess genotype-phenotype correlations, we compared clinically relevant phenotypes/outcomes between homozygous/compound heterozygous and apparently heterozygous patients. Seventeen novel and four reportedly pathogenic COL4A3/COL4A4 mutations were identified in 62.5% (25/40) of the probands. Regardless of the mutated gene, all patients with ARAS manifested chronic renal failure (CRF) and hearing loss, whereas a minority of the apparently heterozygous patients had CRF or extrarenal symptoms. CRF was diagnosed at a significantly younger age in patients with ARAS. In our families, the occurrence of COL4A3/COL4A4 mutations was higher, while the prevalence of XLAS was lower than expected. Overall, a pathogenic COL4A3/COL4A4/COL4A5 mutation was identified in >50% of patients with fewer than three of the standard diagnostic criteria of AS. With such a population background, simultaneous next-generation sequencing of all three genes may be recommended as the most expedite approach to diagnose collagen IV-related glomerular basement membrane nephropathies.
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Affiliation(s)
- M J Nabais Sá
- Department of Genetics, Faculty of Medicine, Porto, Portugal.,Unit of Research and Development of Nephrology (FCT-725), Faculty of Medicine, University of Porto, Porto, Portugal
| | - H Storey
- Molecular Genetics Laboratory, Viapath, UK
| | - F Flinter
- Genetics Centre, Guy's and St. Thomas' Hospital National Health Service Foundation Trust, London, UK
| | - M Nagel
- Center for Nephrology and Metabolic Diseases, Weisswasser, Germany
| | - S Sampaio
- Unit of Research and Development of Nephrology (FCT-725), Faculty of Medicine, University of Porto, Porto, Portugal.,Department of Nephrology, Hospital de São João, Porto, Portugal
| | - R Castro
- Department of Nephrology, Centro Hospitalar de Trás-os-Montes e Alto Douro, Vila Real, Portugal
| | - J A Araújo
- Department of Nephrology, Hospital dos Marmeleiros, Funchal, Portugal
| | - M A Gaspar
- Dialysis Clinic, NephroCare Restelo, Fresenius Medical Care, Lisboa, Portugal
| | - C Soares
- Department of Nephrology, Hospital de Braga, Braga, Portugal
| | - A Oliveira
- Dialysis Clinic Paredes, Diaverum, Paredes, Portugal
| | - A C Henriques
- Dialysis Clinic, NephroCare Braga, Fresenius Medical Care, Braga, Portugal
| | - A G da Costa
- Department of Nephrology, Hospital de Santa Maria, Lisboa, Portugal
| | - C P Abreu
- Dialysis Clinic Lumiar, Diaverum, Lisboa, Portugal
| | - P Ponce
- Dialysis Clinic, NephroCare Lumiar, Fresenius Medical Care, Lisboa, Portugal
| | - R Alves
- Dialysis Clinic, NephroCare Viseu, Fresenius Medical Care, Viseu, Portugal
| | - L Pinho
- Dialysis Clinic Paredes, Diaverum, Paredes, Portugal
| | - S E Silva
- Department of Ophthalmology, Porto, Portugal
| | - C P de Moura
- Department of Otolaryngology, Porto, Portugal.,Medical Genetics Outpatient Clinic, Hospital de São João, Porto, Portugal
| | - L Mendonça
- Department of Ophthalmology, Hospital de Braga, Braga, Portugal
| | - F Carvalho
- Unit of Renal Morphology, Department of Nephrology, Hospital Curry Cabral, Lisboa, Portugal
| | - M Pestana
- Unit of Research and Development of Nephrology (FCT-725), Faculty of Medicine, University of Porto, Porto, Portugal.,Department of Nephrology, Hospital de São João, Porto, Portugal
| | - S Alves
- Department of Genetics, Faculty of Medicine, Porto, Portugal
| | - F Carvalho
- Department of Genetics, Faculty of Medicine, Porto, Portugal
| | - J P Oliveira
- Department of Genetics, Faculty of Medicine, Porto, Portugal.,Unit of Research and Development of Nephrology (FCT-725), Faculty of Medicine, University of Porto, Porto, Portugal.,Medical Genetics Outpatient Clinic, Hospital de São João, Porto, Portugal
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Xiu X, Yuan J, Deng X, Xiao J, Xu H, Zeng Z, Guan L, Xu F, Deng S. A novel COL4A5 mutation identified in a Chinese Han family using exome sequencing. BIOMED RESEARCH INTERNATIONAL 2014; 2014:186048. [PMID: 25110662 PMCID: PMC4109303 DOI: 10.1155/2014/186048] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Accepted: 06/20/2014] [Indexed: 11/17/2022]
Abstract
