1
|
Younsi ME, Achour A, Kraoua L, Nesrine M, Sayari T, Abderrahim E, Laabidi J, Zouaghi MK, Kharrat M, Gargah T, Trabelsi M, M'rad R. Genetic study of Alport syndrome in Tunisia. Pediatr Nephrol 2024:10.1007/s00467-024-06474-7. [PMID: 39138691 DOI: 10.1007/s00467-024-06474-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2024] [Revised: 06/13/2024] [Accepted: 07/11/2024] [Indexed: 08/15/2024]
Abstract
BACKGROUND Alport syndrome is a genetic disorder affecting the kidneys, ears, and eyes, causing chronic kidney disease, sensorineural hearing loss, and ocular abnormalities. It results from pathogenic variants in the COL4A3, COL4A4, or COL4A5 genes, with different inheritance patterns: X-linked from COL4A5 variants, autosomal recessive from homozygous variants in COL4A3 or COL4A4, digenic from variants in both COL4A3 and COL4A4, and autosomal dominant from heterozygous variants in COL4A3 or COL4A4. METHODS We analyzed 45 patients with Alport syndrome from 11 Tunisian families to determine their clinical and genetic characteristics. Clinical data were collected retrospectively, and whole-exome sequencing was conducted on one patient from each family. Sanger sequencing validated pathogenic variants, and cascade screening extended the analysis to 53 individuals. RESULTS We identified nine likely pathogenic variants among 11 index cases: six novel and three known variations. Of these, five were in COL4A3, and four were in COL4A5, with variants including frameshift, nonsense, missense, and alternative splicing. Most variations affected the Gly-XY codon. Among the 45 clinically identified siblings, 30 tested positive for Alport syndrome. The cascade screening identified 3 additional affected individuals, 10 unaffected siblings, and 10 unaffected parents. The mode of inheritance was autosomal recessive in six families and X-linked in four families. CONCLUSIONS This study is the first to screen the mutational spectrum of Alport syndrome in Tunisia. It reveals novel pathogenic variants and suggests that autosomal recessive inheritance may be more common in the Tunisian population than X-linked inheritance, contrary to existing literature.
Collapse
Affiliation(s)
- Mariem El Younsi
- Laboratoire de Génétique Humaine, Faculté de Médecine de Tunis, Université de Tunis El Manar, LR99ES101007, Tunis, Tunisia
| | - Ahlem Achour
- Laboratoire de Génétique Humaine, Faculté de Médecine de Tunis, Université de Tunis El Manar, LR99ES101007, Tunis, Tunisia
- Service des Maladies Congénitales Et Héréditaires, Hôpital Charles Nicolle, 1006, Tunis, Tunisia
| | - Lilia Kraoua
- Laboratoire de Génétique Humaine, Faculté de Médecine de Tunis, Université de Tunis El Manar, LR99ES101007, Tunis, Tunisia
- Service des Maladies Congénitales Et Héréditaires, Hôpital Charles Nicolle, 1006, Tunis, Tunisia
| | - Mezzi Nesrine
- Laboratory of Biomedical Genomics and Oncogenetics, Pasteur Institute of Tunis, 1002, Tunis, Tunisia
| | - Taha Sayari
- Service de Néphrologie Pédiatrique, Hôpital Charles Nicolle, 1006, Tunis, Tunisia
| | - Ezzeddine Abderrahim
- Service de Médecine Interne Et de Néphrologie Adulte, Hôpital Charles Nicolle, 1006, Tunis, Tunisia
| | - Janet Laabidi
- Service Néphrologie, L'Hôpital Militaire Principal d'Instruction de Tunis, MontFleury, 1008, Tunis, Tunisia
| | - Mohamed Karim Zouaghi
- Service de Néphrologie, Dialyse Et Transplantation Rénale, Hôpital La Rabta 1007, Tunis, Tunisia
| | - Maher Kharrat
- Laboratoire de Génétique Humaine, Faculté de Médecine de Tunis, Université de Tunis El Manar, LR99ES101007, Tunis, Tunisia
| | - Tahar Gargah
- Service de Néphrologie Pédiatrique, Hôpital Charles Nicolle, 1006, Tunis, Tunisia
| | - Mediha Trabelsi
- Laboratoire de Génétique Humaine, Faculté de Médecine de Tunis, Université de Tunis El Manar, LR99ES101007, Tunis, Tunisia
- Service des Maladies Congénitales Et Héréditaires, Hôpital Charles Nicolle, 1006, Tunis, Tunisia
| | - Ridha M'rad
- Laboratoire de Génétique Humaine, Faculté de Médecine de Tunis, Université de Tunis El Manar, LR99ES101007, Tunis, Tunisia.
- Service des Maladies Congénitales Et Héréditaires, Hôpital Charles Nicolle, 1006, Tunis, Tunisia.
| |
Collapse
|
2
|
Puapatanakul P, Miner JH. Alport syndrome and Alport kidney diseases - elucidating the disease spectrum. Curr Opin Nephrol Hypertens 2024; 33:283-290. [PMID: 38477333 PMCID: PMC10990029 DOI: 10.1097/mnh.0000000000000983] [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: 03/14/2024]
Abstract
PURPOSE OF REVIEW With the latest classification, variants in three collagen IV genes, COL4A3 , COL4A4 , and COL4A5 , represent the most prevalent genetic kidney disease in humans, exhibiting diverse, complex, and inconsistent clinical manifestations. This review breaks down the disease spectrum and genotype-phenotype correlations of kidney diseases linked to genetic variants in these genes and distinguishes "classic" Alport syndrome (AS) from the less severe nonsyndromic genetically related nephropathies that we suggest be called "Alport kidney diseases". RECENT FINDINGS Several research studies have focused on the genotype-phenotype correlation under the latest classification scheme of AS. The historic diagnoses of "benign familial hematuria" and "thin basement membrane nephropathy" linked to heterozygous variants in COL4A3 or COL4A4 are suggested to be obsolete, but instead classified as autosomal AS by recent expert consensus due to a significant risk of disease progression. SUMMARY The concept of Alport kidney disease extends beyond classic AS. Patients carrying pathogenic variants in any one of the COL4A3/A4/A5 genes can have variable phenotypes ranging from completely normal/clinically unrecognizable, hematuria without or with proteinuria, or progression to chronic kidney disease and kidney failure, depending on sex, genotype, and interplays of other genetic as well as environmental factors.
Collapse
Affiliation(s)
- Pongpratch Puapatanakul
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
- Division of Nephrology, Department of Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Jeffrey H. Miner
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| |
Collapse
|
3
|
Zhu RL, Zhao L, Gu XP, Zhang YD, Wang F, Zhang YQ, Yang L. Temporal retinal thinning might be an early diagnostic indicator in male pediatric X-linked Alport syndrome. Int J Ophthalmol 2022; 15:1142-1148. [PMID: 35919312 DOI: 10.18240/ijo.2022.07.15] [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: 11/15/2021] [Accepted: 05/18/2022] [Indexed: 12/13/2022] Open
Abstract
AIM To evaluate temporal retinal thinning changes in retinal layers using spectral-domain optical coherence tomography (SD-OCT) in pediatric X-linked Alport syndrome (XLAS) patients. METHODS A retrospective case-control study. SD-OCT scans of pediatric patients diagnosed with XLAS and age- and sex-matched healthy control participants were reviewed. Automated segmentation of SD-OCT scans was induced to analyze the retinal thickness (RT) of different layers. The temporal thinning index (TTI) was calculated for each layer and compared between the patients and the control group. RESULTS Forty-three pediatric XLAS patients and 60 healthy controls were included. Temporal retinal thinning was present in 33 patients (76.74%), while 28 patients (65.11%) had severe pathological temporal retinal thinning and 5 patients (11.63%) had moderate thinning. The temporal inner sector RT (P<0.0001), the temporal outer sector RT (P<0.0001), and the nasal outer sector RT (P=0.0211) were significantly thinner in the XLAS male patients. The TTI of the total retina was significantly higher in the XLAS group than in the control group (P<0.0001). The TTI of the inner retina layers (P<0.0001), ganglion cell layer (P<0.0001), inner plexiform layer (P<0.0001), inner nuclear layer (P<0.0001), and outer nuclear layer (P<0.0001) were significantly higher in the XLAS group. The central RT of the XLAS group was significantly thinner than that of the control group (P<0.0001). CONCLUSION Temporal retinal thinning appears early in XLAS patients, especially in male patients. The thinning is mainly caused by structural abnormalities of the inner retina. This suggests that temporal retinal thinning could be helpful for the early diagnosis and follow-up of XLAS with noninvasive SD-OCT examination.
