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Salehi O, Mack H, Colville D, Lewis D, Savige J. Ocular manifestations of renal ciliopathies. Pediatr Nephrol 2024; 39:1327-1346. [PMID: 37644229 PMCID: PMC10942941 DOI: 10.1007/s00467-023-06096-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Revised: 07/09/2023] [Accepted: 07/10/2023] [Indexed: 08/31/2023]
Abstract
Renal ciliopathies are a common cause of kidney failure in children and adults, and this study reviewed their ocular associations. Genes affected in renal ciliopathies were identified from the Genomics England Panels. Ocular associations were identified from Medline and OMIM, and the genes additionally examined for expression in the human retina ( https://www.proteinatlas.org/humanproteome/tissue ) and for an ocular phenotype in mouse models ( http://www.informatics.jax.org/ ). Eighty-two of the 86 pediatric-onset renal ciliopathies (95%) have an ocular phenotype, including inherited retinal degeneration, oculomotor disorders, and coloboma. Diseases associated with pathogenic variants in ANK6, MAPKBP1, NEK8, and TCTN1 have no reported ocular manifestations, as well as low retinal expression and no ocular features in mouse models. Ocular abnormalities are not associated with the most common adult-onset "cystic" kidney diseases, namely, autosomal dominant (AD) polycystic kidney disease and the AD tubulointerstitial kidney diseases (ADTKD). However, other kidney syndromes with cysts have ocular features including papillorenal syndrome (optic disc dysplasia), Hereditary Angiopathy Nephropathy, Aneurysms and muscle Cramps (HANAC) (tortuous retinal vessels), tuberous sclerosis (retinal hamartomas), von Hippel-Lindau syndrome (retinal hemangiomas), and Alport syndrome (lenticonus, fleck retinopathy). Ocular abnormalities are associated with many pediatric-onset renal ciliopathies but are uncommon in adult-onset cystic kidney disease. However the demonstration of ocular manifestations may be helpful diagnostically and the features may require monitoring or treatment.
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Affiliation(s)
- Omar Salehi
- Department of Medicine (Melbourne Health and Northern Health), The University of Melbourne, Royal Melbourne Hospital, Parkville, VIC, 3050, Australia
| | - Heather Mack
- University Department of Surgery (Ophthalmology), Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, 3002, Australia
| | - Deb Colville
- University Department of Surgery (Ophthalmology), Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, 3002, Australia
| | - Debbie Lewis
- Nephrology Department, The Children's Hospital at Westmead, Westmead, NSW, 2145, Australia
| | - Judy Savige
- Department of Medicine (Melbourne Health and Northern Health), The University of Melbourne, Royal Melbourne Hospital, Parkville, VIC, 3050, Australia.
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2
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Zhu V, Huang T, Wang D, Colville D, Mack H, Savige J. Ocular manifestations of the genetic causes of focal and segmental glomerulosclerosis. Pediatr Nephrol 2024; 39:655-679. [PMID: 37578539 PMCID: PMC10817844 DOI: 10.1007/s00467-023-06073-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Revised: 06/11/2023] [Accepted: 06/19/2023] [Indexed: 08/15/2023]
Abstract
Genetic forms of focal and segmental glomerulosclerosis (FSGS) often have extra-renal manifestations. This study examined FSGS-associated genes from the Genomics England Renal proteinuria panel for reported and likely ocular features. Thirty-two of the 55 genes (58%) were associated with ocular abnormalities in human disease, and a further 12 (22%) were expressed in the retina or had an eye phenotype in mouse models. The commonest genes affected in congenital nephrotic syndrome (NPHS1, NPHS2, WT1, LAMB2, PAX2 but not PLCE1) may have ocular manifestations . Many genes affected in childhood-adolescent onset FSGS (NPHS1, NPHS2, WT1, LAMB2, SMARCAL1, NUP107 but not TRPC6 or PLCE1) have ocular features. The commonest genes affected in adult-onset FSGS (COL4A3-COL4A5, GLA ) have ocular abnormalities but not the other frequently affected genes (ACTN4, CD2AP, INF2, TRPC6). Common ocular associations of genetic FSGS include cataract, myopia, strabismus, ptosis and retinal atrophy. Mitochondrial forms of FSGS (MELAS, MIDD, Kearn's Sayre disease) are associated with retinal atrophy and inherited retinal degeneration. Some genetic kidney diseases (CAKUT, ciliopathies, tubulopathies) that result in secondary forms of FSGS also have ocular features. Ocular manifestations suggest a genetic basis for FSGS, often help identify the affected gene, and prompt genetic testing. In general, ocular abnormalities require early evaluation by an ophthalmologist, and sometimes, monitoring or treatment to improve vision or prevent visual loss from complications. In addition, the patient should be examined for other syndromic features and first degree family members assessed.
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Affiliation(s)
- Victor Zhu
- Department of Medicine (Melbourne Health and Northern Health), Royal Melbourne Hospital, The University of Melbourne, Parkville, VIC, 3050, Australia
| | - Tess Huang
- Department of Medicine (Melbourne Health and Northern Health), Royal Melbourne Hospital, The University of Melbourne, Parkville, VIC, 3050, Australia
| | - David Wang
- Department of Medicine (Melbourne Health and Northern Health), Royal Melbourne Hospital, The University of Melbourne, Parkville, VIC, 3050, Australia
| | - Deb Colville
- Department of Surgery, Royal Victorian Eye and Ear Hospital, The University of Melbourne, East Melbourne, VIC, 3002, Australia
| | - Heather Mack
- Department of Surgery, Royal Victorian Eye and Ear Hospital, The University of Melbourne, East Melbourne, VIC, 3002, Australia
| | - Judy Savige
- Department of Medicine (Melbourne Health and Northern Health), Royal Melbourne Hospital, The University of Melbourne, Parkville, VIC, 3050, Australia.
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3
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Gooley K, Williams P, Mack H, Zhu V, Langsford D, Pianta T, Barit D, Mahmood K, Savige J. A comparison of the ocular features in Pierson and Alport syndrome: a case report and literature review. Ophthalmic Genet 2023; 44:417-422. [PMID: 37537573 DOI: 10.1080/13816810.2023.2240881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 06/24/2023] [Accepted: 07/20/2023] [Indexed: 08/05/2023]
Abstract
BACKGROUND Pierson syndrome and X-linked Alport syndrome result from pathogenic variants in LAMB2 and COL4A5, respectively, and both affect basement membranes in the kidney and the eye. This study describes the ocular features in an individual with a homozygous LAMB2 pathogenic variant and compares the reported abnormalities in Pierson syndrome with those in Alport syndrome. METHODS A 28-year-old man who developed kidney failure 10 years previously and subsequently had an atrial septal defect repair was suspected of having genetic kidney disease on the basis of his likely diagnosis of Focal and Segmental Glomerulosclerosis (FSGS), his young age at presentation, and his cardiac anomaly. He then underwent Whole Exome Sequencing and a formal ophthalmological examination. RESULTS The patient was found to have a homozygous Likely Pathogenic missense variant (p.(Arg1719Cys)) in LAMB2 consistent with the diagnosis of Pierson syndrome. He had normal visual acuity, normal optic globe and cornea size, and normal lens appearance on direct examination. Upon further testing, his cornea demonstrated central thinning. There was also increased corneal endothelial pleomorphism, a reduced foveal reflex, and a blunted foveal curvature, similar to the features seen in X-linked Alport syndrome. CONCLUSION Our patient had a later onset form of Pierson syndrome or "FSGS type 5, with or without ocular abnormalities," consistent with his "milder" LAMB2 missense variant. The resemblance of the ocular features in Pierson syndrome and X-linked Alport syndrome suggests that mutations in LAMB2 and COL4A5 have similar effects on basement membranes and the pathogenesis of ocular damage.
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Affiliation(s)
- Kieran Gooley
- Department of Medicine (Melbourne Health and Northern Health), The University of Melbourne, Parkville, Australia
| | - Peter Williams
- Department of Medicine (Melbourne Health and Northern Health), The University of Melbourne, Parkville, Australia
| | - Heather Mack
- Department of Ophthalmology, The University of Melbourne, East Melbourne, Australia
| | - Victor Zhu
- Department of Medicine (Melbourne Health and Northern Health), The University of Melbourne, Parkville, Australia
| | | | - Tim Pianta
- Renal Unit, Northern Health, Epping, Australia
| | - David Barit
- Renal Unit, Northern Health, Epping, Australia
| | - Khalid Mahmood
- Melbourne Bioinformatics, The University of Melbourne, Parkville, Australia
| | - Judy Savige
- Department of Medicine (Melbourne Health and Northern Health), The University of Melbourne, Parkville, Australia
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Mizobuchi K, Hayashi T, Ohira R, Nakano T. Electroretinographic abnormalities in Alport syndrome with a novel COL4A5 truncated variant (p.Try20GlyfsTer19). Doc Ophthalmol 2023:10.1007/s10633-023-09935-w. [PMID: 37162688 DOI: 10.1007/s10633-023-09935-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 04/10/2023] [Indexed: 05/11/2023]
Abstract
PURPOSE Alport syndrome comprises a heterogeneous group of inherited kidney diseases that are associated with ocular complications. In this study, we aimed to detail the clinical characteristics of a patient with X-linked Alport syndrome. METHODS We performed next-generation sequencing (NGS) with hybridization capture to identify the disease-causing variant of Alport syndrome and a comprehensive ophthalmic examination, including full-field electroretinography (FF-ERG). RESULTS Genetic testing using NGS with hybridization capture revealed a novel hemizygous variant [c.51_52delGA (p.Trp20GlyfsTer19)] in exon 1 of COL4A5. The patient underwent cataract surgery in both eyes because of decreased visual acuity and photophobia. The best-corrected visual acuity improved from 0.9 and 0.7 in the right and left eyes, respectively, to 1.5 in both eyes. Anterior-segment optical coherence tomography (OCT) revealed anterior and posterior lenticonus. Fundus photographs showed central and peripheral fleck retinopathy. Wide-field fundus autofluorescence (AF) imaging showed mottled hyper- and hypo-AF in the peripheral retina, which was consistent with peripheral fleck retinopathy. Furthermore, OCT revealed thinning of the inner retinal layers, especially at the temporal macular, but the outer retinal layers were preserved. Ganglion cell analysis showed no progression for 5 years. FF-ERG was performed at 41 (phakia) and 46 (pseudophakia) years of age. The amplitudes of dark-adapted (DA) and light-adapted (LA) responses showed selective b-wave abnormalities. The b/a-wave ratios of DA 3.0 were 1.22 and 1.16 in the right and left eyes, respectively. The amplitudes of DA 3.0 oscillatory potentials (OP) were reduced. Five years later, the amplitudes of DA and LA responses revealed no remarkable changes, except for an OP wave of DA 3.0, which was substantially reduced. CONCLUSIONS Our findings revealed electroretinographic abnormalities in a patient with Alport syndrome, which predominantly indicated impairment of the inner retina. Notably, little short-term progression was observed.