Alport syndrome (AS) is a monogenic disease of the basement membrane (BM), resulting in progressive renal failure due to glomerulonephropathy, variable sensorineural hearing loss, and ocular anomalies. It is caused by mutations in the collagen type IV alpha-3 gene (COL4A3), the collagen type IV alpha-4 gene (COL4A4), and the collagen type IV alpha-5 gene (COL4A5), which encodes type IV collagen α3, α4, and α5 chains, respectively. To explore the disease-related gene in a four-generation Chinese Han pedigree of AS, exome sequencing was conducted on the proband, and a novel deletion mutation c.499delC (p.Pro167Glnfs*36) in the COL4A5 gene was identified. This mutation, absent in 1,000 genomes project, HapMap, dbSNP132, YH1 databases, and 100 normal controls, cosegregated with patients in the family. Neither sensorineural hearing loss nor typical COL4A5-related ocular abnormalities (dot-and-fleck retinopathy, anterior lenticonus, and the rare posterior polymorphous corneal dystrophy) were present in patients of this family. The phenotypes of patients in this AS family were characterized by early onset-age and rapidly developing into end-stage renal disease (ESRD). Our discovery broadens the mutation spectrum in the COL4A5 gene associated with AS, which may also shed new light on genetic counseling for AS.
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Affiliation(s)
- Xiaofei Xiu
- Center for Experimental Medicine and Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, China
- Department of Pharmacy, Xiangya Hospital, Central South University, Xiangya Road 87, Kaifu District, Changsha, Hunan 410008, China
| | - Jinzhong Yuan
- Department of Nephrology, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, China
| | - Xiong Deng
- Center for Experimental Medicine and Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, China
| | | | - Hongbo Xu
- Center for Experimental Medicine and Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, China
| | - Zhaoyang Zeng
- Cancer Research Institute, Xiangya Medical School of Central South University, Changsha, Hunan 410008, China
| | - Liping Guan
- BGI-Shenzhen, Shenzhen, Guangdong 518083, China
| | - Fengping Xu
- BGI-Shenzhen, Shenzhen, Guangdong 518083, China
| | - Sheng Deng
- Center for Experimental Medicine and Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, China
- Department of Pharmacy, Xiangya Hospital, Central South University, Xiangya Road 87, Kaifu District, Changsha, Hunan 410008, China
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35
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Deltas C, Pierides A, Voskarides K. Molecular genetics of familial hematuric diseases. Nephrol Dial Transplant 2013; 28:2946-60. [PMID: 24046192 DOI: 10.1093/ndt/gft253] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The familial hematuric diseases are a genetically heterogeneous group of monogenic conditions, caused by mutations in one of several genes. The major genes involved are the following: (i) the collagen IV genes COL4A3/A4/A5 that are expressed in the glomerular basement membranes (GBM) and are responsible for the most frequent forms of microscopic hematuria, namely Alport syndrome (X-linked or autosomal recessive) and thin basement membrane nephropathy (TBMN). (ii) The FN1 gene, expressed in the glomerulus and responsible for a rare form of glomerulopathy with fibronectin deposits (GFND). (iii) CFHR5 gene, a recently recognized regulator of the complement alternative pathway and mutated in a recently revisited form of inherited C3 glomerulonephritis (C3GN), characterized by isolated C3 deposits in the absence of immune complexes. A hallmark feature of all conditions is the age-dependent penetrance and a broad phenotypic heterogeneity in the sense that subsets of patients progress to added proteinuria or proteinuria and chronic renal failure that may or may not lead to end-stage kidney disease (ESKD) anywhere between the second and seventh decade of life. In addition to other excellent laboratory tools that assist the clinician in reaching the correct diagnosis, the molecular analysis emerges as the gold standard in establishing the diagnosis in many cases of doubt due to equivocal findings that complicate the differential diagnosis. Recent work led to the description of candidate genetic modifiers which confer a variable risk for progressing to chronic renal failure when co-inherited on the background of a primary glomerulopathy. Finally, more families are still waiting to be studied and more genes to be mapped and cloned that are responsible for other forms of heritable hematuric diseases. The study of such genes and their protein products will likely shed more light on the structure and function of the glomerular filtration barrier and other important glomerular components.