Collapse
Affiliation(s)
- Rui-Lin Zhu
- Department of Ophthalmology, Peking University First Hospital, Beijing 100034, China
| | - Liang Zhao
- Department of Ophthalmology, Peking University First Hospital, Beijing 100034, China
| | - Xiao-Peng Gu
- Department of Ophthalmology, Peking University First Hospital, Beijing 100034, China
| | - Ya-Di Zhang
- Department of Ophthalmology, Peking University First Hospital, Beijing 100034, China
| | - Fang Wang
- Department of Pediatrics, Peking University First Hospital, Beijing 100034, China
| | - Yan-Qin Zhang
- Department of Pediatrics, Peking University First Hospital, Beijing 100034, China
| | - Liu Yang
- Department of Ophthalmology, Peking University First Hospital, Beijing 100034, China
| |
Collapse
|
4
|
Barua M, Paterson AD. Population-based studies reveal an additive role of type IV collagen variants in hematuria and albuminuria. Pediatr Nephrol 2022; 37:253-262. [PMID: 33635378 DOI: 10.1007/s00467-021-04934-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 10/31/2020] [Accepted: 01/07/2021] [Indexed: 02/08/2023]
Abstract
Specific variants in genes that encode the α3α4α5 chains of type IV collagen cause Alport syndrome (AS), which encompass a clinical spectrum from isolated hematuria to multisystem disease affecting sight, hearing and kidney function. The commonest form is X-linked Alport syndrome (XLAS; COL4A5) with autosomal AS (COL4A3 and COL4A4) comprising a minority of cases. While historic data estimates the frequency of AS at 1:5000-10,000, recent population-based genetic studies suggest the prevalence is considerably higher. Genome-wide association studies (GWAS) have been performed in the Icelandic (deCODE) and UK (UK Biobank) populations, demonstrating an association of type IV collagen gene variants with AS relevant kidney traits. In the Icelandic population, 1 in 600 carries a 2.5-kb COL4A3 coding deletion or a COL4A3 missense variant (rs200287952[A], Gly695Arg), both of which are strongly associated with hematuria and albuminuria (P values = 1.9 × 10-5 to 2.5 × 10-20). In the UK Biobank, COL4A4 rs35138315 (Ser969X; carrier frequency 0.13%) is strongly associated with both hematuria and albuminuria (P = 1.5 × 10-73). Thus, the frequency for autosomal AS is 5-16 times higher than the historic prevalence of all forms of the disorder. Furthermore, COL4A4 rs3518315 (Ser969X) is also a reported founder mutation in families with autosomal dominant focal and segmental glomerulosclerosis and autosomal recessive forms of AS. This supports an additive mode of inheritance for specific variants, wherein a number of copies of a mutation influence disease severity in a cumulative fashion. These studies did not include the X chromosome, excluding analysis of COL4A5, which represents an area for future study.
Collapse
Affiliation(s)
- Moumita Barua
- Division of Nephrology, Toronto General Hospital, 200 Elizabeth Street, 8NU-855, Toronto, ON, M5G 2C4, Canada. .,Department of Medicine, University of Toronto, Toronto, Canada. .,Toronto General Hospital Research Institute, University Health Network, Toronto, Canada. .,Institute of Medical Sciences, University of Toronto, Toronto, Canada.
| | - Andrew D Paterson
- Institute of Medical Sciences, University of Toronto, Toronto, Canada.,Divisions of Epidemiology and Biostatistics, Dalla Lana School of Public Health, Toronto, Canada.,Genetics and Genome Biology, Research Institute at Hospital for Sick Children, Toronto, Canada
| |
Collapse
|
5
|
Chen X, Ye N, Zhang L, Zheng W, Cheng J, Gong M. Functional assessment of a novel COL4A5 splicing site variant in a Chinese X-linked Alport syndrome family. ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:1420. [PMID: 34733972 PMCID: PMC8506736 DOI: 10.21037/atm-21-3523] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 09/03/2021] [Indexed: 02/05/2023]
Abstract
Background Chronic kidney disease caused by X-linked Alport syndrome (XLAS) is relatively rare. However, due to the nonspecific pathologic and clinical manifestations of this disease, it is easily misdiagnosed. Genetic testing is crucial in identifying suspected cases. In addition, the results of genetic testing are an important indicator of patient prognosis. This study demonstrated a novel pathogenic COL4A5 splicing site variant in a Chinese family with XLAS. Methods Targeted next generation sequencing (NGS) was performed to identify the gene variant in the family members, and the gene mutation site was confirmed by Sanger sequencing. We then further analyzed the consequences of this gene mutation on the translated protein of this variant using in silico and in vitro approaches. Results A novel splice region variant, c.1033-2(IVS 18) A>G, in COL4A5 intron 18 was identified in the affected family members. Sanger sequencing confirmed that this variant is segregated with disease. In silico analysis, this variant led to frame-shift and premature termination on the translation of the nucleic acid, and this result was verified by RNA splicing analysis in a cell model. Unexpectedly, we still observed positive immunohistology staining of collagen IV α5 in the glomerular basement membrane (GBM) of the index patient, which implied that another potential transcription or translation mechanism skipping the mutated site might exist. Conclusions Our present finding expands the mutational spectrum for the COL4A5 gene associated with XLAS and highlights the genotype-phenotype correlations in this disease.
Collapse
Affiliation(s)
- Xiaolei Chen
- Department of Nephrology, West China Hospital, Sichuan University, Chengdu, China
| | - Nan Ye
- Laboratory of Proteomics and Metabolomics for Diseases, Institutes for Systems Genetics, Frontiers Science Center for Disease-Related Molecular Network, West China Hospital, Sichuan University, Chengdu, China
| | - Lu Zhang
- Laboratory of Proteomics and Metabolomics for Diseases, Institutes for Systems Genetics, Frontiers Science Center for Disease-Related Molecular Network, West China Hospital, Sichuan University, Chengdu, China
| | - Wen Zheng
- Laboratory of Proteomics and Metabolomics for Diseases, Institutes for Systems Genetics, Frontiers Science Center for Disease-Related Molecular Network, West China Hospital, Sichuan University, Chengdu, China
| | - Jingqiu Cheng
- Laboratory of Proteomics and Metabolomics for Diseases, Institutes for Systems Genetics, Frontiers Science Center for Disease-Related Molecular Network, West China Hospital, Sichuan University, Chengdu, China
| | - Meng Gong
- Laboratory of Proteomics and Metabolomics for Diseases, Institutes for Systems Genetics, Frontiers Science Center for Disease-Related Molecular Network, West China Hospital, Sichuan University, Chengdu, China
| |
Collapse
|
6
|
Genotype-phenotype correlations and nephroprotective effects of RAAS inhibition in patients with autosomal recessive Alport syndrome. Pediatr Nephrol 2021; 36:2719-2730. [PMID: 33772369 PMCID: PMC8370956 DOI: 10.1007/s00467-021-05040-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 02/20/2021] [Accepted: 03/02/2021] [Indexed: 02/06/2023]
Abstract
BACKGROUND Autosomal recessive Alport syndrome (ARAS) is caused by pathogenic variants in both alleles of either COL4A3 or COL4A4 genes. Reports on ARAS are rare due to small patient numbers and there are no reports on renin-angiotensin-aldosterone system (RAAS) inhibition therapy in ARAS. METHODS Retrospective study in 101 patients with ARAS from Chinese Registry Database of Hereditary Kidney Diseases and European Alport Registry. Genotype-phenotype correlations and nephroprotective effects of RAAS inhibition in ARAS were evaluated. RESULTS Median age was 15 years (range 1.5-46 years). Twelve patients progressed to stage 5 chronic kidney disease (CKD5) at median age 20.5 years. Patients without missense variants had both higher prevalence and earlier onset age of hearing loss, nephrotic-range proteinuria, more rapid decline of eGFR, and earlier onset age of CKD5 compared to patients with 1 or 2 missense variants. Most patients (79/101, 78%) currently are treated with RAAS inhibitors; median age at therapy initiation was 10 years and mean duration 6.5 ± 6.0 years. Median age at CKD5 for untreated patients was 24 years. RAAS inhibition therapy delayed CKD5 onset in those with impaired kidney function (T-III) to median age 35 years, but is undefined in treated patients with proteinuria (T-II) due to low number of events. No treated patients with microalbuminuria (T-I) progressed to CKD5. ARAS patients with 1 or 2 missense variants showed better response to treatment than patients with non-missense-variants. CONCLUSIONS Our study provides the first evidence for early use of RAAS inhibition therapy in patients with ARAS. Furthermore, genotype in ARAS correlates with response to therapy in favor of missense variants.
Collapse
|
7
|
Kim JJ, David JM, Wilbon SS, Santos JV, Patel DM, Ahmad A, Mitrofanova A, Liu X, Mallela SK, Ducasa GM, Ge M, Sloan AJ, Al-Ali H, Boulina M, Mendez AJ, Contreras GN, Prunotto M, Sohail A, Fridman R, Miner JH, Merscher S, Fornoni A. Discoidin domain receptor 1 activation links extracellular matrix to podocyte lipotoxicity in Alport syndrome. EBioMedicine 2020; 63:103162. [PMID: 33340991 PMCID: PMC7750578 DOI: 10.1016/j.ebiom.2020.103162] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 11/21/2020] [Accepted: 11/24/2020] [Indexed: 12/11/2022] Open
Abstract
Background Discoidin domain receptor 1 (DDR1) is a receptor tyrosine kinase that is activated by collagens that is involved in the pathogenesis of fibrotic disorders. Interestingly, de novo production of the collagen type I (Col I) has been observed in Col4a3 knockout mice, a mouse model of Alport Syndrome (AS mice). Deletion of the DDR1 in AS mice was shown to improve survival and renal function. However, the mechanisms driving DDR1-dependent fibrosis remain largely unknown. Methods Podocyte pDDR1 levels, Collagen and cluster of differentiation 36 (CD36) expression was analyzed by Real-time PCR and Western blot. Lipid droplet accumulation and content was determined using Bodipy staining and enzymatic analysis. CD36 and DDR1 interaction was determined by co-immunoprecipitation. Creatinine, BUN, albuminuria, lipid content, and histological and morphological assessment of kidneys harvested from AS mice treated with Ezetimibe and/or Ramipril or vehicle was performed. Findings We demonstrate that Col I-mediated DDR1 activation induces CD36-mediated podocyte lipotoxic injury. We show that Ezetimibe interferes with the CD36/DDR1 interaction in vitro and prevents lipotoxicity in AS mice thus preserving renal function similarly to ramipril. Interpretation Our study suggests that Col I/DDR1-mediated lipotoxicity contributes to renal failure in AS and that targeting this pathway may represent a new therapeutic strategy for patients with AS and with chronic kidney diseases (CKD) associated with Col4 mutations. Funding This study is supported by the NIH grants R01DK117599, R01DK104753, R01CA227493, U54DK083912, UM1DK100846, U01DK116101, UL1TR000460 (Miami Clinical Translational Science Institute, National Center for Advancing Translational Sciences and the National Institute on Minority Health and Health Disparities), F32DK115109, Hoffmann-La Roche and Alport Syndrome Foundation.