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Affiliation(s)
- Kei Mizobuchi
- Department of Ophthalmology, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-Ku, Tokyo, 105-8461, Japan.
| | - Takaaki Hayashi
- Department of Ophthalmology, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-Ku, Tokyo, 105-8461, Japan
- Department of Ophthalmology, Katsushika Medical Center, The Jikei University School of Medicine, Tokyo, Japan
| | - Ryo Ohira
- Department of Ophthalmology, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-Ku, Tokyo, 105-8461, Japan
| | - Tadashi Nakano
- Department of Ophthalmology, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-Ku, Tokyo, 105-8461, Japan
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5
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Horaček M, Martić TN, Šenjug P, Perica MŠ, Oroz M, Kuzmac S, Klarić D, Glavina Durdov M, Saraga M, Milošević D, Batinić D, Ćorić M, Paić F, Ljubanović DG. Clinical and histopathological characteristics of COL4A3 c.2881+1G>A variant causing Alport spectrum disorders in Croatian population. BIOMOLECULES AND BIOMEDICINE 2023; 23:89-100. [PMID: 35880347 PMCID: PMC9901899 DOI: 10.17305/bjbms.2022.7567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Accepted: 06/28/2022] [Indexed: 02/08/2023]
Abstract
Alport syndrome (AS) and thin basement membrane nephropathy (TBMN) are part of the spectrum of kidney disorders caused by pathogenic variants in α3, α4, or α5 chains of the collagen type IV, the major structural component of the glomerular basement membrane (GBM). Using targeted next-generation sequencing (NGS), 34 AS/TBMN patients (58.8% male) from 12 unrelated families were found positive for heterozygous c.2881+1G>A variant of the COL4A3gene, that is considered disease-causing. All patients were from the continental or island part of Croatia. Clinical, laboratory, and histopathological data collected from the medical records were analyzed and compared to understand the clinical course and prognosis of the affected patients. At the time of biopsy or first clinical evaluation, the mean age was 31 years (median: 35 years; range: 1 - 72 years). Hematuria was present in 33 patients (97.1%) and 19 (55.9%) patients had proteinuria. There were 6 (17.6%) patients with hearing loss, 4 (11.8%) with ocular lesions, and 11 (32.4%) with hypertension. Twenty-three (67.6%) patients had proteinuria at follow-up, and 5 (14.7%) patients with the median age of 48 years (range: 27-55) progressed to kidney failure, started dialysis, or underwent kidney transplantation. Of the 13 patients who underwent kidney biopsy, 4 (30.8%) developed focal segmental glomerulosclerosis (FSGS), and 8 (66.7%) showed lamellation of the GBM, including all patients with FSGS. It is essential to conduct a detailed analysis of each collagen type IV genetic variant to optimize the prognosis and therapeutic approach for affected patients.
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Affiliation(s)
- Matija Horaček
- Institute of Pathology, School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Tamara Nikuševa Martić
- Department of Medical Biology and Genetics, School of Medicine, University of Zagreb, Zagreb, Croatia,Correspondence to Tamara Nikuševa Martić:
| | - Petar Šenjug
- Department of Nephropatology and Electron Microscopy, Dubrava University Hospital, Zagreb, Croatia
| | | | - Maja Oroz
- Department of Gynecology and Obstetrics, Clinical Hospital “Sveti Duh”, Zagreb, Croatia
| | - Sania Kuzmac
- Clinical Department of Pathology and Cytology, University Hospital Centre Zagreb, Zagreb, Croatia
| | - Dragan Klarić
- Department of Nephrology, General Hospital Zadar, Zadar, Croatia
| | | | - Marijan Saraga
- Department of Pediatrics, University Hospital Split, Split, Croatia
| | - Danko Milošević
- Department of Pediatrics, University Hospital Centre Zagreb, Zagreb, Croatia
| | - Danica Batinić
- Pediatric ordination dr. Danica Batinić, Zagreb, Croatia
| | - Marijana Ćorić
- Institute of Pathology, School of Medicine, University of Zagreb, Zagreb, Croatia,Clinical Department of Pathology and Cytology, University Hospital Centre Zagreb, Zagreb, Croatia
| | - Frane Paić
- Department of Medical Biology and Genetics, School of Medicine, University of Zagreb, Zagreb, Croatia,Laboratory for Epigenetics and Molecular Medicine, School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Danica Galešić Ljubanović
- Institute of Pathology, School of Medicine, University of Zagreb, Zagreb, Croatia,Department of Nephropatology and Electron Microscopy, Dubrava University Hospital, Zagreb, Croatia
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6
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Gibson JT, de Gooyer M, Huang M, Savige J. A systematic review of pathogenic COL4A5 variants and proteinuria in women and girls with X-linked Alport syndrome. Kidney Int Rep 2022; 7:2454-2461. [DOI: 10.1016/j.ekir.2022.08.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 08/20/2022] [Accepted: 08/22/2022] [Indexed: 11/17/2022] Open
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7
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Cocchi E, Nestor JG, Gharavi AG. Clinical Genetic Screening in Adult Patients with Kidney Disease. Clin J Am Soc Nephrol 2020; 15:1497-1510. [PMID: 32646915 PMCID: PMC7536756 DOI: 10.2215/cjn.15141219] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Expanded accessibility of genetic sequencing technologies, such as chromosomal microarray and massively parallel sequencing approaches, is changing the management of hereditary kidney diseases. Genetic causes account for a substantial proportion of pediatric kidney disease cases, and with increased utilization of diagnostic genetic testing in nephrology, they are now also detected at appreciable frequencies in adult populations. Establishing a molecular diagnosis can have many potential benefits for patient care, such as guiding treatment, familial testing, and providing deeper insights on the molecular pathogenesis of kidney diseases. Today, with wider clinical use of genetic testing as part of the diagnostic evaluation, nephrologists have the challenging task of selecting the most suitable genetic test for each patient, and then applying the results into the appropriate clinical contexts. This review is intended to familiarize nephrologists with the various technical, logistical, and ethical considerations accompanying the increasing utilization of genetic testing in nephrology care.
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Affiliation(s)
- Enrico Cocchi
- Division of Nephrology and Center for Precision Medicine and Genomics, Department of Medicine, Columbia University, New York, New York
- Department of Pediatrics, Universita' degli Studi di Torino, Torino, Italy
| | - Jordan Gabriela Nestor
- Division of Nephrology and Center for Precision Medicine and Genomics, Department of Medicine, Columbia University, New York, New York
| | - Ali G Gharavi
- Division of Nephrology and Center for Precision Medicine and Genomics, Department of Medicine, Columbia University, New York, New York
- Insititute of Genomic Medicine, Columbia University, New York, New York
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8
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Nestor JG, Marasa M, Milo-Rasouly H, Groopman EE, Husain SA, Mohan S, Fernandez H, Aggarwal VS, Ahram DF, Vena N, Bogyo K, Bomback AS, Radhakrishnan J, Appel GB, Ahn W, Cohen DJ, Canetta PA, Dube GK, Rao MK, Morris HK, Crew RJ, Sanna-Cherchi S, Kiryluk K, Gharavi AG. Pilot Study of Return of Genetic Results to Patients in Adult Nephrology. Clin J Am Soc Nephrol 2020; 15:651-664. [PMID: 32299846 PMCID: PMC7269209 DOI: 10.2215/cjn.12481019] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 03/12/2020] [Indexed: 12/18/2022]
Abstract
BACKGROUND AND OBJECTIVES Actionable genetic findings have implications for care of patients with kidney disease, and genetic testing is an emerging tool in nephrology practice. However, there are scarce data regarding best practices for return of results and clinical application of actionable genetic findings for kidney patients. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS We developed a return of results workflow in collaborations with clinicians for the retrospective recontact of adult nephrology patients who had been recruited into a biobank research study for exome sequencing and were identified to have medically actionable genetic findings. RESULTS Using this workflow, we attempted to recontact a diverse pilot cohort of 104 nephrology research participants with actionable genetic findings, encompassing 34 different monogenic etiologies of nephropathy and five single-gene disorders recommended by the American College of Medical Genetics and Genomics for return as medically actionable secondary findings. We successfully recontacted 64 (62%) participants and returned results to 41 (39%) individuals. In each case, the genetic diagnosis had meaningful implications for the patients' nephrology care. Through implementation efforts and qualitative interviews with providers, we identified over 20 key challenges associated with returning results to study participants, and found that physician knowledge gaps in genomics was a recurrent theme. We iteratively addressed these challenges to yield an optimized workflow, which included standardized consultation notes with tailored management recommendations, monthly educational conferences on core topics in genomics, and a curated list of expert clinicians for patients requiring extranephrologic referrals. CONCLUSIONS Developing the infrastructure to support return of genetic results in nephrology was resource-intensive, but presented potential opportunities for improving patient care. PODCAST This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2020_04_16_12481019.mp3.