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Affiliation(s)
- Constantinos Deltas
- Molecular Medicine Research Center and Laboratory of Molecular and Medical Genetics, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus
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36
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Voskarides K, Demosthenous P, Papazachariou L, Arsali M, Athanasiou Y, Zavros M, Stylianou K, Xydakis D, Daphnis E, Gale DP, Maxwell PH, Elia A, Pattaro C, Pierides A, Deltas C. Epistatic role of the MYH9/APOL1 region on familial hematuria genes. PLoS One 2013; 8:e57925. [PMID: 23516419 PMCID: PMC3597641 DOI: 10.1371/journal.pone.0057925] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Accepted: 01/27/2013] [Indexed: 11/18/2022] Open
Abstract
Familial hematuria (FH) is explained by at least four different genes (see below). About 50% of patients develop late proteinuria and chronic kidney disease (CKD). We hypothesized that MYH9/APOL1, two closely linked genes associated with CKD, may be associated with adverse progression in FH. Our study included 102 thin basement membrane nephropathy (TBMN) patients with three known COL4A3/COL4A4 mutations (cohort A), 83 CFHR5/C3 glomerulopathy patients (cohort B) with a single CFHR5 mutation and 15 Alport syndrome patients (cohort C) with two known COL4A5 mild mutations, who were categorized as “Mild” (controls) or “Severe” (cases), based on renal manifestations. E1 and S1 MYH9 haplotypes and variant rs11089788 were analyzed for association with disease phenotype. Evidence for association with “Severe” progression in CFHR5 nephropathy was found with MYH9 variant rs11089788 and was confirmed in an independent FH cohort, D (cumulative p value = 0.001, odds ratio = 3.06, recessive model). No association was found with APOL1 gene. Quantitative Real time PCR did not reveal any functional significance for the rs11089788 risk allele. Our results derive additional evidence supporting previous reports according to which MYH9 is an important gene per se, predisposing to CKD, suggesting its usefulness as a prognostic marker for young hematuric patients.
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Affiliation(s)
- Konstantinos Voskarides
- Molecular Medicine Research Center and Laboratory of Molecular and Medical Genetics, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus
| | - Panayiota Demosthenous
- Molecular Medicine Research Center and Laboratory of Molecular and Medical Genetics, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus
| | - Louiza Papazachariou
- Molecular Medicine Research Center and Laboratory of Molecular and Medical Genetics, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus
| | - Maria Arsali
- Department of Nephrology, Nicosia General Hospital, Nicosia, Cyprus
| | | | - Michalis Zavros
- Department of Nephrology, Nicosia General Hospital, Nicosia, Cyprus
| | - Kostas Stylianou
- Department of Nephrology, University of Crete, Heraklion, Greece
| | - Dimitris Xydakis
- Department of Nephrology, University of Crete, Heraklion, Greece
| | - Eugenios Daphnis
- Department of Nephrology, University of Crete, Heraklion, Greece
| | - Daniel P. Gale
- Centre for Nephrology, University College London, London, United Kingdom
| | | | - Avraam Elia
- Department of Pediatrics, Archbishop Makarios III Hospital, Nicosia, Cyprus
| | - Cristian Pattaro
- Institute of Genetic Medicine, European Academy Bozen/Bolzano (EURAC), Bolzano, Italy – Affiliated Institute of the University of Lubeck, Lubeck, Germany
| | - Alkis Pierides
- Department of Nephrology, Hippocrateon Hospital, Nicosia, Cyprus
| | - Constantinos Deltas
- Molecular Medicine Research Center and Laboratory of Molecular and Medical Genetics, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus
- * E-mail:
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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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Zhang Y, Wang F, Ding J, Zhang H, Zhao D, Yu L, Xiao H, Yao Y, Zhong X, Wang S. Genotype-phenotype correlations in 17 Chinese patients with autosomal recessive Alport syndrome. Am J Med Genet A 2012; 158A:2188-93. [PMID: 22887978 DOI: 10.1002/ajmg.a.35528] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Accepted: 05/19/2012] [Indexed: 11/11/2022]
Abstract
Autosomal recessive Alport syndrome (ARAS) results from mutations in the COL4A3 or COL4A4 gene. We analyzed the genotype and phenotype of 17 unrelated Chinese patients with ARAS. Clinical data were reviewed. All coding exons of COL4A3 and COL4A4 genes were PCR-amplified and sequenced from genomic DNA. We identified pathologic mutations in all patients, giving a mutation detection rate of 100%, with 82% in COL4A3 gene and 18% in COL4A4 gene. Sixteen novel mutations in COL4A3 gene and four novel mutations in COL4A4 gene were identified. Furthermore, a previously reported in-frame deletion mutation (40_63del24) in exon 1 of the COL4A3 gene was found in four patients in our study. A single 40_63del24 mutation in COL4A3 seems to result in mild or no renal manifestations, whereas the homozygous state of 40_63del24 in COL4A3 gene or compound heterozygous mutation of 40_63del24 plus another nonsense or frameshift mutation in COL4A3 gene seems to result severe ARAS with hearing loss. Half of the probands' parents had hematuria with or without mild proteinuria. Therefore, we recommend that ARAS be considered when a patient has a positive family history of hematuria, and screening for COL4A3 mutations firstly may be an efficient strategy for molecular diagnosis of ARAS.
