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Munir A, Afsar S, Rehman AU. A systematic review of inherited retinal dystrophies in Pakistan: updates from 1999 to April 2023. BMC Ophthalmol 2024; 24:55. [PMID: 38317096 PMCID: PMC10840256 DOI: 10.1186/s12886-024-03319-7] [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: 06/01/2023] [Accepted: 01/19/2024] [Indexed: 02/07/2024] Open
Abstract
BACKGROUND Inherited retinal degenerations (IRDs) are a group of rare genetic conditions affecting retina of the eye that range in prevalence from 1 in 2000 to 1 in 4000 people globally. This review is based on a retrospective analysis of research articles reporting IRDs associated genetic findings in Pakistani families between 1999 and April 2023. METHODS Articles were retrieved through survey of online sources, notably, PubMed, Google Scholar, and Web of Science. Following a stringent selection criterion, a total of 126 research articles and conference abstracts were considered. All reported variants were cross-checked and validated for their correct genomic nomenclature using different online resources/databases, and their pathogenicity scores were explained as per ACMG guidelines. RESULTS A total of 277 unique sequence variants in 87 distinct genes, previously known to cause IRDs, were uncovered. In around 70% cases, parents of the index patient were consanguineously married, and approximately 88.81% of the detected variants were found in a homozygous state. Overall, more than 95% of the IRDs cases were recessively inherited. Missense variants were predominant (41.88%), followed by Indels/frameshift (26.35%), nonsense (19.13%), splice site (12.27%) and synonymous change (0.36%). Non-syndromic IRDs were significantly higher than syndromic IRDs (77.32% vs. 22.68%). Retinitis pigmentosa (RP) was the most frequently observed IRD followed by Leber's congenital amaurosis (LCA). Altogether, mutations in PDE6A gene was the leading cause of IRDs in Pakistani families followed by mutations in TULP1 gene. CONCLUSION In summary, Pakistani families are notable in expressing recessively inherited monogenic disorders including IRDs likely due to the highest prevalence of consanguinity in the country that leads to expression of rare pathogenic variants in homozygous state.
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Affiliation(s)
- Asad Munir
- Department of Zoology, Faculty of Biological and Health Sciences, Hazara University, Mansehra, 21300, Khyber Pakhtunkhwa, Pakistan
| | - Salma Afsar
- Department of Zoology, Faculty of Biological and Health Sciences, Hazara University, Mansehra, 21300, Khyber Pakhtunkhwa, Pakistan
| | - Atta Ur Rehman
- Department of Zoology, Faculty of Biological and Health Sciences, Hazara University, Mansehra, 21300, Khyber Pakhtunkhwa, Pakistan.
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2
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Marwan M, Dawood M, Ullah M, Shah IU, Khan N, Hassan MT, Karam M, Rawlins LE, Baple EL, Crosby AH, Saleha S. Unravelling the genetic basis of retinal dystrophies in Pakistani consanguineous families. BMC Ophthalmol 2023; 23:205. [PMID: 37165311 PMCID: PMC10170854 DOI: 10.1186/s12886-023-02948-8] [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: 10/19/2022] [Accepted: 04/26/2023] [Indexed: 05/12/2023] Open
Abstract
BACKGROUND Retinitis Pigmentosa (RP) is a clinically and genetically progressive retinal dystrophy associated with severe visual impairments and sometimes blindness, the most common syndromic form of which is Usher syndrome (USH). This study aimed to further increase understanding of the spectrum of RP in the Khyber Pakhtunkhwa region of Pakistan. METHODOLOGY Four consanguineous families of Pashtun ethnic group were investigated which were referred by the local collaborating ophthalmologists. In total 42 individuals in four families were recruited and investigated using whole exome and dideoxy sequencing. Among them, 20 were affected individuals including 6 in both family 1 and 2, 5 in family 3 and 3 in family 4. RESULT Pathogenic gene variants were identified in all four families, including two in cone dystrophy and RP genes in the same family (PDE6C; c.480delG, p.Asn161ThrfsTer33 and TULP1; c.238 C > T, p.Gln80Ter) with double-homozygous individuals presenting with more severe disease. Other pathogenic variants were identified in MERTK (c.2194C > T, p.Arg732Ter), RHO (c.448G > A, p.Glu150Lys) associated with non-syndromic RP, and MYO7A (c.487G > A, p.Gly163Arg) associated with USH. In addition, the reported variants were of clinical significance as the PDE6C variant was detected novel, whereas TULP1, MERTK, and MYO7A variants were detected rare and first time found segregating with retinal dystrophies in Pakistani consanguineous families. CONCLUSIONS This study increases knowledge of the genetic basis of retinal dystrophies in families from Pakistan providing information important for genetic testing and diagnostic provision particularly from the Khyber Pakhtunkhwa region.