Collapse
Affiliation(s)
- Jin-Ju Kim
- Katz Family Division of Nephrology and Hypertension, Drug Discovery center, Department of Medicine, University of Miami Miller School of Medicine, 1580 NW 10th Ave, Miami, FL 33136, United States.
| | - Judith M David
- Katz Family Division of Nephrology and Hypertension, Drug Discovery center, Department of Medicine, University of Miami Miller School of Medicine, 1580 NW 10th Ave, Miami, FL 33136, United States
| | - Sydney S Wilbon
- Katz Family Division of Nephrology and Hypertension, Drug Discovery center, Department of Medicine, University of Miami Miller School of Medicine, 1580 NW 10th Ave, Miami, FL 33136, United States
| | - Javier V Santos
- Katz Family Division of Nephrology and Hypertension, Drug Discovery center, Department of Medicine, University of Miami Miller School of Medicine, 1580 NW 10th Ave, Miami, FL 33136, United States
| | - Devang M Patel
- Department of Diabetes, Central Clinical School, Monash University, Melbourne, Australia
| | - Anis Ahmad
- Department of Radiation Oncology, University of Miami, FL 33136, United States
| | - Alla Mitrofanova
- Katz Family Division of Nephrology and Hypertension, Drug Discovery center, Department of Medicine, University of Miami Miller School of Medicine, 1580 NW 10th Ave, Miami, FL 33136, United States; Department of Surgery, University of Miami Miller School of Medicine, Miami, FL 33136, United States
| | - Xiaochen Liu
- Katz Family Division of Nephrology and Hypertension, Drug Discovery center, Department of Medicine, University of Miami Miller School of Medicine, 1580 NW 10th Ave, Miami, FL 33136, United States
| | - Shamroop K Mallela
- Katz Family Division of Nephrology and Hypertension, Drug Discovery center, Department of Medicine, University of Miami Miller School of Medicine, 1580 NW 10th Ave, Miami, FL 33136, United States
| | - Gloria M Ducasa
- Katz Family Division of Nephrology and Hypertension, Drug Discovery center, Department of Medicine, University of Miami Miller School of Medicine, 1580 NW 10th Ave, Miami, FL 33136, United States
| | - Mengyuan Ge
- Katz Family Division of Nephrology and Hypertension, Drug Discovery center, Department of Medicine, University of Miami Miller School of Medicine, 1580 NW 10th Ave, Miami, FL 33136, United States
| | - Alexis J Sloan
- Katz Family Division of Nephrology and Hypertension, Drug Discovery center, Department of Medicine, University of Miami Miller School of Medicine, 1580 NW 10th Ave, Miami, FL 33136, United States
| | - Hassan Al-Ali
- Katz Family Division of Nephrology and Hypertension, Drug Discovery center, Department of Medicine, University of Miami Miller School of Medicine, 1580 NW 10th Ave, Miami, FL 33136, United States
| | - Marcia Boulina
- Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, FL 33136, United States
| | - Armando J Mendez
- Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, FL 33136, United States
| | - Gabriel N Contreras
- Katz Family Division of Nephrology and Hypertension, Drug Discovery center, Department of Medicine, University of Miami Miller School of Medicine, 1580 NW 10th Ave, Miami, FL 33136, United States
| | - Marco Prunotto
- Roche Pharma Research and Early Development, Roche Innovation Center, Basel, Switzerland; School of Pharmaceutical Sciences, University of Geneva, Geneva, Switzerland
| | - Anjum Sohail
- Department of Pathology, Wayne State University School of Medicine, Detroit, Michigan 48201, United States
| | - Rafael Fridman
- Department of Pathology, Wayne State University School of Medicine, Detroit, Michigan 48201, United States
| | - Jeffrey H Miner
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110, United States
| | - Sandra Merscher
- Katz Family Division of Nephrology and Hypertension, Drug Discovery center, Department of Medicine, University of Miami Miller School of Medicine, 1580 NW 10th Ave, Miami, FL 33136, United States
| | - Alessia Fornoni
- Katz Family Division of Nephrology and Hypertension, Drug Discovery center, Department of Medicine, University of Miami Miller School of Medicine, 1580 NW 10th Ave, Miami, FL 33136, United States.
| |
Collapse
|
8
|
Weinstock BA, Feldman DL, Fornoni A, Gross O, Kashtan CE, Lagas S, Lennon R, Miner JH, Rheault MN, Simon JF. Clinical trial recommendations for potential Alport syndrome therapies. Kidney Int 2020; 97:1109-1116. [PMID: 32386680 PMCID: PMC7614298 DOI: 10.1016/j.kint.2020.02.029] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 02/04/2020] [Accepted: 02/12/2020] [Indexed: 12/26/2022]
Abstract
Alport syndrome is experiencing a remarkable increase in preclinical investigations. To proactively address the needs of the Alport syndrome community, as well as offer clarity for future clinical research sponsors, the Alport Syndrome Foundation hosted a workshop to generate consensus recommendations for prospective trials for conventional drugs. Opinions of key stakeholders were carefully considered, including those of the biopharmaceutical industry representatives, academic researchers, clinicians, regulatory agency representatives, and-most critically-patients with Alport syndrome. Recommendations were established for preclinical researchers, the use and selection of biomarkers, standards of care, clinical trial designs, trial eligibility criteria and outcomes, pediatric trial considerations, and considerations for patient engagement, recruitment, and treatment. This paper outlines their recommendations.
Collapse
Affiliation(s)
| | | | - Alessia Fornoni
- Katz Family Division of Nephrology and Hypertension, Miller School of Medicine, University of Miami, Miami, Florida, USA
| | - Oliver Gross
- Department of Nephrology and Rheumatology, Universitätsmedizin Göttingen, Göttingen, Germany
| | - Clifford E Kashtan
- Department of Pediatrics, University of Minnesota Medical School, Minneapolis, Minnesota, USA
| | - Sharon Lagas
- Alport Syndrome Foundation, Phoenix, Arizona, USA
| | - Rachel Lennon
- Division of Cell Matrix Biology & Regenerative Medicine, University of Manchester, Manchester, England, UK.
| | - Jeffrey H Miner
- Division of Nephrology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Michelle N Rheault
- Department of Pediatrics, University of Minnesota Medical School, Minneapolis, Minnesota, USA
| | - James F Simon
- Department of Nephrology and Hypertension, The Cleveland Clinic, Cleveland, Ohio, USA
| | | |
Collapse
|
9
|
Nath M, Gireesh P. Femtosecond laser-assisted cataract surgery in Alport's syndrome - A case report. Indian J Ophthalmol 2020; 67:1891-1893. [PMID: 31638065 PMCID: PMC6836590 DOI: 10.4103/ijo.ijo_586_19] [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] [Indexed: 12/03/2022] Open
Abstract
Alport's syndrome with anterior lenticonus poses significant challenges during capsulorhexis with high chances of peripheral extension. We report a case of 23-year-old lady with Alport's syndrome with anterior lenticonus in the left eye that underwent successful femtosecond laser-assisted cataract surgery (FLACS). The anterior lenticonus was eccentric nasally; hence, the FLACS capsulotomy was positioned slightly nasally so that the capsulotomy margin was outside the cone base. The distance vision improved from 6/24 to 6/6 at one-month follow-up. In summary, FLACS improved the safety of cataract surgery in an eye with anterior lenticonus and yielded excellent visual outcomes.
Collapse
Affiliation(s)
- Manas Nath
- Department of Cataract Services, Aravind Eye Hospital and Post Graduate Institute of Ophthalmology, Pondicherry, India
| | - Prasanth Gireesh
- Department of Cataract Services, Aravind Eye Hospital and Post Graduate Institute of Ophthalmology, Pondicherry, India
| |
Collapse
|
10
|
Rheault MN, Savige J, Randles MJ, Weinstock A, Stepney M, Turner AN, Parziale G, Gross O, Flinter FA, Miner JH, Lagas S, Gear S, Lennon R. The importance of clinician, patient and researcher collaborations in Alport syndrome. Pediatr Nephrol 2020; 35:733-742. [PMID: 31044288 PMCID: PMC7096363 DOI: 10.1007/s00467-019-04241-7] [Citation(s) in RCA: 11] [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: 02/24/2019] [Accepted: 03/15/2019] [Indexed: 12/19/2022]
Abstract
Alport syndrome is caused by mutations in the genes COL4A3, COL4A4 or COL4A5 and is characterised by progressive glomerular disease, sensorineural hearing loss and ocular defects. Occurring in less than 1:5000, Alport syndrome is a rare genetic disorder but still accounts for > 1% of the prevalent population receiving renal replacement therapy. There is also increasing awareness about the risk of chronic kidney disease in individuals with heterozygous mutations in Alport syndrome genes. The mainstay of current therapy is the use of angiotensin-converting enzyme inhibitors and angiotensin receptor blockers, yet potential new therapies are now entering clinical trials. The 2017 International Workshop on Alport Syndrome in Glasgow was a pre-conference workshop ahead of the 50th anniversary meeting of the European Society for Pediatric Nephrology. It focussed on updates in clinical practice, genetics and basic science and also incorporated patient perspectives. More than 80 international experts including clinicians, geneticists, researchers from academia and industry, and patient representatives took part in panel discussions and breakout groups. This report summarises the workshop proceedings and the relevant contemporary literature. It highlights the unique clinician, patient and researcher collaborations achieved by regular engagement between the groups.