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Affiliation(s)
- Yanqin Zhang
- Department of Pediatrics, Peking University First Hospital, Beijing, PR China
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Meguro A, Ideta H, Ota M, Ito N, Ideta R, Yonemoto J, Takeuchi M, Uemoto R, Nishide T, Iijima Y, Kawagoe T, Okada E, Shiota T, Hagihara Y, Oka A, Inoko H, Mizuki N. Common variants in the COL4A4 gene confer susceptibility to lattice degeneration of the retina. PLoS One 2012; 7:e39300. [PMID: 22723992 PMCID: PMC3378527 DOI: 10.1371/journal.pone.0039300] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2012] [Accepted: 05/17/2012] [Indexed: 11/18/2022] Open
Abstract
Lattice degeneration of the retina is a vitreoretinal disorder characterized by a visible fundus lesion predisposing the patient to retinal tears and detachment. The etiology of this degeneration is still uncertain, but it is likely that both genetic and environmental factors play important roles in its development. To identify genetic susceptibility regions for lattice degeneration of the retina, we performed a genome-wide association study (GWAS) using a dense panel of 23,465 microsatellite markers covering the entire human genome. This GWAS in a Japanese cohort (294 patients with lattice degeneration and 294 controls) led to the identification of one microsatellite locus, D2S0276i, in the collagen type IV alpha 4 (COL4A4) gene on chromosome 2q36.3. To validate the significance of this observation, we evaluated the D2S0276i region in the GWAS cohort and in an independent Japanese cohort (280 patients and 314 controls) using D2S0276i and 47 single nucleotide polymorphisms covering the region. The strong associations were observed in D2S0276i and rs7558081 in the COL4A4 gene (Pc = 5.8 × 10(-6), OR = 0.63 and Pc = 1.0 × 10(-5), OR = 0.69 in a total of 574 patients and 608 controls, respectively). Our findings suggest that variants in the COL4A4 gene may contribute to the development of lattice degeneration of the retina.
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Affiliation(s)
- Akira Meguro
- Department of Ophthalmology and Visual Science, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, Japan
| | | | - Masao Ota
- Department of Legal Medicine, Shinshu University School of Medicine, Matsumoto, Nagano, Japan
| | - Norihiko Ito
- Department of Ophthalmology and Visual Science, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, Japan
| | | | - Junichi Yonemoto
- Department of Ophthalmology and Visual Science, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, Japan
| | - Masaki Takeuchi
- Department of Ophthalmology and Visual Science, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, Japan
| | - Riyo Uemoto
- Department of Ophthalmology and Visual Science, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, Japan
| | - Tadayuki Nishide
- Department of Ophthalmology and Visual Science, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, Japan
| | - Yasuhito Iijima
- Department of Ophthalmology and Visual Science, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, Japan
| | - Tatsukata Kawagoe
- Department of Ophthalmology and Visual Science, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, Japan
| | | | - Tomoko Shiota
- Department of Ophthalmology and Visual Science, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, Japan
| | - Yuta Hagihara
- Department of Ophthalmology and Visual Science, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, Japan
| | - Akira Oka
- Division of Molecular Life Science, Department of Genetic Information, Tokai University School of Medicine, Isehara, Kanagawa, Japan
| | - Hidetoshi Inoko
- Division of Molecular Life Science, Department of Genetic Information, Tokai University School of Medicine, Isehara, Kanagawa, Japan
| | - Nobuhisa Mizuki
- Department of Ophthalmology and Visual Science, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, Japan
- * E-mail:
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The role of molecular genetics in diagnosing familial hematuria(s). Pediatr Nephrol 2012; 27:1221-31. [PMID: 21688191 PMCID: PMC3382641 DOI: 10.1007/s00467-011-1935-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Revised: 05/24/2011] [Accepted: 05/25/2011] [Indexed: 01/18/2023]
Abstract