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Affiliation(s)
- Jordan G Nestor
- Division of Nephrology, Department of Medicine, Columbia University, New York, New York
| | - Maddalena Marasa
- Division of Nephrology, Department of Medicine, Columbia University, New York, New York
| | - Hila Milo-Rasouly
- Division of Nephrology, Department of Medicine, Columbia University, New York, New York
| | - Emily E Groopman
- Division of Nephrology, Department of Medicine, Columbia University, New York, New York
| | - S Ali Husain
- Division of Nephrology, Department of Medicine, Columbia University, New York, New York
| | - Sumit Mohan
- Division of Nephrology, Department of Medicine, Columbia University, New York, New York.,Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, New York
| | - Hilda Fernandez
- Division of Nephrology, Department of Medicine, Columbia University, New York, New York
| | - Vimla S Aggarwal
- Department of Pathology and Cell Biology, Columbia University, New York, New York
| | - Dina F Ahram
- Division of Nephrology, Department of Medicine, Columbia University, New York, New York
| | - Natalie Vena
- Division of Nephrology, Department of Medicine, Columbia University, New York, New York.,Institute for Genomic Medicine, Columbia University, New York, New York
| | - Kelsie Bogyo
- Division of Nephrology, Department of Medicine, Columbia University, New York, New York.,Department of Pathology and Cell Biology, Columbia University, New York, New York
| | - Andrew S Bomback
- Division of Nephrology, Department of Medicine, Columbia University, New York, New York
| | - Jai Radhakrishnan
- Division of Nephrology, Department of Medicine, Columbia University, New York, New York
| | - Gerald B Appel
- Division of Nephrology, Department of Medicine, Columbia University, New York, New York
| | - Wooin Ahn
- Division of Nephrology, Department of Medicine, Columbia University, New York, New York
| | - David J Cohen
- Division of Nephrology, Department of Medicine, Columbia University, New York, New York
| | - Pietro A Canetta
- Division of Nephrology, Department of Medicine, Columbia University, New York, New York
| | - Geoffrey K Dube
- Division of Nephrology, Department of Medicine, Columbia University, New York, New York
| | - Maya K Rao
- Division of Nephrology, Department of Medicine, Columbia University, New York, New York
| | - Heather K Morris
- Division of Nephrology, Department of Medicine, Columbia University, New York, New York
| | - Russell J Crew
- Division of Nephrology, Department of Medicine, Columbia University, New York, New York
| | - Simone Sanna-Cherchi
- Division of Nephrology, Department of Medicine, Columbia University, New York, New York
| | - Krzysztof Kiryluk
- Division of Nephrology, Department of Medicine, Columbia University, New York, New York
| | - Ali G Gharavi
- Division of Nephrology, Department of Medicine, Columbia University, New York, New York .,Institute for Genomic Medicine, Columbia University, New York, New York
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9
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Savige J, Ariani F, Mari F, Bruttini M, Renieri A, Gross O, Deltas C, Flinter F, Ding J, Gale DP, Nagel M, Yau M, Shagam L, Torra R, Ars E, Hoefele J, Garosi G, Storey H. Expert consensus guidelines for the genetic diagnosis of Alport syndrome. Pediatr Nephrol 2019; 34:1175-1189. [PMID: 29987460 DOI: 10.1007/s00467-018-3985-4] [Citation(s) in RCA: 76] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 02/22/2018] [Accepted: 05/10/2018] [Indexed: 12/16/2022]
Abstract
Recent expert guidelines recommend genetic testing for the diagnosis of Alport syndrome. Here, we describe current best practice and likely future developments. In individuals with suspected Alport syndrome, all three COL4A5, COL4A3 and COL4A4 genes should be examined for pathogenic variants, probably by high throughput-targeted next generation sequencing (NGS) technologies, with a customised panel for simultaneous testing of the three Alport genes. These techniques identify up to 95% of pathogenic COL4A variants. Where causative pathogenic variants cannot be demonstrated, the DNA should be examined for deletions or insertions by re-examining the NGS sequencing data or with multiplex ligation-dependent probe amplification (MLPA). These techniques identify a further 5% of variants, and the remaining few changes include deep intronic splicing variants or cases of somatic mosaicism. Where no pathogenic variants are found, the basis for the clinical diagnosis should be reviewed. Genes in which mutations produce similar clinical features to Alport syndrome (resulting in focal and segmental glomerulosclerosis, complement pathway disorders, MYH9-related disorders, etc.) should be examined. NGS approaches have identified novel combinations of pathogenic variants in Alport syndrome. Two variants, with one in COL4A3 and another in COL4A4, produce a more severe phenotype than an uncomplicated heterozygous change. NGS may also identify further coincidental pathogenic variants in genes for podocyte-expressed proteins that also modify the phenotype. Our understanding of the genetics of Alport syndrome is evolving rapidly, and both genetic and non-genetic factors are likely to contribute to the observed phenotypic variability.
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Affiliation(s)
- Judy Savige
- Department of Medicine, Melbourne and Northern Health, The University of Melbourne, Parkville, VIC, 3050, Australia.
| | | | | | | | | | - Oliver Gross
- Clinic of Nephrology and Rheumatology, University of Gottingen, Gottingen, Germany
| | | | - Frances Flinter
- Department of Clinical Genetics, Guys' and St Thomas' NHS Foundation Trust, London, UK
| | - Jie Ding
- Peking University First Hospital, Beijing, China
| | - Daniel P Gale
- Centre for Nephrology, Royal Free Hospital, University College London, London, UK
| | - Mato Nagel
- Centre for Nephrology and Metabolic Disorders, Weisswasser, Germany
| | - Michael Yau
- Genetics, Guy's Hospital, Viapath, London, UK
| | - Lev Shagam
- Institute of Pediatrics, Pirogov Russian Medical University, Moscow, Russia
| | - Roser Torra
- Inherited Kidney Disorders, Nephrology Department, Fundacio Puigvert, Instituto de Investigacion Carlos III, Universitat Autonoma de Barcelona, Barcelona, Spain
| | - Elisabet Ars
- Molecular Biology Laboratory, Fundacio Puigvert, Instituto de Investigacion Carlos III, Universitat Autonoma de Barcelona, Barcelona, Spain
| | - Julia Hoefele
- Institute of Human Genetics, Technical University Munich, Munich, Germany
| | - Guido Garosi
- Nephrology, Dialysis and Transplantation, Azienda Ospedaliera Universitaria Senese, Siena, Italy
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10
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Li Y, He Q, Wang Y, Wang Y, Dang X, Wu X, Li X, Shuai L, Yi Z. Novel deletion mutation in a Chinese family with X-linked alport syndrome. INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY 2018; 11:4657-4665. [PMID: 31949866 PMCID: PMC6962970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 06/23/2018] [Indexed: 06/10/2023]
Abstract
BACKGROUNDS AND OBJECTIVES alport syndrome (AS) is a progressive hereditary condition that is characterized by haematuria, proteinuria, progressive renal impairment, and end stage kidney disease (ESRD). Approximately 85% of AS patients have X-linked mutations in the COL4A5 gene that encodes type IV collagen. The aim of our study was to identify the gene responsible for glomerulopathy in a 3-generation Chinese pedigree with familial haematuria. METHODS We examined five members of a Chinese family clinically suspected of X-linked AS caused by COL4A5 gene mutations. All 51 exons of the COL4A5 gene were screened by direct DNA sequencing. RESULTS We identified the novel deletion mutation c. 3990_4016delCCC…TCC in COL4A5 in three affected individuals with haematuria, but the mutation was absent in the other 2 healthy family members and 100 unrelated healthy controls. CONCLUSIONS Our result demonstrates that the mutation is pathogenic and novel and has meaningful implications for the diagnosis and genetic counselling of cases with AS. The results in the study broaden the genotypic spectrum of known mutations for AS.