Collapse
Affiliation(s)
- Michelle N. Rheault
- Department of Pediatrics, University of Minnesota Masonic Children’s Hospital, Minneapolis, MN USA
| | - Judith Savige
- Department of Medicine, Royal Melbourne Hospital, Victoria, Australia
| | - Michael J. Randles
- Wellcome Centre for Cell-Matrix Research, Division of Cell Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology Medicine and Health, University of Manchester, Manchester, UK
| | | | - Melissa Stepney
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
| | - A Neil Turner
- Renal Medicine, Royal Infirmary, University of Edinburgh, Edinburgh, UK
| | | | - Oliver Gross
- Clinic of Nephrology and Rheumatology, University Medicine Goettingen, Goettingen, Germany
| | - Frances A Flinter
- Department of Clinical Genetics, Guy’s & St Thomas’ NHS Foundation Trust, London, UK
| | - Jeffrey H Miner
- Division of Nephrology, Washington University School of Medicine, St Louis, MO USA
| | | | | | - Rachel Lennon
- Wellcome Centre for Cell-Matrix Research, Division of Cell Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology Medicine and Health, University of Manchester, Manchester, UK. .,Department of Paediatric Nephrology, Royal Manchester Children's Hospital, Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK.
| |
Collapse
|
11
|
Umesawa M, Hara M, Sairenchi T, Nagao M, Haruyama Y, Kobashi G. Relationships between dipstick proteinuria and risk of hearing impairment among Japanese workers: a prospective cohort study. BMJ Open 2019; 9:e028767. [PMID: 31678936 PMCID: PMC6830626 DOI: 10.1136/bmjopen-2018-028767] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
OBJECTIVES Hearing impairment is among the most significant health problems, and the number of adults with hearing impairment is increasing worldwide. Therefore, the prevention of hearing impairment is important. Proteinuria appears to be a risk factor for hearing impairment, but no prospective studies have examined the association between proteinuria and hearing impairment risk. This prospective study aimed to clarify the association between dipstick proteinuria and risk of hearing impairment. DESIGN This was a prospective cohort study based on annual health check-up data, 2008-2016. SETTING Data were collected on 7005 employees of a single company who worked in offices and factories throughout Japan. PARTICIPANTS We analysed data from 5699 subjects (88.6% men) who underwent annual health check-ups twice or more from 2008 to 2016, had no missing data, and were free from hearing impairment at baseline. We regarded the first health check-up as the baseline examination. PRIMARY AND SECONDARY OUTCOME MEASURES Hearing tests were performed using audiometry at two frequencies (1 and 4 kHz) during the health check-ups. Defining total moderate hearing impairment as the inability to respond to 30 dB at 1 kHz and/or 40 dB at 4 kHz, we examined the association between dipstick proteinuria at baseline and risk of hearing impairment at final examination. RESULTS Total moderate hearing impairment was noted in 162 (2.8%) subjects. Compared with subjects without proteinuria at baseline, the multivariable adjusted OR (95% CI) was 5.35 (1.87-15.25) for subjects with proteinuria ≥2+, 0.92 (0.40-2.13) for those with proteinuria +/-, and 1.33 (0.63-2.80) for those with proteinuria+ at baseline. CONCLUSIONS Severe dipstick proteinuria was positively associated with risk of hearing impairment in the future. Our results suggest that medical examinations including urine testing are effective for detecting subjects with high risk of hearing impairment.
Collapse
Affiliation(s)
- Mitsumasa Umesawa
- Department of Public Health, Dokkyo Medical University School of Medicine, Mibu, Tochigi, Japan
| | | | - Toshimi Sairenchi
- Department of Public Health, Dokkyo Medical University School of Medicine, Mibu, Tochigi, Japan
| | - Masanori Nagao
- Department of Public Health, Dokkyo Medical University School of Medicine, Mibu, Tochigi, Japan
| | - Yasuo Haruyama
- Department of Public Health, Dokkyo Medical University School of Medicine, Mibu, Tochigi, Japan
| | - Gen Kobashi
- Department of Public Health, Dokkyo Medical University School of Medicine, Mibu, Tochigi, Japan
| |
Collapse
|
12
|
Herrington WG, Staplin N, Haynes R. Kidney disease trials for the 21st century: innovations in design and conduct. Nat Rev Nephrol 2019; 16:173-185. [PMID: 31673162 DOI: 10.1038/s41581-019-0212-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/18/2019] [Indexed: 12/11/2022]
Abstract
Compared to other specialties, nephrology has reported relatively few clinical trials, and most of these are too small to detect moderate treatment effects. Consequently, interventions that are commonly used by nephrologists have not been adequately tested and some may be ineffective or harmful. More randomized trials are urgently needed to address important clinical questions in patients with kidney disease. The use of robust surrogate markers may accelerate early-phase drug development. However, scientific innovations in trial conduct developed by other specialties should also be adopted to improve trial quality and enable more, larger trials in kidney disease to be completed in the current era of burdensome regulation and escalating research costs. Examples of such innovations include utilizing routinely collected health-care data and disease-specific registries to identify and invite potential trial participants, and for long-term follow-up; use of prescreening to facilitate rapid recruitment of participants; use of pre-randomization run-in periods to improve participant adherence and assess responses to study interventions prior to randomization; and appropriate use of statistics to monitor studies and analyse their results. Nephrology is well positioned to harness such innovations due to its advanced use of electronic health-care records and the development of disease-specific registries. Adopting a population approach and efficient trial conduct along with challenging unscientific regulation may increase the number of definitive clinical trials in nephrology and improve the care of current and future patients.
Collapse
Affiliation(s)
- William G Herrington
- Medical Research Council Population Health Research Unit at the University of Oxford, Clinical Trial Service Unit and Epidemiological Studies Unit (CTSU), Nuffield Department of Population Health, Oxford, UK.,Oxford Kidney Unit, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Natalie Staplin
- Medical Research Council Population Health Research Unit at the University of Oxford, Clinical Trial Service Unit and Epidemiological Studies Unit (CTSU), Nuffield Department of Population Health, Oxford, UK
| | - Richard Haynes
- Medical Research Council Population Health Research Unit at the University of Oxford, Clinical Trial Service Unit and Epidemiological Studies Unit (CTSU), Nuffield Department of Population Health, Oxford, UK. .,Oxford Kidney Unit, Oxford University Hospitals NHS Foundation Trust, Oxford, UK.
| |
Collapse
|
13
|
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.
Collapse
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
| | | |
Collapse
|
14
|
Nephroprotektive Therapie am Beispiel des Alport-Syndroms. Monatsschr Kinderheilkd 2019. [DOI: 10.1007/s00112-018-0641-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
15
|
Suranyi E, Nagy V, Berta A, Matyus J, Szalai E, Ujhelyi B, Meleg J, Damjanovich J. Alport Patients without Classic Ocular Symptoms Have Smaller Lens Diameter. Med Sci Monit 2019; 25:2274-2277. [PMID: 30919828 PMCID: PMC6450175 DOI: 10.12659/msm.912924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Background The aim of this study was to present ophthalmological findings regarding Alport syndrome and report refractometry data and to present possible early signs of the syndrome. Material/Methods Seven patients suffering from Alport syndrome were referred to the Department of Ophthalmology at the University of Debrecen between January 1st, 2014, and December 31st, 2015. All patients underwent slit lamp evaluation and dilated fundus biomicroscopy, with special attention paid to lenticonus and retinal changes. IOL Master, Pentacam HR, and ultrasound biomicroscopy were performed to assess keratometry, corneal thickness, anterior chamber depth, lens size, and axial length data. Results One patient out of seven had ocular symptoms. Posterior polymorphous corneal dystrophy (PPMD) and dot-and-fleck retinopathy were seen. Meanwhile, although keratoconus was not proven, remarkable astigmatism with high myopia was detected. The other six patients were found to have a significantly smaller lens diameter (an average of 7.82±0.66 mm, p=0.035) compared to normal controls (an average of 8.65±0.46 mm). Lenses also tended to be thicker in Alport patients (3.48±0.19 mm) compared to controls (3.4±0.2 mm), although the difference was not significant (p=0.394). The power of the lens also showed a significant difference (p=0.026), with Alport patients having lower lens power. Conclusions Alport syndrome patients without classical ophthalmological findings have smaller crystalline lens diameter and lower lens power. These signs may support the diagnosis of Alport syndrome. Ophthalmologists should not only seek for the known classic signs, but also the parameters of the crystalline lens, especially if genetic testing is not available.
Collapse
Affiliation(s)
- Eva Suranyi
- Department of Ophthalmology, University of Debrecen, Faculty of Medicine, Debrecen, Hungary
| | - Valeria Nagy
- Department of Ophthalmology, University of Debrecen, Faculty of Medicine, Debrecen, Hungary
| | - Andras Berta
- Department of Ophthalmology, University of Debrecen, Faculty of Medicine, Debrecen, Hungary
| | - Janos Matyus
- Department of Nephrology, University of Debrecen, Faculty of Medicine, Debrecen, Hungary
| | - Eszter Szalai
- Department of Ophthalmology, University of Debrecen, Faculty of Medicine, Debrecen, Hungary
| | - Bernadett Ujhelyi
- Department of Ophthalmology, University of Debrecen, Faculty of Medicine, Debrecen, Hungary
| | - Judit Meleg
- Department of Ophthalmology, University of Debrecen, Faculty of Medicine, Debrecen, Hungary
| | - Judit Damjanovich
- Department of Ophthalmology, University of Debrecen, Faculty of Medicine, Debrecen, Hungary
| |
Collapse
|
16
|
Gross O, Hoefele J. Genetische Ursachen und Therapie beim Alport-Syndrom. MED GENET-BERLIN 2019. [DOI: 10.1007/s11825-018-0214-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Zusammenfassung
Bei der Typ IV Kollagen-Erkrankung Alport-Syndrom (AS) handelt es sich um eine progressive hereditäre Nephropathie. Klinische Zeichen sind zunächst Hämaturie und Proteinurie, im weiteren Verlauf kommt es zu einem terminalen Nierenversagen. Zusätzlich werden extrarenale Manifestationen wie Innenohr-Schwerhörigkeit und Augenveränderungen beobachtet. Man unterscheidet drei Erbgänge: 85 % der Fälle sind X-chromosomal, ca. 10 % autosomal und weniger als 5 % digenisch. Ursächlich sind Varianten in den Kollagen Typ IV-Genen COL4A3, COL4A4 (beide autosomal) und COL4A5 (X-chromosomal). Die Symptomatik heterozygoter Anlageträger wurde früher als benigne familiäre Hämaturie bezeichnet. Da Anlageträger jedoch häufig keinen benignen Verlauf zeigen, werden sie inzwischen auch unter der Diagnose „Alport-Syndrom“ geführt.