Familial microscopic hematuria (MH) of glomerular origin represents a heterogeneous group of monogenic conditions involving several genes, some of which remain unknown. Recent advances have increased our understanding and our ability to use molecular genetics for diagnosing such patients, enabling us to study their clinical characteristics over time. Three collagen IV genes, COL4A3, COL4A4, and COL4A5 explain the autosomal and X-linked forms of Alport syndrome (AS), and a subset of thin basement membrane nephropathy (TBMN). A number of X-linked AS patients follow a milder course reminiscent of that of patients with heterozygous COL4A3/COL4A4 mutations and TBMN, while at the same time a significant subset of patients with TBMN and familial MH progress to chronic kidney disease (CKD) or end-stage kidney disease (ESKD). A mutation in CFHR5, a member of the complement factor H family of genes that regulate complement activation, was recently shown to cause isolated C3 glomerulopathy, presenting with MH in childhood and demonstrating a significant risk for CKD/ESKD after 40 years old. Through these results molecular genetics emerges as a powerful tool for a definite diagnosis when all the above conditions enter the differential diagnosis, while in many at-risk related family members, a molecular diagnosis may obviate the need for another renal biopsy.
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Athanasiou Y, Voskarides K, Gale DP, Damianou L, Patsias C, Zavros M, Maxwell PH, Cook HT, Demosthenous P, Hadjisavvas A, Kyriacou K, Zouvani I, Pierides A, Deltas C. Familial C3 glomerulopathy associated with CFHR5 mutations: clinical characteristics of 91 patients in 16 pedigrees. Clin J Am Soc Nephrol 2011; 6:1436-46. [PMID: 21566112 DOI: 10.2215/cjn.09541010] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND AND OBJECTIVES Complement factor H and related proteins (CFHR) are key regulators of the alternative complement pathway, where loss of function mutations lead to a glomerulopathy with isolated mesangial C3 deposits without immunoglobulins. Gale et al. (12) reported on 26 patients with the first familial, hematuric glomerulopathy caused by a founder mutation in the CFHR5 gene in patients of Cypriot descent living in the United Kingdom. CFHR5 nephropathy is clinically characterized by continuous microscopic hematuria whereas some patients present with additional episodes of synpharyngitic macrohematuria, associated with infection and pyrexia. A subgroup of patients, particularly men, develop additional proteinuria, hypertension, and chronic renal disease or ESRD. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS We herewith expand significantly on the study by Gale et al., reporting on histologic, molecular, and clinical findings in 91 patients from 16 families with the same founder mutation. RESULTS Eighty-two patients (90%) exhibited microscopic hematuria; 51 (62%), exhibited only microscopic hematuria, whereas the remaining 31 additionally had proteinuria (38%); 28 proteinuric patients developed chronic renal failure (CRF). Among carriers of CFHR5 mutation aged >50 years, 80% of the men and 21% of the women developed CRF; 18 developed ESRD (14 men [78%], 4 women [22%]). CONCLUSIONS The diagnosis of CFHR5-related, isolated C3 glomerulopathy was established in 2009 using newly described mutation analysis after decades of follow-up with unclear diagnoses, occasionally confused with IgA nephropathy. This larger patient cohort establishes the clinical course, significant variable expressivity, and marked gender difference regarding the development of CRF and ESRD.
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Ma J, Pan X, Wang Z, Wang Y, Feng X, Ren H, Zhang W, Chen X, Wang W, Chen N. Twenty-one novel mutations identified in the COL4A5 gene in Chinese patients with X-linked Alport's syndrome confirmed by skin biopsy. Nephrol Dial Transplant 2011; 26:4003-10. [PMID: 21505094 DOI: 10.1093/ndt/gfr184] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND The clinical and pathological features of Alport syndrome are characterized by abnormalities in the basement membrane collagen network which are composed of the α3, α4 and α5 chains of type IV collagen and usually associated with hearing loss and ocular lesions. The predominant form (85% of AS) is inherited as X-linked mode (XLAS) caused by mutations encoding the α5 chain of type IV collagen gene, COL4A5. Different mutations in the COL4A5 gene have been reported widely, but only a few mutations were identified in Chinese patients. METHODS We studied 71 Chinese patients from 35 unrelated families with XLAS confirmed by skin biopsy. Genomic DNA was extracted from peripheral blood of all patients. All 51 exons of the COL4A5 gene were screened by direct sequencing for the probands. RESULTS A total of twenty-five identified gene mutations were considered to be pathogenic, including 1 nonsense, 1 splice-site, 1 complex rearrangement, 5 small deletions, 2 small insertions and 15 missense mutations. Twenty-one mutations have not been reported previously. CONCLUSIONS We have identified 25 pathogenic mutations in 35 Chinese families with XLAS. Skin biopsy is effective for the diagnosis of XLAS.