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Affiliation(s)
- Yongzhen Li
- Department of Pediatrics, The Second Xiangya Hospital, Central South UniversityChangsha, Hunan, P. R. China
- Laboratory of Pediatric Nephrology, Institute of Pediatrics, Central South UniversityChangsha, Hunan, P. R. China
| | - Qingnan He
- Department of Pediatrics, The Second Xiangya Hospital, Central South UniversityChangsha, Hunan, P. R. China
- Laboratory of Pediatric Nephrology, Institute of Pediatrics, Central South UniversityChangsha, Hunan, P. R. China
| | - Yanran Wang
- Department of Pediatrics, The Second Xiangya Hospital, Central South UniversityChangsha, Hunan, P. R. China
- Laboratory of Pediatric Nephrology, Institute of Pediatrics, Central South UniversityChangsha, Hunan, P. R. China
| | - Ying Wang
- Department of Pediatrics, The Second Xiangya Hospital, Central South UniversityChangsha, Hunan, P. R. China
- Laboratory of Pediatric Nephrology, Institute of Pediatrics, Central South UniversityChangsha, Hunan, P. R. China
| | - Xiqiang Dang
- Department of Pediatrics, The Second Xiangya Hospital, Central South UniversityChangsha, Hunan, P. R. China
- Laboratory of Pediatric Nephrology, Institute of Pediatrics, Central South UniversityChangsha, Hunan, P. R. China
| | - Xiaochuan Wu
- Department of Pediatrics, The Second Xiangya Hospital, Central South UniversityChangsha, Hunan, P. R. China
- Laboratory of Pediatric Nephrology, Institute of Pediatrics, Central South UniversityChangsha, Hunan, P. R. China
| | - Xiaoyan Li
- Department of Pediatrics, The Second Xiangya Hospital, Central South UniversityChangsha, Hunan, P. R. China
- Laboratory of Pediatric Nephrology, Institute of Pediatrics, Central South UniversityChangsha, Hunan, P. R. China
| | - Lanjun Shuai
- Department of Pediatrics, The Second Xiangya Hospital, Central South UniversityChangsha, Hunan, P. R. China
- Laboratory of Pediatric Nephrology, Institute of Pediatrics, Central South UniversityChangsha, Hunan, P. R. China
| | - Zhuwen Yi
- Department of Pediatrics, The Second Xiangya Hospital, Central South UniversityChangsha, Hunan, P. R. China
- Laboratory of Pediatric Nephrology, Institute of Pediatrics, Central South UniversityChangsha, Hunan, P. R. China
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11
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Hu P, Hunt NH, Arfuso F, Shaw LC, Uddin MN, Zhu M, Devasahayam R, Adamson SJ, Benson VL, Chan-Ling T, Grant MB. Increased Indoleamine 2,3-Dioxygenase and Quinolinic Acid Expression in Microglia and Müller Cells of Diabetic Human and Rodent Retina. Invest Ophthalmol Vis Sci 2017; 58:5043-5055. [PMID: 28980000 PMCID: PMC5633007 DOI: 10.1167/iovs.17-21654] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Purpose We investigated the relationship between inflammation, neuronal loss, and expression of indoleamine 2, 3-dioxygenase (IDO) and quinolinic acid (QUIN) in the retina of subjects with type 1 diabetes (T1D) and type 2 diabetes (T2D) and in the retina of rats with T1D. Methods Retinas from T1D (n = 7), T2D (n = 13), and 20 age-matched nondiabetic human donors and from T1D (n = 3) and control rats (n = 3) were examined using immunohistochemistry for IDO, QUIN, cluster of differentiation 39 (CD39), ionized calcium-binding adaptor molecule (Iba-1, for macrophages and microglia), Vimentin (VIM; for Müller cells), neuronal nuclei (NeuN; for neurons), and UEA1 lectin (for blood vessels). Results Based on morphologic criteria, CD39+/ionized calcium binding adaptor molecule 1(Iba-1+) resident microglia and CD39−/Iba-1+ bone marrow–derived macrophages were present at higher density in T1D (13% increase) and T2D (26% increase) human retinas when compared with controls. The density and brightness of IDO+ microglia were increased in both T1D and T2D human retinas. The intensity of QUIN+ expression on CD39+ microglia and VIM+ Müller cells was greatly increased in both human T1D and T2D retinas. T1D retinas showed a 63% loss of NeuN+ neurons and T2D retinas lost approximately 43% when compared with nondiabetic human retinas. Few QUIN+ microglia-like cells were seen in nondiabetic retinas, but the numbers increased 18-fold in T1D and 7-fold in T2D in the central retina. In T1D rat retinas, the density of IDO+ microglia increased 2.8-fold and brightness increased 2.1-fold when compared with controls. Conclusions Our findings suggest that IDO and QUIN expression in the retinas of diabetic rats and humans could contribute to the neuronal degeneration that is characteristic of diabetic retinopathy.
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Affiliation(s)
- Ping Hu
- Department of Anatomy, Bosch Institute, University of Sydney, New South Wales, Australia.,Department of Ophthalmology, the Eugene and Marilyn Glick Eye Institute, Indiana University, Indianapolis, Indiana, United States
| | - Nicholas H Hunt
- Department of Pathology, Bosch Institute, University of Sydney, New South Wales, Australia
| | - Frank Arfuso
- Department of Anatomy, Bosch Institute, University of Sydney, New South Wales, Australia.,Stem Cell & Cancer Biology Laboratory, School of Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Perth, Australia
| | - Lynn C Shaw
- Department of Ophthalmology, the Eugene and Marilyn Glick Eye Institute, Indiana University, Indianapolis, Indiana, United States
| | - Mohammad Nasir Uddin
- Department of Anatomy, Bosch Institute, University of Sydney, New South Wales, Australia
| | - Meidong Zhu
- Lions New South Wales Eye Bank, New South Wales Organ and Tissue Donation Service, South Eastern Sydney Local Health District, New South Wales, Australia.,Save Sight Institute, Discipline of Clinical Ophthalmology and Eye Health, University of Sydney, New South Wales, Australia
| | - Raj Devasahayam
- Lions New South Wales Eye Bank, New South Wales Organ and Tissue Donation Service, South Eastern Sydney Local Health District, New South Wales, Australia
| | - Samuel J Adamson
- Department of Anatomy, Bosch Institute, University of Sydney, New South Wales, Australia
| | - Vicky L Benson
- Department of Physiology, Faculty of Health and Medical Sciences, University of Auckland, Auckland, New Zealand
| | - Tailoi Chan-Ling
- Department of Anatomy, Bosch Institute, University of Sydney, New South Wales, Australia
| | - Maria B Grant
- Department of Ophthalmology, the Eugene and Marilyn Glick Eye Institute, Indiana University, Indianapolis, Indiana, United States.,Univeristy of Alabama, Birmingham, Alabama, United States
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12
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Syndrome d’Alport : néphropathie héréditaire associée à des mutations dans les gènes codant les chaînes de collagène de type IV. Nephrol Ther 2016; 12:544-551. [DOI: 10.1016/j.nephro.2016.09.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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13
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Savige J, Storey H, Il Cheong H, Gyung Kang H, Park E, Hilbert P, Persikov A, Torres-Fernandez C, Ars E, Torra R, Hertz JM, Thomassen M, Shagam L, Wang D, Wang Y, Flinter F, Nagel M. X-Linked and Autosomal Recessive Alport Syndrome: Pathogenic Variant Features and Further Genotype-Phenotype Correlations. PLoS One 2016; 11:e0161802. [PMID: 27627812 PMCID: PMC5023110 DOI: 10.1371/journal.pone.0161802] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 08/14/2016] [Indexed: 01/15/2023] Open
Abstract
Alport syndrome results from mutations in the COL4A5 (X-linked) or COL4A3/COL4A4 (recessive) genes. This study examined 754 previously- unpublished variants in these genes from individuals referred for genetic testing in 12 accredited diagnostic laboratories worldwide, in addition to all published COL4A5, COL4A3 and COL4A4 variants in the LOVD databases. It also determined genotype-phenotype correlations for variants where clinical data were available. Individuals were referred for genetic testing where Alport syndrome was suspected clinically or on biopsy (renal failure, hearing loss, retinopathy, lamellated glomerular basement membrane), variant pathogenicity was assessed using currently-accepted criteria, and variants were examined for gene location, and age at renal failure onset. Results were compared using Fisher’s exact test (DNA Stata). Altogether 754 new DNA variants were identified, an increase of 25%, predominantly in people of European background. Of the 1168 COL4A5 variants, 504 (43%) were missense mutations, 273 (23%) splicing variants, 73 (6%) nonsense mutations, 169 (14%) short deletions and 76 (7%) complex or large deletions. Only 135 of the 432 Gly residues in the collagenous sequence were substituted (31%), which means that fewer than 10% of all possible variants have been identified. Both missense and nonsense mutations in COL4A5 were not randomly distributed but more common at the 70 CpG sequences (p<10−41 and p<0.001 respectively). Gly>Ala substitutions were underrepresented in all three genes (p< 0.0001) probably because of an association with a milder phenotype. The average age at end-stage renal failure was the same for all mutations in COL4A5 (24.4 ±7.8 years), COL4A3 (23.3 ± 9.3) and COL4A4 (25.4 ± 10.3) (COL4A5 and COL4A3, p = 0.45; COL4A5 and COL4A4, p = 0.55; COL4A3 and COL4A4, p = 0.41). For COL4A5, renal failure occurred sooner with non-missense than missense variants (p<0.01). For the COL4A3 and COL4A4 genes, age at renal failure occurred sooner with two non-missense variants (p = 0.08, and p = 0.01 respectively). Thus DNA variant characteristics that predict age at renal failure appeared to be the same for all three Alport genes. Founder mutations (with the pathogenic variant in at least 5 apparently- unrelated individuals) were not necessarily associated with a milder phenotype. This study illustrates the benefits when routine diagnostic laboratories share and analyse their data.