Der Humangenetiker hat daher beim AS eine wichtige Lotsenfunktion: Bei früher Diagnose ist das AS inzwischen gut behandelbar, wodurch das terminale Nierenversagen um mehrere Jahre hinausgezögert und damit die Lebenserwartung verbessert werden kann. Aufgrund der Therapiemöglichkeiten sollte die (molekulargenetische) Diagnose bei Betroffenen, auch bei heterozygoten Anlageträgern, frühzeitig gestellt werden.
Mit diesem Artikel sollen die genetischen Ursachen des AS, mögliche genetische Einflussfaktoren auf den variablen Phänotyp, die unterschiedlichen Krankheitsstadien, Komplikationen sowie die derzeit zugelassene Behandlung aufgezeigt werden, um eine bestmögliche lebenslange Betreuung des Patienten zu gewährleisten.
Collapse
Affiliation(s)
- Oliver Gross
- Aff1 0000 0001 0482 5331 grid.411984.1 Klinik für Nephrologie und Rheumatologie Universitätsmedizin Göttingen Robert-Koch Str. 40 37075 Göttingen Deutschland
| | - Julia Hoefele
- Aff2 Institut für Humangenetik Klinikum rechts der Isar, Technische Universität München Trogerstr. 32 81675 München Deutschland
| |
Collapse
|
17
|
Zhang X, Zhang Y, Zhang Y, Gu H, Chen Z, Ren L, Lu X, Chen L, Wang F, Liu Y, Ding J. X-linked Alport syndrome: pathogenic variant features and further auditory genotype-phenotype correlations in males. Orphanet J Rare Dis 2018; 13:229. [PMID: 30577881 PMCID: PMC6303895 DOI: 10.1186/s13023-018-0974-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2018] [Accepted: 12/07/2018] [Indexed: 01/06/2023] Open
Abstract
OBJECTIVE To analyze the clinical audiological characteristics of X-Linked Alport syndrome (XLAS) in males and their relationships with genotypes. METHODS The clinical data of 87 male patients with AS were reviewed. Hearing levels were evaluated using pure tone audiometry (PTA) testing, acoustic immittance, and otoacoustic emissions (OAE) testing. The genotypes of COL4A5 and the pathogenic variants were analyzed. The relationships between auditory phenotypes and genotypes were analyzed. RESULTS Among the 87 patients, the number of patients with normal hearing and hearing loss were 32 and 55, respectively. In all cases, the hearing loss was characterized as bilateral symmetrical sensorineural deafness. Majority of the patients had mild-to-moderate hearing loss. Hearing loss usually started in the middle frequency range and gradually affected high frequencies, at school age and gradually increased with increasing age. However, it maintained a relatively steady level of 50-60 dB HL during the teenage years. The audiometric curves included groove-type in 51 cases (92.73%). Patients were identified to have 60 different COL4A5 pathogenic variants. Of the 49 patients who were followed-up for more than 2 years, 28 cases presented a decreasing trend in the hearing level of about 5 dB per year. The degree of hearing loss was positively correlated with gene mutation type and renal function. CONCLUSIONS Hearing loss in males with XLAS is symmetrical sensorineural, and progressive with increasing age. There is a significant correlation between the degree of hearing loss and genotype, renal function, and age.
Collapse
Affiliation(s)
- Xiao Zhang
- Department of Otolaryngology, Head and Neck Surgery, Peking University First Hospital, Beijing, 100034 China
| | - Yanqin Zhang
- Department of Pediatrics, Peking University First Hospital, Beijing, 100034 China
| | - Yanmei Zhang
- Department of Otolaryngology, Head and Neck Surgery, Peking University First Hospital, Beijing, 100034 China
| | - Hongbo Gu
- Department of Otolaryngology, Head and Neck Surgery, Peking University First Hospital, Beijing, 100034 China
| | - Zhe Chen
- Department of Otolaryngology, Head and Neck Surgery, Peking University First Hospital, Beijing, 100034 China
| | - Lei Ren
- Department of Otolaryngology, Head and Neck Surgery, Peking University First Hospital, Beijing, 100034 China
| | - Xingxing Lu
- Department of Otolaryngology, Head and Neck Surgery, Peking University First Hospital, Beijing, 100034 China
| | - Li Chen
- Department of Otolaryngology, Head and Neck Surgery, Peking University First Hospital, Beijing, 100034 China
| | - Fang Wang
- Department of Pediatrics, Peking University First Hospital, Beijing, 100034 China
| | - Yuhe Liu
- Department of Otolaryngology, Head and Neck Surgery, Peking University First Hospital, Beijing, 100034 China
| | - Jie Ding
- Department of Pediatrics, Peking University First Hospital, Beijing, 100034 China
| |
Collapse
|
18
|
Jinagal J, Gupta G, Thattaruthody F, Nada R, Ram J. Anterior lenticonus associated with Alport syndrome. Indian J Ophthalmol 2018; 66:1330-1331. [PMID: 30127161 PMCID: PMC6113840 DOI: 10.4103/ijo.ijo_400_18] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Affiliation(s)
- Jitender Jinagal
- Advanced Eye Centre, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Gaurav Gupta
- Advanced Eye Centre, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Faisal Thattaruthody
- Advanced Eye Centre, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Ritambhra Nada
- Department of Histopathology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Jagat Ram
- Advanced Eye Centre, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| |
Collapse
|
19
|
Lin MH, Miller JB, Kikkawa Y, Suleiman HY, Tryggvason K, Hodges BL, Miner JH. Laminin-521 Protein Therapy for Glomerular Basement Membrane and Podocyte Abnormalities in a Model of Pierson Syndrome. J Am Soc Nephrol 2018; 29:1426-1436. [PMID: 29472414 PMCID: PMC5967757 DOI: 10.1681/asn.2017060690] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 01/14/2018] [Indexed: 12/22/2022] Open
Abstract
Background Laminin α5β2γ1 (LM-521) is a major component of the GBM. Mutations in LAMB2 that prevent LM-521 synthesis and/or secretion cause Pierson syndrome, a rare congenital nephrotic syndrome with diffuse mesangial sclerosis and ocular and neurologic defects. Because the GBM is uniquely accessible to plasma, which permeates endothelial cell fenestrae, we hypothesized that intravenous delivery of LM-521 could replace the missing LM-521 in the GBM of Lamb2 mutant mice and restore glomerular permselectivity.Methods We injected human LM-521 (hLM-521), a macromolecule of approximately 800 kD, into the retro-orbital sinus of Lamb2-/- pups daily. Deposition of hLM-521 into the GBM was investigated by fluorescence microscopy. We assayed the effects of hLM-521 on glomerular permselectivity by urinalysis and the effects on podocytes by desmin immunostaining and ultrastructural analysis of podocyte architecture.Results Injected hLM-521 rapidly and stably accumulated in the GBM of all glomeruli. Super-resolution imaging showed that hLM-521 accumulated in the correct orientation in the GBM, primarily on the endothelial aspect. Treatment with hLM-521 greatly reduced the expression of the podocyte injury marker desmin and attenuated the foot process effacement observed in untreated pups. Moreover, treatment with hLM-521 delayed the onset of proteinuria but did not prevent nephrotic syndrome, perhaps due to its absence from the podocyte aspect of the GBM.Conclusions These studies show that GBM composition and function can be altered in vivovia vascular delivery of even very large proteins, which may advance therapeutic options for patients with abnormal GBM composition, whether genetic or acquired.
Collapse
Affiliation(s)
- Meei-Hua Lin
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Joseph B Miller
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Yamato Kikkawa
- Department of Clinical Biochemistry, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan
| | - Hani Y Suleiman
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Karl Tryggvason
- Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, Singapore, Singapore
- Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden; and
| | | | - Jeffrey H Miner
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri;
| |
Collapse
|
20
|
Vischini G, Kapp ME, Wheeler FC, Hopp L, Fogo AB. A unique evolution of the kidney phenotype in a patient with autosomal recessive Alport syndrome. Hum Pathol 2018. [PMID: 29530752 DOI: 10.1016/j.humpath.2018.02.024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Alport syndrome is due to mutations in one of the genes encoding (α3,4,5) type IV collagen resulting in defective type IV collagen, a key component of the glomerular basement membrane (GBM). The GBM is initially thin and, with ongoing remodeling, develops a thickened basket-woven appearance. We report a unique case of a 9-year-old boy who underwent biopsy for hematuria and proteinuria, diagnosed as IgA nephropathy, with normal GBM appearance and thickness. Because of a family history of hematuria and chronic kidney disease, he subsequently underwent genetic evaluation, and a mutation of α3 type IV collagen (COL4A3) was detected. Additional studies of the initial biopsy demonstrated abnormal type IV collagen immunostaining. A repeat biopsy 4 years later showed characteristic glomerular basement membrane morphology of Alport syndrome and scarring consistent with sequelae of IgA nephropathy. This is the first description of this unusual transition from an initial normal appearance of the glomerular basement membrane to the classic Alport phenotype.