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Affiliation(s)
- Jun Ma
- Department of Nephrology, Shanghai Jiaotong University School of Medicine, Shanghai, China
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Demosthenous P, Voskarides K, Stylianou K, Hadjigavriel M, Arsali M, Patsias C, Georgaki E, Zirogiannis P, Stavrou C, Daphnis E, Pierides A, Deltas C. X-linked Alport syndrome in Hellenic families: phenotypic heterogeneity and mutations near interruptions of the collagen domain in COL4A5. Clin Genet 2011; 81:240-8. [PMID: 21332469 DOI: 10.1111/j.1399-0004.2011.01647.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The X-linked Alport syndrome (ATS) is caused by mutations in COL4A5 and exhibits a widely variable expression. Usually ATS is heralded with continuous microhematuria which rapidly progresses to proteinuria, hypertension and chronic or end-stage renal disease (ESRD) by adolescence, frequently accompanied by sensorineural deafness and ocular complications. Milder forms of ATS also exist. We studied 42 patients (19M, 23F) of nine Hellenic families suspected clinically of X-linked ATS who presented with marked phenotypic heterogeneity. We identified mutations in COL4A5 in six families. Two males with nonsense mutation E228X reached ESRD by ages 14 and 18. Frameshift mutation 2946delT followed the same course with early onset renal involvement and deafness. However, two males with the milder missense mutation G624D, reached ESRD after 39 years and one patient showed thin basement membrane nephropathy (TBMN). Another 5/8 affected males with missense mutation P628L also developed ESRD between 30 and 57 years, while three exhibit only mild chronic renal failure (CRF). The data support previous findings that certain mutations are associated with milder phenotypes and confirm that mutation G624D may be expressed as TBMN with familial hematuria. Similar conclusions apply for missense mutation P628L. Interestingly, mutations G624D and P628L are near the 12th natural interruption of COL4A5 triple helical domain, which may explain the milder phenotype.
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Affiliation(s)
- P Demosthenous
- Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus
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Abstract
Endogenous inhibitors of angiogenesis are proteins or fragments of proteins that are formed in the body, which can inhibit the angiogenic process. These molecules can be found both in the circulation and sequestered in the extracellular matrix (ECM) surrounding cells. Many matrix-derived inhibitors of angiogenesis, such as endostatin, tumstatin, canstatin and arresten, are bioactive fragments of larger ECM molecules. These substances become released upon proteolysis of the ECM and the vascular basement membrane (VBM) by enzymes of the tumor microenvironment. Although the role of matrix-derived angiogenesis inhibitors is well studied in animal models of cancer, their role in human cancers is less established. In this review we discuss the current knowledge about these molecules and their potential use as cancer therapeutics and biomarkers.
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Kaneko K, Tanaka S, Hasui M, Nozu K, Krol RP, Iijima K, Sugimoto K, Takemura T. A family with X-linked benign familial hematuria. Pediatr Nephrol 2010; 25:545-8. [PMID: 19937058 DOI: 10.1007/s00467-009-1370-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2009] [Revised: 10/19/2009] [Accepted: 10/22/2009] [Indexed: 11/24/2022]
Abstract
Gene mutations in COL4A5 located on Xq22 are believed to cause X-linked Alport syndrome, whereas mutations in COL4A3 and COL4A4 located on chromosome 2 are associated with autosomal inherited Alport syndrome or benign familial hematuria. A family with benign familial hematuria caused by COL4A5 mutation, implying X-linked transmission, is reported here for the first time. This result suggests that COL4A5 should be added to the list of causative genes for benign familial hematuria, although the mechanism(s) by which the same mutation leads to the distinct phenotypes, i.e. X-linked Alport syndrome or benign familial hematuria, remains unknown.
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Affiliation(s)
- Kazunari Kaneko
- Department of Pediatrics, Kansai Medical University, 2-3-1 Shin-machi, Hirakata-shi, Osaka 573-1191, Japan.