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Affiliation(s)
- Judith Savige
- The University of Melbourne, Melbourne Health and Northern Health, Melbourne, Australia
- * E-mail:
| | - Helen Storey
- Molecular Genetics Laboratory, Guy’s and St Thomas’ Hospital, London, United Kingdom
| | - Hae Il Cheong
- Research Coordination Center for Rare Diseases, Seoul National University Hospital, Seoul, Korea
| | - Hee Gyung Kang
- Research Coordination Center for Rare Diseases, Seoul National University Hospital, Seoul, Korea
| | - Eujin Park
- Research Coordination Center for Rare Diseases, Seoul National University Hospital, Seoul, Korea
| | - Pascale Hilbert
- Institut de Pathologie et Genetique, Department of Molecular Biology, Gosselles, Belgium
| | - Anton Persikov
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, United States of America
| | | | - Elisabet Ars
- Molecular Biology Laboratory and Department of Nephrology, REDINREN, Fundacio Puigvert, Universitat Autonoma de Barcelona, Barcelona, Spain
| | - Roser Torra
- Molecular Biology Laboratory and Department of Nephrology, REDINREN, Fundacio Puigvert, Universitat Autonoma de Barcelona, Barcelona, Spain
| | - Jens Michael Hertz
- Department of Clinical Genetics, Odense University Hospital, Odense, Denmark
| | - Mads Thomassen
- Department of Clinical Genetics, Odense University Hospital, Odense, Denmark
| | - Lev Shagam
- Institute of Pediatrics, Pirogov Russian Medical University, Moscow, Russia
| | - Dongmao Wang
- The University of Melbourne, Melbourne Health and Northern Health, Melbourne, Australia
| | - Yanyan Wang
- The University of Melbourne, Melbourne Health and Northern Health, Melbourne, Australia
| | - Frances Flinter
- Department of Genetics, Guy’s and St Thomas’ Hospital, London, United Kingdom
| | - Mato Nagel
- Centre for Nephrology and Metabolic Medicine, Weisswasser D-02943, Germany
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14
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Savige J, Wang Y, Crawford A, Smith J, Symons A, Mack H, Nicholls K, Wilson D, Colville D. Bull's eye and pigment maculopathy are further retinal manifestations of an abnormal Bruch's membrane in Alport syndrome. Ophthalmic Genet 2016; 38:238-244. [PMID: 27485810 DOI: 10.1080/13816810.2016.1210648] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
BACKGROUND AND OBJECTIVES The retinal features of Alport syndrome include a central and peripheral fleck retinopathy, temporal retinal thinning, and a macular hole. Here we describe further retinal abnormalities. METHODS We identified a case of bull's eye maculopathy 20 years previously in a 68-year-old female, and reviewed archived retinal images from our cohort of X-linked (28 males, 28 females) or autosomal recessive (n = 13) Alport syndrome. All individuals had Alport syndrome confirmed on genetic testing or renal biopsy, were examined by an ophthalmologist, and underwent retinal imaging (KOWA non-mydriatic camera, Japan). RESULTS The index case had the p.Q379X variant in COL4A5 and currently had renal impairment, (eGFR = 45 ml/min/1.73 m2), bilateral hearing loss, and central and peripheral retinopathies. Her maculopathy had deteriorated, and she had a bilateral central visual field loss. Optical coherence tomography (Heidelberg Spectralis) demonstrated a disrupted retinal pigment epithelium and retinal atrophy. We identified a further early bull's eye maculopathy (1/69, 1.4%) from a female with autosomal recessive disease and normal renal function. We also noted a subtle pigment maculopathy associated with an abnormal retinal pigment epithelium in 27 (27/69, 39%) subjects with Alport syndrome, in both males (8/28, 29%) and females (13/28, 46%) with X-linked disease, and in autosomal recessive disease (6/13, 38%). CONCLUSIONS The bull's eye and pigment maculopathies in Alport syndrome result mainly from the damaged Bruch's membrane and overlying retinal pigment epithelium. Bull's eye maculopathy affects vision and patients should undergo regular monitoring for retinal complications.
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Affiliation(s)
- Judy Savige
- a Department of Medicine , Royal Melbourne Hospital, The University of Melbourne , Parkville , Victoria , Australia.,b Northern Health , Epping , Victoria , Australia.,c Department of Nephrology , Royal Melbourne Hospital , Parkville , Victoria , Australia
| | - Yanyan Wang
- a Department of Medicine , Royal Melbourne Hospital, The University of Melbourne , Parkville , Victoria , Australia.,b Northern Health , Epping , Victoria , Australia
| | - Andrew Crawford
- a Department of Medicine , Royal Melbourne Hospital, The University of Melbourne , Parkville , Victoria , Australia.,b Northern Health , Epping , Victoria , Australia
| | - James Smith
- a Department of Medicine , Royal Melbourne Hospital, The University of Melbourne , Parkville , Victoria , Australia.,b Northern Health , Epping , Victoria , Australia
| | - Andrew Symons
- c Department of Nephrology , Royal Melbourne Hospital , Parkville , Victoria , Australia.,d Eye Surgery Associates , East Melbourne , Victoria , Australia
| | - Heather Mack
- d Eye Surgery Associates , East Melbourne , Victoria , Australia
| | - Kathy Nicholls
- e Department of Ophthalmology , Royal Melbourne Hospital , Parkville , Victoria , Australia
| | - Diane Wilson
- a Department of Medicine , Royal Melbourne Hospital, The University of Melbourne , Parkville , Victoria , Australia.,b Northern Health , Epping , Victoria , Australia
| | - Deb Colville
- a Department of Medicine , Royal Melbourne Hospital, The University of Melbourne , Parkville , Victoria , Australia.,b Northern Health , Epping , Victoria , Australia
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15
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Fernandez-Rosado F, Campos A, Alvarez-Cubero MJ, Ruiz A, Entrala-Bernal C. Improved genetic counseling in Alport syndrome by new variants of COL4A5 gene. Nephrology (Carlton) 2016; 20:502-5. [PMID: 26063487 DOI: 10.1111/nep.12486] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
There are current requirements of using genetic databases for offering a better genetic assistance to patients of some syndromes, especially those with X-linked heredity patterns (like Alport Syndrome) for the high probability of having descendants affected by the disease. We describe the first reported case of COL4A5 gene missense c.1499 G>T mutation in a 16-year-old girl confirmed to be affected by Alport Syndrome after genetic counseling. Next Generation Sequencing procedures let discover this mutation and offer an accurate clinical treatment to this patient. Current scientific understanding of genetic syndromes suggests the high importance of updated databases and the inclusion of Variant of Unknown Significance related to clinical cases. All of this updating could enable patients to have a better opportunity of diagnosis and having genetic and clinical counseling. This event is even more important in women planning to start a family to have correct genetic counseling regarding the risk posed to offspring, and allowing the decision to undergo prenatal testing.
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Affiliation(s)
- Francisco Fernandez-Rosado
- LORGEN G.P, S.L., Business Innovation Center - BIC/CEEL, Technological area of Health Science, Granada, Spain
| | - Ana Campos
- Torrecardenas Hospital, Pediatry and Nephropediatric Service, Almeria, Spain
| | - Maria Jesus Alvarez-Cubero
- LORGEN G.P, S.L., Business Innovation Center - BIC/CEEL, Technological area of Health Science, Granada, Spain.,Genetic Identification Laboratory, Legal Medicine and Toxicology Department, Medicine Faculty, University of Granada, Granada, Spain.,GENYO (Pfizer-University of Granada-Andalusian Government Centre for Genomics and Oncological Research), Granada, Spain
| | - Ana Ruiz
- Torrecardenas Hospital, Pediatry and Nephropediatric Service, Almeria, Spain
| | - Carmen Entrala-Bernal
- LORGEN G.P, S.L., Business Innovation Center - BIC/CEEL, Technological area of Health Science, Granada, Spain
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17
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Savige J, Sheth S, Leys A, Nicholson A, Mack HG, Colville D. Ocular features in Alport syndrome: pathogenesis and clinical significance. Clin J Am Soc Nephrol 2015. [PMID: 25649157 DOI: 10.2215/cjn.10581014;pmid:25649157] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Alport syndrome is an inherited disease characterized by progressive renal failure, hearing loss, and ocular abnormalities. Mutations in the COL4A5 (X-linked), or COL4A3 and COL4A4 (autosomal recessive) genes result in absence of the collagen IV α3α4α5 network from the basement membranes of the cornea, lens capsule, and retina and are associated with corneal opacities, anterior lenticonus, fleck retinopathy, and temporal retinal thinning. Typically, these features do not affect vision or, in the case of lenticonus, are correctable. In contrast, the rarer ophthalmic complications of posterior polymorphous corneal dystrophy, giant macular hole, and maculopathy all produce visual loss. Many of the ocular features of Alport syndrome are common, easily recognizable, and thus, helpful diagnostically, and in identifying the likelihood of early-onset renal failure. Lenticonus and central fleck retinopathy strongly suggest the diagnosis of Alport syndrome and are associated with renal failure before the age of 30 years, in males with X-linked disease. Sometimes, ophthalmic features suggest the mode of inheritance. A peripheral retinopathy in the mother of a male with hematuria suggests X-linked inheritance, and central retinopathy or lenticonus in a female means that recessive disease is likely. Ocular examination, retinal photography, and optical coherence tomography are widely available, safe, fast, inexpensive, and acceptable to patients. Ocular examination is particularly helpful in the diagnosis of Alport syndrome when genetic testing is not readily available or the results are inconclusive. It also detects complications, such as macular hole, for which new treatments are emerging.
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Affiliation(s)
- Judy Savige
- Department of Medicine, The University of Melbourne, Royal Melbourne Hospital, Parkville, Victoria, Australia; The University of Melbourne Department of Medicine, Northern Health, Epping, Victoria, Australia; Department of Nephrology, Royal Melbourne Hospital, Parkville, Victoria, Australia;
| | - Shivanand Sheth
- Department of Ophthalmology, Royal Children's Hospital, Parkville, Victoria, Australia; Department of Ophthalmology, Bai Yamunabai Laxman Nair Charitable Hospital, Mumbai, India
| | - Anita Leys
- Department of Ophthalmology, Universitaire Ziekenhuizen, Leuven, Belgium; and
| | - Anjali Nicholson
- Department of Ophthalmology, Bai Yamunabai Laxman Nair Charitable Hospital, Mumbai, India
| | - Heather G Mack
- Department of Ophthalmology, The University of Melbourne, East Melbourne, Victoria, Australia
| | - Deb Colville
- Department of Medicine, The University of Melbourne, Royal Melbourne Hospital, Parkville, Victoria, Australia; Department of Ophthalmology, Royal Children's Hospital, Parkville, Victoria, Australia
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18
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Savige J, Sheth S, Leys A, Nicholson A, Mack HG, Colville D. Ocular features in Alport syndrome: pathogenesis and clinical significance. Clin J Am Soc Nephrol 2015; 10:703-9. [PMID: 25649157 DOI: 10.2215/cjn.10581014] [Citation(s) in RCA: 126] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Alport syndrome is an inherited disease characterized by progressive renal failure, hearing loss, and ocular abnormalities. Mutations in the COL4A5 (X-linked), or COL4A3 and COL4A4 (autosomal recessive) genes result in absence of the collagen IV α3α4α5 network from the basement membranes of the cornea, lens capsule, and retina and are associated with corneal opacities, anterior lenticonus, fleck retinopathy, and temporal retinal thinning. Typically, these features do not affect vision or, in the case of lenticonus, are correctable. In contrast, the rarer ophthalmic complications of posterior polymorphous corneal dystrophy, giant macular hole, and maculopathy all produce visual loss. Many of the ocular features of Alport syndrome are common, easily recognizable, and thus, helpful diagnostically, and in identifying the likelihood of early-onset renal failure. Lenticonus and central fleck retinopathy strongly suggest the diagnosis of Alport syndrome and are associated with renal failure before the age of 30 years, in males with X-linked disease. Sometimes, ophthalmic features suggest the mode of inheritance. A peripheral retinopathy in the mother of a male with hematuria suggests X-linked inheritance, and central retinopathy or lenticonus in a female means that recessive disease is likely. Ocular examination, retinal photography, and optical coherence tomography are widely available, safe, fast, inexpensive, and acceptable to patients. Ocular examination is particularly helpful in the diagnosis of Alport syndrome when genetic testing is not readily available or the results are inconclusive. It also detects complications, such as macular hole, for which new treatments are emerging.