Collapse
Affiliation(s)
- Gisella Vischini
- Division of Nephrology, Department of Internal Medicine and Medical Specialities, Columbus-Gemelli University Hospital, Catholic University, Rome, Italy 00176; Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232.
| | - Meghan E Kapp
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232.
| | - Ferrin C Wheeler
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232.
| | - Laszlo Hopp
- Department of Pediatrics, Division of Nephrology, East Tennessee Children's Hospital, Knoxville, TN 37916.
| | - Agnes B Fogo
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232.
| |
Collapse
|
21
|
Omachi K, Kamura M, Teramoto K, Kojima H, Yokota T, Kaseda S, Kuwazuru J, Fukuda R, Koyama K, Matsuyama S, Motomura K, Shuto T, Suico MA, Kai H. A Split-Luciferase-Based Trimer Formation Assay as a High-throughput Screening Platform for Therapeutics in Alport Syndrome. Cell Chem Biol 2018. [PMID: 29526710 DOI: 10.1016/j.chembiol.2018.02.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Alport syndrome is a hereditary glomerular disease caused by mutation in type IV collagen α3-α5 chains (α3-α5(IV)), which disrupts trimerization, leading to glomerular basement membrane degeneration. Correcting the trimerization of α3/α4/α5 chain is a feasible therapeutic approach, but is hindered by lack of information on the regulation of intracellular α(IV) chain and the absence of high-throughput screening (HTS) platforms to assess α345(IV) trimer formation. Here, we developed sets of split NanoLuc-fusion α345(IV) proteins to monitor α345(IV) trimerization of wild-type and clinically associated mutant α5(IV). The α345(IV) trimer assay, which satisfied the acceptance criteria for HTS, enabled the characterization of intracellular- and secretion-dependent defects of mutant α5(IV). Small interfering RNA-based and chemical screening targeting the ER identified several chemical chaperones that have potential to promote α345(IV) trimer formation. This split luciferase-based trimer formation assay is a functional HTS platform that realizes the feasibility of targeting α345(IV) trimers to treat Alport syndrome.
Collapse
Affiliation(s)
- Kohei Omachi
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto City 862-0973, Kumamoto, Japan; Program for Leading Graduate School "HIGO (Health Life Science: Interdisciplinary and Glocal Oriented) Program", Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto City 862-0973, Kumamoto, Japan
| | - Misato Kamura
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto City 862-0973, Kumamoto, Japan; Program for Leading Graduate School "HIGO (Health Life Science: Interdisciplinary and Glocal Oriented) Program", Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto City 862-0973, Kumamoto, Japan
| | - Keisuke Teramoto
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto City 862-0973, Kumamoto, Japan; Program for Leading Graduate School "HIGO (Health Life Science: Interdisciplinary and Glocal Oriented) Program", Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto City 862-0973, Kumamoto, Japan
| | - Haruka Kojima
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto City 862-0973, Kumamoto, Japan
| | - Tsubasa Yokota
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto City 862-0973, Kumamoto, Japan
| | - Shota Kaseda
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto City 862-0973, Kumamoto, Japan; Program for Leading Graduate School "HIGO (Health Life Science: Interdisciplinary and Glocal Oriented) Program", Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto City 862-0973, Kumamoto, Japan
| | - Jun Kuwazuru
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto City 862-0973, Kumamoto, Japan
| | - Ryosuke Fukuda
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto City 862-0973, Kumamoto, Japan
| | - Kosuke Koyama
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto City 862-0973, Kumamoto, Japan
| | - Shingo Matsuyama
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto City 862-0973, Kumamoto, Japan
| | - Keishi Motomura
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto City 862-0973, Kumamoto, Japan
| | - Tsuyoshi Shuto
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto City 862-0973, Kumamoto, Japan
| | - Mary Ann Suico
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto City 862-0973, Kumamoto, Japan.
| | - Hirofumi Kai
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto City 862-0973, Kumamoto, Japan; Program for Leading Graduate School "HIGO (Health Life Science: Interdisciplinary and Glocal Oriented) Program", Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto City 862-0973, Kumamoto, Japan.
| |
Collapse
|
22
|
Abstract
The glomerular basement membrane (GBM) is a specialized structure with a significant role in maintaining the glomerular filtration barrier. This GBM is formed from the fusion of two basement membranes during development and its function in the filtration barrier is achieved by key extracellular matrix components including type IV collagen, laminins, nidogens, and heparan sulfate proteoglycans. The characteristics of specific matrix isoforms such as laminin-521 (α5β2γ1) and the α3α4α5 chain of type IV collagen are essential for the formation of a mature GBM and the restricted tissue distribution of these isoforms makes the GBM a unique structure. Detailed investigation of the GBM has been driven by the identification of inherited abnormalities in matrix proteins and the need to understand pathogenic mechanisms causing severe glomerular disease. A well-described hereditary GBM disease is Alport syndrome, associated with a progressive glomerular disease, hearing loss, and lens defects due to mutations in the genes COL4A3, COL4A4, or COL4A5. Other proteins associated with inherited diseases of the GBM include laminin β2 in Pierson syndrome and LMX1B in nail patella syndrome. The knowledge of these genetic mutations associated with GBM defects has enhanced our understanding of cell-matrix signaling pathways affected in glomerular disease. This review will address current knowledge of GBM-associated abnormalities and related signaling pathways, as well as discussing the advances toward disease-targeted therapies for patients with glomerular disease.
Collapse
Affiliation(s)
- Christine Chew
- Faculty of Biology Medicine and Health, Wellcome Trust Centre for Cell-Matrix Research, Division of Cell Matrix Biology, School of Biological Sciences, University of Manchester, Manchester, United Kingdom
| | - Rachel Lennon
- Faculty of Biology Medicine and Health, Wellcome Trust Centre for Cell-Matrix Research, Division of Cell Matrix Biology, School of Biological Sciences, University of Manchester, Manchester, United Kingdom.,Department of Paediatric Nephrology, Royal Manchester Children's Hospital, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, United Kingdom
| |
Collapse
|
23
|
Funk SD, Bayer RH, Malone AF, McKee KK, Yurchenco PD, Miner JH. Pathogenicity of a Human Laminin β2 Mutation Revealed in Models of Alport Syndrome. J Am Soc Nephrol 2017; 29:949-960. [PMID: 29263159 DOI: 10.1681/asn.2017090997] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2017] [Accepted: 11/19/2017] [Indexed: 01/15/2023] Open
Abstract
Pierson syndrome is a congenital nephrotic syndrome with eye and neurologic defects caused by mutations in laminin β2 (LAMB2), a major component of the glomerular basement membrane (GBM). Pathogenic missense mutations in human LAMB2 cluster in or near the laminin amino-terminal (LN) domain, a domain required for extracellular polymerization of laminin trimers and basement membrane scaffolding. Here, we investigated an LN domain missense mutation, LAMB2-S80R, which was discovered in a patient with Pierson syndrome and unusually late onset of proteinuria. Biochemical data indicated that this mutation impairs laminin polymerization, which we hypothesized to be the cause of the patient's nephrotic syndrome. Testing this hypothesis in genetically altered mice showed that the corresponding amino acid change (LAMB2-S83R) alone is not pathogenic. However, expression of LAMB2-S83R significantly increased the rate of progression to kidney failure in a Col4a3-/- mouse model of autosomal recessive Alport syndrome and increased proteinuria in Col4a5+/- females that exhibit a mild form of X-linked Alport syndrome due to mosaic deposition of collagen α3α4α5(IV) in the GBM. Collectively, these data show the pathogenicity of LAMB2-S80R and provide the first evidence of genetic modification of Alport phenotypes by variation in another GBM component. This finding could help explain the wide range of Alport syndrome onset and severity observed in patients with Alport syndrome, even for family members who share the same COL4 mutation. Our results also show the complexities of using model organisms to investigate genetic variants suspected of being pathogenic in humans.
Collapse
Affiliation(s)
- Steven D Funk
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri and
| | - Raymond H Bayer
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri and
| | - Andrew F Malone
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri and
| | - Karen K McKee
- Department of Pathology and Laboratory Medicine, Robert Wood Johnson Medical School, Rutgers University, Piscataway, New Jersey
| | - Peter D Yurchenco
- Department of Pathology and Laboratory Medicine, Robert Wood Johnson Medical School, Rutgers University, Piscataway, New Jersey
| | - Jeffrey H Miner
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri and
| |
Collapse
|
24
|
Petitjean E, Mavridou A, Li X, Hauben E, Cotti E, Lambrechts P. Multimodular assessment of a calcified extraradicular deposit on the root surfaces of a mandibular molar. Int Endod J 2017; 51:375-385. [DOI: 10.1111/iej.12855] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 08/29/2017] [Indexed: 11/29/2022]
Affiliation(s)
- E. Petitjean
- Department of Oral Health Sciences; University Hospitals Leuven; KU Leuven; Leuven Belgium
| | - A. Mavridou
- Department of Oral Health Sciences; University Hospitals Leuven; KU Leuven; Leuven Belgium
- BIOMAT; Department of Oral Health Sciences; University Hospitals Leuven; KU Leuven; Leuven Belgium
| | - X. Li
- BIOMAT; Department of Oral Health Sciences; University Hospitals Leuven; KU Leuven; Leuven Belgium
| | - E. Hauben
- Department of Imaging and Pathology; Translational Cell & Tissue Research; University Hospitals Leuven; KU Leuven; Leuven Belgium
| | - E. Cotti
- Department of Conservative Dentistry and Endodontics; School of Dentistry; University of Cagliari; Cagliari Italy
| | - P. Lambrechts
- Department of Oral Health Sciences; University Hospitals Leuven; KU Leuven; Leuven Belgium
| |
Collapse
|
25
|
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.