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Marcocci E, Uliana V, Bruttini M, Artuso R, Silengo MC, Zerial M, Bergesio F, Amoroso A, Savoldi S, Pennesi M, Giachino D, Rombolà G, Fogazzi GB, Rosatelli C, Martinhago CD, Carmellini M, Mancini R, Di Costanzo G, Longo I, Renieri A, Mari F. Autosomal dominant Alport syndrome: molecular analysis of the COL4A4 gene and clinical outcome. Nephrol Dial Transplant 2009; 24:1464-71. [PMID: 19129241 DOI: 10.1093/ndt/gfn681] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Alport syndrome is a clinically and genetically heterogeneous nephropathy characterized by glomerular basement membrane lesions often associated with hearing loss and ocular anomalies. While the X-linked and the autosomal recessive forms are well known, the autosomal dominant form is not well acknowledged. METHODS We have clinically investigated 38 patients with a diagnosis of autosomal dominant Alport syndrome belonging to eight different families. The analysis of the COL4A4 gene was performed by denaturing high performance liquid chromatography and automated DNA sequencing. RESULTS In our cohort of patients, only 24.3% (9/37) reached end-stage renal disease, at the mean age of 51.2 years. Four patients had hearing loss (13.3%) and none ocular changes. Molecular analysis revealed eight novel private COL4A4 gene mutations: three frameshift, three missense and two splice-site mutations. CONCLUSIONS These data indicate autosomal dominant Alport syndrome as a disease with a low risk of ocular and hearing anomalies but with a significant risk to develop renal failure although at an older age than the X-linked form. We were unable to demonstrate a genotype-phenotype correlation. Altogether, these data make difficult the differential diagnosis with the benign familial haematuria due to heterozygous mutations of COL4A4 and COL4A3, especially in young patients, and with the X-linked form of Alport syndrome in families where only females are affected. A correct diagnosis and prognosis is based on a comprehensive clinical investigation in as many family members as possible associated with a broadly formal genetic analysis of the pedigree.
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Affiliation(s)
- Elena Marcocci
- Medical Genetics, Department of Molecular Biology, University of Siena, Siena, Italy
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Detection of large deletion mutations in the COL4A5 gene of female Alport syndrome patients. Pediatr Nephrol 2008; 23:2085-90. [PMID: 18584212 DOI: 10.1007/s00467-008-0878-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/29/2008] [Revised: 04/04/2008] [Accepted: 04/21/2008] [Indexed: 10/21/2022]
Abstract
Alport syndrome is the most common form of hereditary nephritis, and the majority of cases are caused by mutations in the COL4A5 gene. However, direct sequencing by polymerase chain reaction (PCR), from genomic DNA, or reverse transcriptase-polymerase chain reaction (RT-PCR), from mRNA, or polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) has reportedly resulted in detection rates of 31% to 84%, but of only 20% to 71% when restricted to female patients. This report concerns two female patients with X-linked Alport syndrome. Although mutational analysis of the COL4A5 gene was conducted with direct sequencing using genomic DNA and mRNA extracted from leukocytes, the results were negative for detection of mutations. Semi-quantitative PCR using genomic DNA was therefore conducted to detect large heterozygous deletions. The results were that the first patient showed complete loss of the COL4A5 gene and the second patient showed deletion from exons 37 to 51. Our patients possessed large heterozygous deletions in the COL4A5 gene that could not be detected with the standard direct sequencing method and were identified with semi-quantitative PCR. Previously reported mutation detection rates for female patients have been lower than overall rates. Our findings indicate that this difference may, in part, be due to failure to detect this type of mutation with conventional analytical methods.
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Voskarides K, Pierides A, Deltas C. COL4A3/COL4A4 mutations link familial hematuria and focal segmental glomerulosclerosis. glomerular epithelium destruction via basement membrane thinning? Connect Tissue Res 2008; 49:283-8. [PMID: 18661361 DOI: 10.1080/03008200802148280] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The recent description of multiple gene defects in hereditary podocytopathies and in hereditary glomerular basement membrane diseases has dramatically improved the current state of our knowledge on the renal glomerular filtration barrier. Recently described mutations in collagen IV and laminin in patients with hematuria and severe nephrotic syndrome add to other experimental data supporting the hypothesis that the glomerular basement membrane (GBM) may also have a significant role in protein filtration, a function previously attributed exclusively to the podocytes. Collagen IV heterozygous mutations were thought to cause only a mild form of renal disease (thin basement membrane nephropathy--TBMN). However, data from our laboratory show that many patients who carry such mutations may later on in life develop focal and segmental glomerulosclerosis, on top of the TBMN and the microscopic hematuria, a situation that frequently progresses to chronic renal failure or even end-stage renal disease. The role of unknown modifier genes may explain the heterogeneity of symptoms in TBMN and other glomerular diseases and in particular the selected development of chronic renal failure. The molecular communication between GBM and podocytes may also be a key factor in the search for these major genetic modifiers while their understanding may improve novel drug design for glomerular diseases.