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Affiliation(s)
- Judy Savige
- Department of Medicine, The University of Melbourne, Royal Melbourne Hospital, Parkville, Victoria, Australia; The University of Melbourne Department of Medicine, Northern Health, Epping, Victoria, Australia; Department of Nephrology, Royal Melbourne Hospital, Parkville, Victoria, Australia;
| | - Shivanand Sheth
- Department of Ophthalmology, Royal Children's Hospital, Parkville, Victoria, Australia; Department of Ophthalmology, Bai Yamunabai Laxman Nair Charitable Hospital, Mumbai, India
| | - Anita Leys
- Department of Ophthalmology, Universitaire Ziekenhuizen, Leuven, Belgium; and
| | - Anjali Nicholson
- Department of Ophthalmology, Bai Yamunabai Laxman Nair Charitable Hospital, Mumbai, India
| | - Heather G Mack
- Department of Ophthalmology, The University of Melbourne, East Melbourne, Victoria, Australia
| | - Deb Colville
- Department of Medicine, The University of Melbourne, Royal Melbourne Hospital, Parkville, Victoria, Australia; Department of Ophthalmology, Royal Children's Hospital, Parkville, Victoria, Australia
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Mencarelli MA, Heidet L, Storey H, van Geel M, Knebelmann B, Fallerini C, Miglietti N, Antonucci MF, Cetta F, Sayer JA, van den Wijngaard A, Yau S, Mari F, Bruttini M, Ariani F, Dahan K, Smeets B, Antignac C, Flinter F, Renieri A. Evidence of digenic inheritance in Alport syndrome. J Med Genet 2015; 52:163-74. [PMID: 25575550 DOI: 10.1136/jmedgenet-2014-102822] [Citation(s) in RCA: 110] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Alport syndrome is a clinically heterogeneous, progressive nephropathy caused by mutations in collagen IV genes, namely COL4A3 and COL4A4 on chromosome 2 and COL4A5 on chromosome X. The wide phenotypic variability and the presence of incomplete penetrance suggest that a simple Mendelian model cannot completely explain the genetic control of this disease. Therefore, we explored the possibility that Alport syndrome is under digenic control. METHODS Using massively parallel sequencing, we identified 11 patients who had pathogenic mutations in two collagen IV genes. For each proband, we ascertained the presence of the same mutations in up to 12 members of the extended family for a total of 56 persons studied. RESULTS Overall, 23 mutations were found. Individuals with two pathogenic mutations in different genes had a mean age of renal function deterioration intermediate with respect to the autosomal-dominant form and the autosomal-recessive one, in line with molecule stoichiometry of the disruption of the type IV collagen triple helix. CONCLUSIONS Segregation analysis indicated three possible digenic segregation models: (i) autosomal inheritance with mutations on different chromosomes, resembling recessive inheritance (five families); (ii) autosomal inheritance with mutations on the same chromosome resembling dominant inheritance (two families) and (iii) unlinked autosomal and X-linked inheritance having a peculiar segregation (four families). This pedigree analysis provides evidence for digenic inheritance of Alport syndrome. Clinical geneticists and nephrologists should be aware of this possibility in order to more accurately assess inheritance probabilities, predict prognosis and identify other family members at risk.
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Affiliation(s)
- Maria Antonietta Mencarelli
- Medical Genetics, University of Siena, Siena, Italy Genetica Medica, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Laurence Heidet
- APHP, Centre de Référence des Maladies Rénales Héréditaires de l'Enfant et de l'Adulte (MARHEA), Service de Néphrologie Pédiatrique, Hôpital Necker-Enfants Malades, Paris, France
| | - Helen Storey
- Molecular Genetics Laboratory, Guy's Hospital, London, UK
| | - Michel van Geel
- Clinical Genetics, Maastricht University Medical Centre, Maastricht, the Netherlands
| | - Bertrand Knebelmann
- APHP, Centre de Référence des Maladies Rénales Héréditaires de l'Enfant et de l'Adulte (MARHEA), Service de Néphrologie Pédiatrique, Hôpital Necker-Enfants Malades, Paris, France
| | | | - Nunzia Miglietti
- Clinica Pediatrica, Azienda Ospedaliera Spedali Civili, Brescia, Italy
| | | | | | - John A Sayer
- Institute of Genetic Medicine, Newcastle University, International Centre for Life, Central Parkway, Newcastle upon Tyne, UK
| | | | - Shu Yau
- Molecular Genetics Laboratory, Guy's Hospital, London, UK
| | - Francesca Mari
- Medical Genetics, University of Siena, Siena, Italy Genetica Medica, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Mirella Bruttini
- Medical Genetics, University of Siena, Siena, Italy Genetica Medica, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Francesca Ariani
- Medical Genetics, University of Siena, Siena, Italy Genetica Medica, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Karin Dahan
- Université Catholique de Louvain, Louvain, Belgium
| | - Bert Smeets
- Clinical Genetics, Maastricht University Medical Centre, Maastricht, the Netherlands
| | - Corinne Antignac
- Inserm UMR 1163, Laboratory of Inherited Kidney Diseases, Paris, France Paris Descartes-Sorbonne Paris Cité Université, Imagine Institute, Paris, France APHP, Department of Genetics, Hôpital Necker-Enfants Malades, Paris, France
| | - Frances Flinter
- Department of Clinical Genetics, Guy's & St Thomas' NHS Foundation Trust, Guy's Hospital, London, UK
| | - Alessandra Renieri
- Medical Genetics, University of Siena, Siena, Italy Genetica Medica, Azienda Ospedaliera Universitaria Senese, Siena, Italy
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20
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Lennon R, Stuart HM, Bierzynska A, Randles MJ, Kerr B, Hillman KA, Batra G, Campbell J, Storey H, Flinter FA, Koziell A, Welsh GI, Saleem MA, Webb NJA, Woolf AS. Coinheritance of COL4A5 and MYO1E mutations accentuate the severity of kidney disease. Pediatr Nephrol 2015; 30:1459-65. [PMID: 25739341 PMCID: PMC4536279 DOI: 10.1007/s00467-015-3067-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2014] [Revised: 02/02/2015] [Accepted: 02/06/2015] [Indexed: 12/11/2022]
Abstract
BACKGROUND Mutations in podocyte and basement membrane genes are associated with a growing spectrum of glomerular disease affecting adults and children. Investigation of familial cases has helped to build understanding of both normal physiology and disease. METHODS We investigated a consanguineous family with a wide clinical phenotype of glomerular disease using clinical, histological, and new genetic studies. RESULTS We report striking variability in severity of nephropathy within an X-linked Alport syndrome (XLAS) family. Four siblings each carried a mutant COL4A5 allele, p.(Gly953Val) and p.(Gly1033Arg). Two boys had signs limited to hematuria and mild/moderate proteinuria. In striking contrast, a sister presented with end-stage renal disease (ESRD) at 8 years of age and an infant brother presented with nephrotic syndrome, progressing to ESRD by 3 years of age. Both were subsequently found to have homozygous variants in MYO1E, p.(Lys118Glu) and p.(Thr876Arg). MYO1E is a gene implicated in focal segmental glomerulosclerosis and it encodes a podocyte-expressed non-muscle myosin. Bioinformatic modeling demonstrated that the collagen IV-alpha3,4,5 extracellular network connected via known protein-protein interactions to intracellular myosin 1E. CONCLUSIONS COL4A5 and MYO1E mutations may summate to perturb common signaling pathways, resulting in more severe disease than anticipated independently. We suggest screening for MYO1E and other non-COL4 'podocyte gene' mutations in XLAS when clinical nephropathy is more severe than expected for an individual's age and sex.