Collapse
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
| |
Collapse
|
26
|
Lentine KL, Kasiske BL, Levey AS, Adams PL, Alberú J, Bakr MA, Gallon L, Garvey CA, Guleria S, Li PKT, Segev DL, Taler SJ, Tanabe K, Wright L, Zeier MG, Cheung M, Garg AX. KDIGO Clinical Practice Guideline on the Evaluation and Care of Living Kidney Donors. Transplantation 2017; 101:S1-S109. [PMID: 28742762 PMCID: PMC5540357 DOI: 10.1097/tp.0000000000001769] [Citation(s) in RCA: 198] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 03/20/2017] [Indexed: 12/17/2022]
Abstract
The 2017 Kidney Disease: Improving Global Outcomes (KDIGO) Clinical Practice Guideline on the Evaluation and Care of Living Kidney Donors is intended to assist medical professionals who evaluate living kidney donor candidates and provide care before, during and after donation. The guideline development process followed the Grades of Recommendation Assessment, Development, and Evaluation (GRADE) approach and guideline recommendations are based on systematic reviews of relevant studies that included critical appraisal of the quality of the evidence and the strength of recommendations. However, many recommendations, for which there was no evidence or no systematic search for evidence was undertaken by the Evidence Review Team, were issued as ungraded expert opinion recommendations. The guideline work group concluded that a comprehensive approach to risk assessment should replace decisions based on assessments of single risk factors in isolation. Original data analyses were undertaken to produce a "proof-in-concept" risk-prediction model for kidney failure to support a framework for quantitative risk assessment in the donor candidate evaluation and defensible shared decision making. This framework is grounded in the simultaneous consideration of each candidate's profile of demographic and health characteristics. The processes and framework for the donor candidate evaluation are presented, along with recommendations for optimal care before, during, and after donation. Limitations of the evidence are discussed, especially regarding the lack of definitive prospective studies and clinical outcome trials. Suggestions for future research, including the need for continued refinement of long-term risk prediction and novel approaches to estimating donation-attributable risks, are also provided.In citing this document, the following format should be used: Kidney Disease: Improving Global Outcomes (KDIGO) Living Kidney Donor Work Group. KDIGO Clinical Practice Guideline on the Evaluation and Care of Living Kidney Donors. Transplantation. 2017;101(Suppl 8S):S1-S109.
Collapse
Affiliation(s)
| | | | | | | | - Josefina Alberú
- Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
| | | | | | | | | | | | - Dorry L. Segev
- Johns Hopkins University, School of Medicine, Baltimore, MD
| | | | | | | | | | | | | |
Collapse
|
27
|
Abstract
Most genetic disorders are clinically and genetically heterogeneous. Next-generation sequencing (NGS) has revolutionized the field and is providing rapidly growing insights into the pathomechanism of hereditary nephropathies. Current best-practice guidelines for most hereditary nephropathies include genetic diagnostics. The increasing number of genes that have to be considered in patients with hereditary nephropathies is often challenging when addressed by conventional techniques and largely benefits from NGS-based approaches that allow the parallel analysis of all disease genes in a single test at relatively low cost, e.g., by the use of multi-gene panels. Knowledge of the underlying genotype is of advantage in discussions with regard to transplantation and therapeutic options. Further, genetics may aid the early detection and treatment of renal and extrarenal complications and the reduction of invasive procedures. An accurate genetic diagnosis is crucial for genetic counselling, provides information about the recurrence risk and may help to improve the clinical management of patients and their families. The bottleneck in genetics is no longer the primary wet lab process but the interpretation of the obtained genetic data, which is by far the most challenging and work-intensive part of the analysis. This can only be managed in a multidisciplinary setting that brings together expert knowledge in genetics and the respective medical field. In the future, bench and bedside benefits can be expected from this kind of digitized medicine.
Collapse
|
28
|
Gross O, Kashtan CE, Rheault MN, Flinter F, Savige J, Miner JH, Torra R, Ars E, Deltas C, Savva I, Perin L, Renieri A, Ariani F, Mari F, Baigent C, Judge P, Knebelman B, Heidet L, Lagas S, Blatt D, Ding J, Zhang Y, Gale DP, Prunotto M, Xue Y, Schachter AD, Morton LC, Blem J, Huang M, Liu S, Vallee S, Renault D, Schifter J, Skelding J, Gear S, Friede T, Turner AN, Lennon R. Advances and unmet needs in genetic, basic and clinical science in Alport syndrome: report from the 2015 International Workshop on Alport Syndrome. Nephrol Dial Transplant 2017; 32:916-924. [PMID: 27190345 PMCID: PMC5837236 DOI: 10.1093/ndt/gfw095] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2016] [Revised: 03/21/2016] [Accepted: 03/29/2016] [Indexed: 12/27/2022] Open
Abstract
Alport syndrome (AS) is a genetic disease characterized by haematuric glomerulopathy variably associated with hearing loss and anterior lenticonus. It is caused by mutations in the COL4A3, COL4A4 or COL4A5 genes encoding the α3α4α5(IV) collagen heterotrimer. AS is rare, but it accounts for >1% of patients receiving renal replacement therapy. Angiotensin-converting enzyme inhibition slows, but does not stop, the progression to renal failure; therefore, there is an urgent requirement to expand and intensify research towards discovering new therapeutic targets and new therapies. The 2015 International Workshop on Alport Syndrome targeted unmet needs in basic science, genetics and diagnosis, clinical research and current clinical care. In three intensive days, more than 100 international experts including physicians, geneticists, researchers from academia and industry, and patient representatives from all over the world participated in panel discussions and breakout groups. This report summarizes the most important priority areas including (i) understanding the crucial role of podocyte protection and regeneration, (ii) targeting mutations by new molecular techniques for new animal models and potential gene therapy, (iii) creating optimal interaction between nephrologists and geneticists for early diagnosis, (iv) establishing standards for mutation screening and databases, (v) improving widespread accessibility to current standards of clinical care, (vi) improving collaboration with the pharmaceutical/biotech industry to investigate new therapies, (vii) research in hearing loss as a huge unmet need in Alport patients and (viii) the need to evaluate the risk and benefit of novel (including 'repurposing') therapies on an international basis.
Collapse
Affiliation(s)
- Oliver Gross
- Clinic of Nephrology and Rheumatology, University Medicine Goettingen, Goettingen, Germany
| | - Clifford E. Kashtan
- Department of Pediatrics, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Michelle N. Rheault
- Department of Pediatrics, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Frances Flinter
- Department of Clinical Genetics, Guy's and St Thomas’ NHS Foundation Trust, London, UK
| | - Judith Savige
- Melbourne Health, The University of Melbourne, Parkville, VIC, Australia
| | - Jeffrey H. Miner
- Division of Nephrology, Washington University School of Medicine, St Louis, MO, USA
| | - Roser Torra
- Inherited Kidney Diseases, Nephrology Department, Fundació Puigvert, IIB Sant Pau, Universitat Autònoma de Barcelona and REDINREN, Barcelona, Spain
| | - Elisabet Ars
- Inherited Kidney Diseases, Nephrology Department, Fundació Puigvert, IIB Sant Pau, Universitat Autònoma de Barcelona and REDINREN, Barcelona, Spain
| | - Constantinos Deltas
- Molecular Medicine Research Center, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus
| | - Isavella Savva
- Molecular Medicine Research Center, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus
| | - Laura Perin
- University of Southern California, Children's Hospital Los Angeles, Los Angeles, CA, USA
| | - Alessandra Renieri
- Medical Genetics Unit, University of Siena, Siena, Italy
- Genetica Medica, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Francesca Ariani
- Medical Genetics Unit, University of Siena, Siena, Italy
- Genetica Medica, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Francesca Mari
- Medical Genetics Unit, University of Siena, Siena, Italy
- Genetica Medica, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Colin Baigent
- Clinical Trial Service Unit and Epidemiological Studies Unit, Nuffield Department of Population Health, University of Oxford, Oxford, UK
| | - Parminder Judge
- Clinical Trial Service Unit and Epidemiological Studies Unit, Nuffield Department of Population Health, University of Oxford, Oxford, UK
| | - Bertrand Knebelman
- Division de Néphrologie, Hôpital Necker, Assistance Publique-Hôpitaux de Paris, Paris, France
- Université Paris Descartes, Paris, France
| | - Laurence Heidet
- Centre de Référence des Maladies Rénales Héréditaires de l'Enfant et de l'Adulte (MARHEA) Service de Néphrologie Pédiatrique, Clinique Maurice Lamy, Hôpital Necker-Enfants Malades, Paris, France
| | | | - Dave Blatt
- Alport Foundation of Australia, Valentine, NSW, Australia
| | - Jie Ding
- Pediatric Department, Peking University First Hospital, Beijing, China
| | - Yanqin Zhang
- Pediatric Department, Peking University First Hospital, Beijing, China
| | - Daniel P. Gale
- University College London-Centre for Nephrology, London, UK
| | - Marco Prunotto
- Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Roche Pharma Research & Early Development, Basel, Switzerland
| | - Yong Xue
- Rare Disease Group-Therapeutic Area, Global Clinical Development, Sanofi Genzyme, Naarden, The Netherlands
| | - Asher D. Schachter
- New Indications Discovery Unit, Translational Medicine, Novartis Institutes for BioMedical Research, Cambridge, MA, USA
| | - Lori C.G. Morton
- Cardiovascular Research, Fibrosis Research, Regeneron Pharmaceuticals, Tarrytown, NY, USA
| | - Jacqui Blem
- Clinical Development, Regulus Therapeutics, San Diego, CA, USA
| | - Michael Huang
- Clinical Development, Regulus Therapeutics, San Diego, CA, USA
| | - Shiguang Liu
- Department of Rare Diseases, Sanofi-Genzyme R&D Center, Framingham, MA, USA
| | | | - Daniel Renault
- Association for Information and Research on Genetic Renal Diseases (AIRG)—France, Paris, France
- Federation of European Associations of patients affected by Genetic Renal Diseases, FEDERG, Brussels, Belgium
| | | | | | | | - Tim Friede
- Department of Medical Statistics, University Medical Center Goettingen, Goettingen, Germany
| | - A. Neil Turner
- Renal Medicine, Royal Infirmary, University of Edinburgh, Edinburgh, UK
| | - Rachel Lennon
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester, Manchester, UK
| |
Collapse
|
29
|
Truong J, Deschênes G, Callard P, Antignac C, Niel O. Macroscopic hematuria with normal renal biopsy-following the chain to the diagnosis: Answers. Pediatr Nephrol 2017; 32:279-281. [PMID: 26628280 DOI: 10.1007/s00467-015-3268-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 10/27/2015] [Indexed: 11/28/2022]
Abstract
BACKGROUND Alport syndrome (AS) is an inherited glomerular disease associated with hearing and eye defects; its morbidity is a public health issue in developed countries. AS results from mutations in COL4A3, COL4A4, or COL4A5 genes, respectively encoding the alpha-3, alpha-4, and alpha-5 chains of type IV collagen, a major component of the renal glomerular basement membrane (GBM). The diagnosis is usually confirmed by a renal biopsy showing a thinning/thickening of the GBM, with a longitudinal splitting of the lamina densa. CASE DIAGNOSIS We report the case of a 10-year-old patient who presented multiple episodes of macroscopic hematuria. On the renal biopsy, the electron microscopy analysis of the GBM was normal, as was the COL4A5 immunofluorescence assay. Genetic analyses showed a homozygous duplication of exons 44 to 47 of the COL4A3 gene, confirming the diagnosis of autosomal recessive AS. CONCLUSIONS Our report suggests that in patients with clinical evidence of AS, genetic testing should be performed whenever pathological analysis is not in favor of AS diagnosis. This will ensure that AS patients benefit from an early diagnosis, adequate treatment, and that end-stage renal disease (ESRD) onset is delayed.