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Voskarides K, Damianou L, Neocleous V, Zouvani I, Christodoulidou S, Hadjiconstantinou V, Ioannou K, Athanasiou Y, Patsias C, Alexopoulos E, Pierides A, Kyriacou K, Deltas C. COL4A3/COL4A4 mutations producing focal segmental glomerulosclerosis and renal failure in thin basement membrane nephropathy. J Am Soc Nephrol 2007; 18:3004-16. [PMID: 17942953 DOI: 10.1681/asn.2007040444] [Citation(s) in RCA: 147] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Mutations in the COL4A3/COL4A4 genes of type IV collagen have been found in approximately 40% of cases of thin basement membrane nephropathy, which is characterized by microscopic hematuria and is classically thought to cause proteinuria and chronic renal failure rarely. Here we report our observations of 116 subjects from 13 Cypriot families clinically affected with thin basement membrane nephropathy. These families first came to our attention because they segregated microscopic hematuria, mild proteinuria, and variable degrees of renal impairment, but a dual diagnosis of focal segmental glomerulosclerosis (FSGS) and thin basement membrane nephropathy was made in 20 biopsied cases. Molecular studies identified founder mutations in both COL4A3 and COL4A4 genes in 10 families. None of 82 heterozygous patients had any extrarenal manifestations, supporting the diagnosis of thin basement membrane nephropathy. During follow-up of up to three decades, 31 of these 82 patients (37.8%) developed chronic renal failure and 16 (19.5%) reached end-stage renal disease. Mutations G1334E and G871C were detected in seven and three families, respectively, and were probably introduced by founders. We conclude that these particular COL4A3/COL4A4 mutations either predispose some patients to FSGS and chronic renal failure, or that thin basement membrane nephropathy sometimes coexists with another genetic modifier that is responsible for FSGS and progressive renal failure. The findings presented here do not justify the labelling of thin basement membrane nephropathy as a benign condition with excellent prognosis.
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Hou P, Chen Y, Ding J, Li G, Zhang H. A novel mutation of COL4A3 presents a different contribution to Alport syndrome and thin basement membrane nephropathy. Am J Nephrol 2007; 27:538-44. [PMID: 17726307 DOI: 10.1159/000107666] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2007] [Accepted: 07/13/2007] [Indexed: 11/19/2022]
Abstract
BACKGROUND Alport syndrome (AS) and thin basement membrane nephropathy (TBMN) are heterogeneous renal hereditary diseases. Mutations of COL4A3 and COL4A4 genes were reported to be the underlying pathogenicity in both diseases. However, the mechanism of the same mutation causing totally different clinical processes and outcomes in AS and TBMN is still not clear. SUBJECTS AND METHODS Mutations of all coding exons of COL4A3 and COL4A4 were screened in a patient with autosomal recessive Alport syndrome (ARAS) of a Chinese Han consanguineous family by means of PCR and direct sequencing. Furthermore, the identified mutation was validated by restriction endonuclease AvaII in all 20 members in his family, as well as 46 patients with TBMN, 2 patients with AS from another two families, and 50 healthy controls. RESULTS A novel missense mutation (3725G>A, G1242D) in exon 42 of COL4A3 was identified in the proband in the homozygous form. This pathogenic mutation was demonstrated in all carriers who presented with hematuria or mild proteinuria in the heterozygous form, whereas it was not detected in others whose urinalysis was normal within the family. In addition, 10 polymorphisms, including 1 non-glycine missense variant and 9 neutral polymorphisms, were detected in COL4A3/COL4A4. CONCLUSION The novel mutation (3725G>A, G1242D) of COL4A3 was the underlying pathogenic role in the homozygous form in ARAS and in the heterozygous form in TBMN within an identical family. The result provided a potentially useful clue for the functional investigation of COL4A3 in these two hereditary glomerular disorders.
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Affiliation(s)
- Ping Hou
- Renal Division, Peking University First Hospital, Peking University Institute of Nephrology, Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China
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