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Affiliation(s)
- Rachel Lennon
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester, Michael Smith Building, M13 9PT, Manchester, UK,
| | | | | | - Michael J. Randles
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester, Michael Smith Building, M13 9PT Manchester, UK ,Institute of Human Development, Faculty of Human Sciences, University of Manchester, Manchester, UK
| | - Bronwyn Kerr
- Manchester Centre for Genomic Medicine, Manchester, UK
| | | | - Gauri Batra
- Department of Paediatric Histopathology, CMFT, Manchester, UK
| | | | - Helen Storey
- Molecular Genetics, Viapath, Guy’s Hospital, London, UK
| | - Frances A. Flinter
- Clinical Genetics Department, Guy’s and St Thomas’ NHS Foundation Trust, London, UK
| | - Ania Koziell
- Guy’s and St Thomas’ NHS Foundation Trust and King’s College London, London, UK
| | | | | | - Nicholas J. A. Webb
- Department of Paediatric Nephrology, Central Manchester University Hospitals NHS Foundation Trust (CMFT), Manchester Academic Health Science Centre (MAHSC), Manchester, UK
| | - Adrian S. Woolf
- Institute of Human Development, Faculty of Human Sciences, University of Manchester, Manchester, UK ,Department of Paediatric Nephrology, Central Manchester University Hospitals NHS Foundation Trust (CMFT), Manchester Academic Health Science Centre (MAHSC), Manchester, UK
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Savige J, Ars E, Cotton RGH, Crockett D, Dagher H, Deltas C, Ding J, Flinter F, Pont-Kingdon G, Smaoui N, Torra R, Storey H. DNA variant databases improve test accuracy and phenotype prediction in Alport syndrome. Pediatr Nephrol 2014; 29:971-7. [PMID: 23720012 DOI: 10.1007/s00467-013-2486-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2012] [Revised: 01/02/2013] [Accepted: 01/03/2013] [Indexed: 01/18/2023]
Abstract
X-linked Alport syndrome is a form of progressive renal failure caused by pathogenic variants in the COL4A5 gene. More than 700 variants have been described and a further 400 are estimated to be known to individual laboratories but are unpublished. The major genetic testing laboratories for X-linked Alport syndrome worldwide have established a Web-based database for published and unpublished COL4A5 variants ( https://grenada.lumc.nl/LOVD2/COL4A/home.php?select_db=COL4A5 ). This conforms with the recommendations of the Human Variome Project: it uses the Leiden Open Variation Database (LOVD) format, describes variants according to the human reference sequence with standardized nomenclature, indicates likely pathogenicity and associated clinical features, and credits the submitting laboratory. The database includes non-pathogenic and recurrent variants, and is linked to another COL4A5 mutation database and relevant bioinformatics sites. Access is free. Increasing the number of COL4A5 variants in the public domain helps patients, diagnostic laboratories, clinicians, and researchers. The database improves the accuracy and efficiency of genetic testing because its variants are already categorized for pathogenicity. The description of further COL4A5 variants and clinical associations will improve our ability to predict phenotype and our understanding of collagen IV biochemistry. The database for X-linked Alport syndrome represents a model for databases in other inherited renal diseases.
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Wang Y, Sivakumar V, Mohammad M, Colville D, Storey H, Flinter F, Dagher H, Savige J. Clinical and genetic features in autosomal recessive and X-linked Alport syndrome. Pediatr Nephrol 2014; 29:391-6. [PMID: 24178893 DOI: 10.1007/s00467-013-2643-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Revised: 06/07/2013] [Accepted: 06/10/2013] [Indexed: 11/30/2022]
Abstract
BACKGROUND This study determined the family history and clinical features that suggested autosomal recessive rather than X-linked Alport syndrome. METHODS All patients had the diagnosis of Alport syndrome and the mode of inheritance confirmed by genetic testing, and underwent examination at a single centre. RESULTS Patients comprised 9 males and 6 females with autosomal recessive Alport syndrome, and 18 males and 22 females with X-linked disease. Fourteen (93 %) individuals with autosomal recessive Alport syndrome developed early end-stage renal failure, all 15 had hearing loss, and most had lenticonus (12, 80 %), and a central (13, 87 %) or peripheral (13, 87 %) retinopathy. These features occurred as often as in males with X-linked disease. Females with autosomal recessive inheritance were less likely to have an affected family member in another generation (p = 0.01) than females with X-linked disease. They were more likely to have renal failure (p = 0.003), hearing loss (p = 0.02) and lenticonus (p < 0.001). Fifty percent had a central retinopathy compared with 18 % with X-linked disease (p = 0.14), but peripheral retinopathy prevalence was not different (p = 0.64). Nonsense mutations accounted for 67 % (8/12) of these disease-causing mutations. CONCLUSIONS Autosomal recessive inheritance is increased in females with Alport syndrome and early onset renal failure, hearing loss, lenticonus, and, possibly, central retinopathy.
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Affiliation(s)
- Yanyan Wang
- Department of Medicine (Northern Health), The University of Melbourne, Epping, VIC, 3076, Australia
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A female with X-linked Alport syndrome and compound heterozygous COL4A5 mutations. Pediatr Nephrol 2014; 29:481-5. [PMID: 24337245 DOI: 10.1007/s00467-013-2682-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Revised: 10/21/2013] [Accepted: 10/25/2013] [Indexed: 10/25/2022]
Abstract
BACKGROUND Female subjects with X-linked Alport syndrome have a single COL4A5 mutation, germ cell mosaicism in affected tissues and typically develop renal failure later or less often than male subjects. Women with two mutations are exceedingly rare, and usually have consanguineous parents or uniparental disomy. We describe here a 20-year-old woman who inherited two different COL4A5 variants, one from her father (c.2677G>C) and one from her mother (c.384 +1 G>A). CASE-DIAGNOSIS/TREATMENT The index case had normal renal function, proteinuria and no clinically detectable hearing loss, or ocular abnormalities. Her father and paternal uncle developed end-stage renal disease at 37 and 28 years respectively, together with hearing loss, but not lenticonus or central retinopathy. Her mother had mildly impaired renal function, proteinuria, hearing loss, but no ocular abnormalities. Her maternal grandfather and 22-year-old brother, both with this mutation, developed renal failure by 28 years with hearing loss, or had proteinuria and hearing loss respectively. CONCLUSION The index case has clinical features consistent with germ cell mosaicism of two COL45A mutations associated with adult-onset renal failure, but no ocular abnormalities. Her risk of renal failure is high, but the rate of progression to end-stage disease depends on the underlying mutations, and disease modification with renin-angiotensin blockade.
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Ahmed F, Kamae KK, Jones DJ, Deangelis MM, Hageman GS, Gregory MC, Bernstein PS. Temporal macular thinning associated with X-linked Alport syndrome. JAMA Ophthalmol 2013; 131:777-82. [PMID: 23572034 DOI: 10.1001/jamaophthalmol.2013.1452] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
IMPORTANCE Optical coherence tomography (OCT) findings of temporal macular thinning are important in the diagnosis and prognosis of X-linked Alport syndrome (XLAS). OBJECTIVES To report OCT findings and severity of temporal macular thinning in a cohort with XLAS and to correlate these and other ocular findings with mutation genotype. DESIGN Patients with XLAS underwent genotyping for COL4A5 mutations and complete eye examinations with retinal imaging using spectral domain OCT and fundus photography. Temporal macular thinning was calculated from OCT measurements by comparing the ratio of the retinal thickness of the temporal to the nasal subfields with a published normative database. SETTING University departments of ophthalmology and nephrology. PARTICIPANTS Thirty-two patients from 24 families. MAIN OUTCOME AND MEASURES Temporal thinning index calculated from spectral domain OCT scans. RESULTS All study patients had a mutation associated with the X-linked COL4A5 gene. Eleven different mutations were identified. Eleven of 32 patients (34%) expressed the L1649R mutation. Of a total of 63 eyes with available OCT scans, 44 (70%) had severe pathological temporal macular thinning. The L1649R mutation was associated with the least amount of severe temporal macular thinning and later onset of renal failure. CONCLUSIONS AND RELEVANCE Temporal macular thinning is a prominent sign associated with XLAS, suggesting that OCT measurements are essential in the diagnosis and prognosis of the disease. The L1649R mutation in the COL4A5 gene causes a relatively mild form of XLAS characterized by late-onset renal failure and less frequent, severe temporal macular thinning relative to other COL4A5 mutations. The pathological basis for the retinal abnormalities of XLAS remains to be established.
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Affiliation(s)
- Faisal Ahmed
- Department of Ophthalmology and Visual Sciences, John A Moran Eye Center, University of Utah, University of Utah Health Sciences Center Salt Lake City, UT 84132, USA
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Pierides A, Voskarides K, Kkolou M, Hadjigavriel M, Deltas C. X-linked, COL4A5 hypomorphic Alport mutations such as G624D and P628L may only exhibit thin basement membrane nephropathy with microhematuria and late onset kidney failure. Hippokratia 2013; 17:207-213. [PMID: 24470729 PMCID: PMC3872455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Alport syndrome (ATS) results from X-linked, COL4A5 mutations (85%) or from autosomal recessive homozygous or compound heterozygous COL4A3/A4 mutations (15%), associated with alternate thinning and thickening as well as splitting and lamellation of the glomerular basement membranes. In contrast, familial microhematuria with thin basement membranes is thought to result from heterozygous COL4A3/A4 mutations. This absolute separation may not always be true. Renal biopsies and molecular genetics were used to study microhematuric families in the Hellenic population we serve. The COL4A5 gene was studied by PCR and direct re-sequencing for new mutations, while PCR-RFLP was used to identify more carriers of known COL4A5 and COL4A3/A4 mutations. Molecular genetics in two undiagnosed microhematuric Cypriot families, revealed COL4A5 mutation P628L indicating X-linked ATS. Of nine males, seven developed end stage kidney disease (ESKD) between 31 and 56, while two are well at 51 and 57, exhibiting microhematuria and thin basement membrane nephropathy (TBMN). COL4A5 mutation G624D was also identified in six Greek families. Seventy five members had DNA tests and 37 proved positive. Four positive males developed ESKD at 61, 51, 50 and 39 years, while the remaining and all females showed only microhematuria. A literature search revealed eight papers with six similar hypomorphic COL4A5 mutations presenting as phenocopies of TBMN. In conclusion, X-linked COL4A5 ATS mutations produce a phenotypic spectrum with a) classical ATS with early onset ESKD, neurosensory deafness and ocular defects b) males with only ESKD and late deafness and c) males due to missense mutations, such as G624D and P628L that may only exhibit microhematuria, TBMN, mild chronic renal failure (CRF) or late onset ESKD. Consequently when investigating "benign familial hematuria" these and other similar X-linked COL4A5 mutations should also be searched for.