Collapse
Affiliation(s)
- Jeanne Truong
- Pediatric Nephrology Department, Robert Debré Hospital, 48 boulevard Sérurier, 75019, Paris, France.
| | - Georges Deschênes
- Pediatric Nephrology Department, Robert Debré Hospital, 48 boulevard Sérurier, 75019, Paris, France
| | - Patrice Callard
- Pathology Department, Tenon Hospital, 4 rue de la Chine, 75020, Paris, France
| | - Corinne Antignac
- Molecular Bases of Kidney Development, Inserm U1163 - Sorbonne Paris Cité - Paris Descartes University, 24 boulevard du Montparnasse, 75015, Paris, France
| | - Olivier Niel
- Pediatric Nephrology Department, Robert Debré Hospital, 48 boulevard Sérurier, 75019, Paris, France.,Molecular Bases of Kidney Development, Inserm U1163 - Sorbonne Paris Cité - Paris Descartes University, 24 boulevard du Montparnasse, 75015, Paris, France
| |
Collapse
|
30
|
Said SM, Fidler ME, Valeri AM, McCann B, Fiedler W, Cornell LD, Alexander MP, Alkhunaizi AM, Sullivan A, Cramer CH, Hogan MC, Nasr SH. Negative Staining for COL4A5 Correlates With Worse Prognosis and More Severe Ultrastructural Alterations in Males With Alport Syndrome. Kidney Int Rep 2016; 2:44-52. [PMID: 29142939 PMCID: PMC5678677 DOI: 10.1016/j.ekir.2016.09.056] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2016] [Accepted: 09/23/2016] [Indexed: 01/15/2023] Open
Abstract
Introduction Alport syndrome (AS) is a genetic disorder characterized by progressive hematuric nephropathy with or without sensorineural hearing loss and ocular lesions. Previous studies on AS included mostly children. Methods To determine the prognostic value of loss of staining for collagen type IV alpha 5 (COL4A5) and its relationship with the ultrastructural glomerular basement membrane alterations, we performed direct immunofluorescence using a mixture of fluorescein isothiocyanate-conjugated and Texas-red conjugated antibodies against COL4A5 and COL4A2, respectively, on renal biopsies of 25 males with AS (including 16 who were diagnosed in adulthood). Results All patients showed normal positive staining of glomerular basement membranes and tubular basement membranes for COL4A2. Of the 25 patients, 10 (40%) patients showed loss of staining for COL4A5 (including 89% of children and 13% of adults) and the remaining 15 (60%) had intact staining for COL4A5. Compared with patients with intact staining for COL4A5, those with loss of staining had more prominent ultrastructural glomerular basement membrane alterations and were younger at the time of biopsy. By Kaplan-Meier survival analysis and Cox regression analysis, loss of staining for COL4A5 predicted earlier progression to overt proteinuria and stage 2 chronic kidney disease or worse. By multivariate Cox regression analysis, loss of staining for COL4A5 was an independent predictor of the development of overt proteinuria and stage 2 chronic kidney disease or worse. Discussion Thus, the COL4A5 expression pattern has an important prognostic value and it correlates with the severity of ultrastructural glomerular basement membrane alterations in males with AS. Loss of COL4A5 staining is uncommon in patients with AS diagnosed in their adulthood.
Collapse
Affiliation(s)
- Samar M. Said
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
| | - Mary E. Fidler
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
| | - Anthony M. Valeri
- Division of Nephrology, Columbia University, College of Physicians and Surgeons, New York, New York, USA
| | - Brooke McCann
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
| | - Wade Fiedler
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
| | - Lynn D. Cornell
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
| | | | | | | | - Carl H. Cramer
- Division of Pediatric Nephrology, Mayo Clinic, Rochester, Minnesota, USA
| | - Marie C. Hogan
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA
| | - Samih H. Nasr
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
- Correspondence: Samih H. Nasr, Division of Anatomic Pathology, Mayo Clinic, Hilton 10-20, 200 First Street, SW, Rochester, Minnesota 55905, USA.Division of Anatomic PathologyMayo ClinicHilton 10-20, 200 First Street, SWRochesterMinnesota 55905USA
| |
Collapse
|
31
|
Nyström A, Bornert O, Kühl T. Cell therapy for basement membrane-linked diseases. Matrix Biol 2016; 57-58:124-139. [PMID: 27609402 DOI: 10.1016/j.matbio.2016.07.012] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 06/02/2016] [Accepted: 07/07/2016] [Indexed: 12/14/2022]
Abstract
For most disorders caused by mutations in genes encoding basement membrane (BM) proteins, there are at present only limited treatment options available. Genetic BM-linked disorders can be viewed as especially suited for treatment with cell-based therapy approaches because the proteins that need to be restored are located in the extracellular space. In consequence, complete and permanent engraftment of cells does not necessarily have to occur to achieve substantial causal therapeutic effects. For these disorders cells can be used as transient vehicles for protein replacement. In addition, it is becoming evident that BM-linked genetic disorders are modified by secondary diseases mechanisms. Cell-based therapies have also the ability to target such disease modifying mechanisms. Thus, cell therapies can simultaneously provide causal treatment and symptomatic relief, and accordingly hold great potential for treatment of BM-linked disorders. However, this potential has for most applications and diseases so far not been realized. Here, we will present the state of cell therapies for BM-linked diseases. We will discuss use of both pluripotent and differentiated cells, the limitation of the approaches, their challenges, and the way forward to potential wider implementation of cell therapies in the clinics.
Collapse
Affiliation(s)
- Alexander Nyström
- Department of Dermatology, Medical Center - University of Freiburg, Freiburg, Germany.
| | - Olivier Bornert
- Department of Dermatology, Medical Center - University of Freiburg, Freiburg, Germany
| | - Tobias Kühl
- Department of Dermatology, Medical Center - University of Freiburg, Freiburg, Germany
| |
Collapse
|
32
|
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.
Collapse
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.
| |
Collapse
|
33
|
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.
Collapse
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)
| |
Collapse
|
34
|
Rosado C, Bueno E, Felipe C, González-Sarmiento R. COL4A4 gene study of a European population: description of new mutations causing autosomal dominant Alport syndrome. INTERNATIONAL JOURNAL OF MOLECULAR EPIDEMIOLOGY AND GENETICS 2014; 5:177-184. [PMID: 25755845 PMCID: PMC4348702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Accepted: 11/28/2014] [Indexed: 06/04/2023]
Abstract
BACKGROUND Autosomal forms of Alport syndrome represent 20% of all patients (15% recessive and 5% dominant). They are caused by mutations in the COL4A3 and COL4A4 genes, which encode a-3 and a-4 collagen IV chains of the glomerular basement membrane, cochlea and eye. Thin basement membrane nephropathy may affect up to 1% of the population. The pattern of inheritance in the 40% of cases is the same as autosomal dominant Alport syndrome: heterozygous mutations in these genes. The aim of this study is to detect new pathogenic mutations in the COL4A4 gene in the patients previously diagnosed with autosomal Alport syndrome and thin basement membrane nephropathy in our hospital. METHODS We conducted a clinical and genetic study in eleven patients belonging to six unrelated families with aforementioned clinical symptoms and a negative study of COL4A3 gene. The molecular study was made by conformation of sensitive gel electrophoresis (CSGE) and direct sequencing of the fragments that show an altered electrophoretic migration pattern. RESULTS We found two pathogenic mutations, not yet described: IVS3 + 1G > C is a replacement of Guanine to Cytosine in position +1 of intron 3, in the splicing region, which leads to a pathogenic mutation. c.4267C > T; p.P1423S is a missense mutation, also considered pathogenic. We also found seven new polymorphisms. CONCLUSIONS We describe two new pathogenic mutations, responsible for autosomal dominant Alport syndrome. The other families of the study were undiagnosed owing to problems in the method employed and the possibility of mutations in other genes, giving rise to other diseases with similar symptoms.
Collapse
Affiliation(s)
- Consolación Rosado
- Department of Medicine, Molecular Medicine Unit, University of SalamancaSalamanca, Spain
- Department of Nephrology, Ávila HospitalÁvila, Spain
| | - Elena Bueno
- Department of Medicine, Molecular Medicine Unit, University of SalamancaSalamanca, Spain
- IBSAL and IBMCC, University of Salamanca, CSIC and SACYLSalamanca, Spain
| | - Carmen Felipe
- Department of Nephrology, Ávila HospitalÁvila, Spain
| | - Rogelio González-Sarmiento
- Department of Medicine, Molecular Medicine Unit, University of SalamancaSalamanca, Spain
- IBSAL and IBMCC, University of Salamanca, CSIC and SACYLSalamanca, Spain
| |
Collapse
|