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Affiliation(s)
- A Pierides
- Department of Nephrology, Hippocrateon Hospital, Nicosia, Cyprus ; Department of Biological Sciences and Molecular Medicine Research Center, University of Cyprus, Nicosia, Cyprus
| | - K Voskarides
- Department of Biological Sciences and Molecular Medicine Research Center, University of Cyprus, Nicosia, Cyprus
| | - M Kkolou
- Department of Nephrology, Larnaca General Hospital, Larnaca, Cyprus
| | - M Hadjigavriel
- Department of Nephrology, Larnaca General Hospital, Larnaca, Cyprus
| | - C Deltas
- Department of Biological Sciences and Molecular Medicine Research Center, University of Cyprus, Nicosia, Cyprus
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Savige J, Gregory M, Gross O, Kashtan C, Ding J, Flinter F. Expert guidelines for the management of Alport syndrome and thin basement membrane nephropathy. J Am Soc Nephrol 2013; 24:364-75. [PMID: 23349312 DOI: 10.1681/asn.2012020148] [Citation(s) in RCA: 220] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Few prospective, randomized controlled clinical trials address the diagnosis and management of patients with Alport syndrome or thin basement membrane nephropathy. Adult and pediatric nephrologists and geneticists from four continents whose clinical practice focuses on these conditions have developed the following guidelines. The 18 recommendations are based on Level D (Expert opinion without explicit critical appraisal, or based on physiology, bench research, or first principles-National Health Service category) or Level III (Opinions of respected authorities, based on clinical experience, descriptive studies, or reports of expert committees-U.S. Preventive Services Task Force) evidence. The recommendations include the use of genetic testing as the gold standard for the diagnosis of Alport syndrome and the demonstration of its mode of inheritance; the need to identify and follow all affected members of a family with X-linked Alport syndrome, including most mothers of affected males; the treatment of males with X-linked Alport syndrome and individuals with autosomal recessive disease with renin-angiotensin system blockade, possibly even before the onset of proteinuria; discouraging the affected mothers of males with X-linked Alport syndrome from renal donation because of their own risk of kidney failure; and consideration of genetic testing to exclude X-linked Alport syndrome in some individuals with thin basement membrane nephropathy. The authors recognize that as evidence emerges, including data from patient registries, these guidelines will evolve further.
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Affiliation(s)
- Judy Savige
- Department of Medicine (Northern Health), University of Melbourne, Melbourne, Australia.
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Kruegel J, Rubel D, Gross O. Alport syndrome--insights from basic and clinical research. Nat Rev Nephrol 2012; 9:170-8. [PMID: 23165304 DOI: 10.1038/nrneph.2012.259] [Citation(s) in RCA: 165] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In 1927, Arthur C. Alport first published his description of a triad of symptoms in a family with hereditary congenital haemorrhagic nephritis, deafness and ocular changes. A few years after his death, this group of symptoms was renamed Alport syndrome. To this day, Alport syndrome still inevitably leads to end-stage renal disease and the need for renal replacement therapy, starting in young adulthood. During the past two decades, research into this rare disease has focused on the effects of mutations in collagen type IV and the role of changes in podocytes and the glomerular basement membrane that lead to early kidney fibrosis. Animal models of Alport syndrome also demonstrate the pathogenetic importance of interactions between podocytes and the extracellular matrix. Such models might also help researchers to answer basic questions about podocyte function and the development of fibrosis, and to develop new therapeutic approaches that might be of use in other kidney diseases. In this Review, we discuss the latest basic and clinical research on Alport syndrome, focusing on the roles of podocyte pathology and the extracellular matrix. We also highlight early diagnosis and treatment options for young patients with this disorder.
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Affiliation(s)
- Jenny Kruegel
- Department of Nephrology and Rheumatology, University Medicine Göttingen, Robert-Koch-Straße 40, 37075 Göttingen, Germany
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Antón-Martín P, Aparicio López C, Ramiro-León S, Santillán Garzón S, Santos-Simarro F, Gil-Fournier B. Alport Syndrome: De Novo Mutation in the COL4A5 Gene Converting Glycine 1205 to Valine. CLINICAL MEDICINE INSIGHTS-PEDIATRICS 2012; 6:41-9. [PMID: 23641165 PMCID: PMC3620815 DOI: 10.2147/cbf.s23366] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND Alport syndrome is a primary basement membrane disorder arising from mutations in genes encoding the type IV collagen protein family. It is a genetically heterogeneous disease with different mutations and forms of inheritance that presents with renal affection, hearing loss and eye defects. Several new mutations related to X-linked forms have been previously determined. METHODS We report the case of a 12 years old male and his family diagnosed with Alport syndrome after genetic analysis was performed. RESULT A new mutation determining a nucleotide change c.3614G > T (p.Gly1205Val) in hemizygosis in the COL4A5 gene was found. This molecular defect has not been previously described. CONCLUSION Molecular biology has helped us to comprehend the mechanisms of pathophysiology in Alport syndrome. Genetic analysis provides the only conclusive diagnosis of the disorder at the moment. Our contribution with a new mutation further supports the need of more sophisticated molecular methods to increase the mutation detection rates with lower costs and less time.
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Affiliation(s)
- Pilar Antón-Martín
- Department of Pediatrics, Division of Nephrology, Hospital Universitario de Getafe, Madrid, Spain
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29
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Antón-Martín P, López CA, Ramiro-León S, Garzón SS, Santos-Simarro F, Gil-Fournier B. Alport Syndrome: De Novo Mutation in the COL4A5 Gene Converting Glycine 1205 to Valine. CLINICAL MEDICINE. PEDIATRICS 2012. [DOI: 10.4137/cmped.s7509] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BackgroundAlport syndrome is a primary basement membrane disorder arising from mutations in genes encoding the type IV collagen protein family. It is a genetically heterogeneous disease with different mutations and forms of inheritance that presents with renal affection, hearing loss and eye defects. Several new mutations related to X-linked forms have been previously determined.MethodsWe report the case of a 12 years old male and his family diagnosed with Alport syndrome after genetic analysis was performed.ResultAnew mutation determining a nucleotide change C.3614G > T (p. Gly1205Val) in hemizygosis in the COL4A5 gene was found. This molecular defect has not been previously described.ConclusionMolecular biology has helped us to comprehend the mechanisms of pathophysiology in Alport syndrome. Genetic analysis provides the only conclusive diagnosis of the disorder at the moment. Our contribution with a new mutation further supports the need of more sophisticated molecular methods to increase the mutation detection rates with lower costs and less time.
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Affiliation(s)
- Pilar Antón-Martín
- Department of Pediatrics, Division of Nephrology, Hospital Universitario de Getafe, Madrid, Spain
| | - Cristina Aparicio López
- Department of Pediatrics, Division of Nephrology, Hospital Universitario de Getafe, Madrid, Spain
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Artuso R, Fallerini C, Dosa L, Scionti F, Clementi M, Garosi G, Massella L, Epistolato MC, Mancini R, Mari F, Longo I, Ariani F, Renieri A, Bruttini M. Advances in Alport syndrome diagnosis using next-generation sequencing. Eur J Hum Genet 2011; 20:50-7. [PMID: 21897443 DOI: 10.1038/ejhg.2011.164] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Alport syndrome (ATS) is a hereditary nephropathy often associated with sensorineural hypoacusis and ocular abnormalities. Mutations in the COL4A5 gene cause X-linked ATS. Mutations in COL4A4 and COL4A3 genes have been reported in both autosomal recessive and autosomal dominant ATS. The conventional mutation screening, performed by DHPLC and/or Sanger sequencing, is time-consuming and has relatively high costs because of the absence of hot spots and to the high number of exons per gene: 51 (COL4A5), 48 (COL4A4) and 52 (COL4A3). Several months are usually necessary to complete the diagnosis, especially in cases with less informative pedigrees. To overcome these limitations, we designed a next-generation sequencing (NGS) protocol enabling simultaneous detection of all possible variants in the three genes. We used a method coupling selective amplification to the 454 Roche DNA sequencing platform (Genome Sequencer junior). The application of this technology allowed us to identify the second mutation in two ATS patients (p.Ser1147Phe in COL4A3 and p.Arg1682Trp in COL4A4) and to reconsider the diagnosis of ATS in a third patient. This study, therefore, illustrates the successful application of NGS to mutation screening of Mendelian disorders with locus heterogeneity.
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Affiliation(s)
- Rosangela Artuso
- Medical Genetics Section, Biotechnology Department, University of Siena, Siena, Italy
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Savige J, Ratnaike S, Colville D. Retinal Abnormalities Characteristic of Inherited Renal Disease. J Am Soc Nephrol 2011; 22:1403-15. [DOI: 10.1681/asn.2010090965] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
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Bekheirnia MR, Reed B, Gregory MC, McFann K, Shamshirsaz AA, Masoumi A, Schrier RW. Genotype-phenotype correlation in X-linked Alport syndrome. J Am Soc Nephrol 2010; 21:876-83. [PMID: 20378821 DOI: 10.1681/asn.2009070784] [Citation(s) in RCA: 171] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Mutations in the COL4A5 gene cause X-linked Alport syndrome (XLAS). Understanding the correlation between clinical manifestations and the underlying mutations adds prognostic value to genetic testing, which is increasingly available. Our aim was to determine the association between genotype and phenotype in 681 affected male participants with XLAS from 175 US families. Hearing loss and ocular changes were present in 67 and 30% of participants, respectively. Average age of participants at onset of ESRD was 37 years for those with missense mutations, 28 years for those with splice-site mutations, and 25 years for those with truncating mutations (P < 0.0001). We demonstrated a strong relationship between mutation position and age at onset of ESRD, with younger age at onset of ESRD associated with mutations at the 5' end of the gene (hazard ratio 0.766 [95% confidence interval 0.694 to 0.846] per 1000 bp toward the 3' end; P < 0.0001). Affected participants with splice mutations or truncating mutations each had two-fold greater odds of developing eye problems than those with missense mutations; development of hearing impairment showed a similar trend. Hearing loss and ocular changes associated with mutations located closer to the 5; end of the gene. These strong genotype-phenotype correlations could potentially help in the evaluation and counseling of US families with XLAS.
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Affiliation(s)
- Mir Reza Bekheirnia
- Department of Medicine, University of Colorado Denver, Aurora, Colorado 80045, USA
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