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Affiliation(s)
- Muhammad Marwan
- Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology, Kohat, Khyber Pakhtunkhwa, 26000, Pakistan
| | - Muhammad Dawood
- Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology, Kohat, Khyber Pakhtunkhwa, 26000, Pakistan
| | - Mukhtar Ullah
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, 4031, Switzerland
- Department of Ophthalmology, University of Basel, Basel, 4056, Switzerland
| | - Irfan Ullah Shah
- Department of Ophthalmology, KMU Institute of Medical Sciences KIMS, Kohat, Khyber Pakhtunkhwa, 26000, Pakistan
| | - Niamat Khan
- Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology, Kohat, Khyber Pakhtunkhwa, 26000, Pakistan
| | - Muhammad Taimur Hassan
- Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology, Kohat, Khyber Pakhtunkhwa, 26000, Pakistan
| | - Muhammad Karam
- Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology, Kohat, Khyber Pakhtunkhwa, 26000, Pakistan
| | - Lettie E Rawlins
- Medical Research, RILD Wellcome Wolfson Centre (Level 4), Royal Devon and Exeter NHS Foundation Trust, Exeter, Devon, EX2 5DW, UK
- Peninsula Clinical Genetics Service, Royal Devon & Exeter Hospital (Heavitree), Exeter, UK
| | - Emma L Baple
- Medical Research, RILD Wellcome Wolfson Centre (Level 4), Royal Devon and Exeter NHS Foundation Trust, Exeter, Devon, EX2 5DW, UK
| | - Andrew H Crosby
- Medical Research, RILD Wellcome Wolfson Centre (Level 4), Royal Devon and Exeter NHS Foundation Trust, Exeter, Devon, EX2 5DW, UK
| | - Shamim Saleha
- Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology, Kohat, Khyber Pakhtunkhwa, 26000, Pakistan.
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3
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Peter VG, Kaminska K, Santos C, Quinodoz M, Cancellieri F, Cisarova K, Pescini Gobert R, Rodrigues R, Custódio S, Paris LP, Sousa AB, Coutinho Santos L, Rivolta C. The first genetic landscape of inherited retinal dystrophies in Portuguese patients identifies recurrent homozygous mutations as a frequent cause of pathogenesis. PNAS NEXUS 2023; 2:pgad043. [PMID: 36909829 PMCID: PMC10003751 DOI: 10.1093/pnasnexus/pgad043] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 02/01/2023] [Accepted: 02/02/2023] [Indexed: 02/15/2023]
Abstract
Inherited retinal diseases (IRDs) are a group of ocular conditions characterized by an elevated genetic and clinical heterogeneity. They are transmitted almost invariantly as monogenic traits. However, with more than 280 disease genes identified so far, association of clinical phenotypes with genotypes can be very challenging, and molecular diagnosis is essential for genetic counseling and correct management of the disease. In addition, the prevalence and the assortment of IRD mutations are often population-specific. In this work, we examined 230 families from Portugal, with individuals suffering from a variety of IRD diagnostic classes (270 subjects in total). Overall, we identified 157 unique mutations (34 previously unreported) in 57 distinct genes, with a diagnostic rate of 76%. The IRD mutational landscape was, to some extent, different from those reported in other European populations, including Spanish cohorts. For instance, the EYS gene appeared to be the most frequently mutated, with a prevalence of 10% among all IRD cases. This was, in part, due to the presence of a recurrent and seemingly founder mutation involving the deletion of exons 13 and 14 of this gene. Moreover, our analysis highlighted that as many as 51% of our cases had mutations in a homozygous state. To our knowledge, this is the first study assessing a cross-sectional genotype-phenotype landscape of IRDs in Portugal. Our data reveal a rather unique distribution of mutations, possibly shaped by a small number of rare ancestral events that have now become prevalent alleles in patients.
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Affiliation(s)
- Virginie G Peter
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), Basel 4031, Switzerland.,Department of Ophthalmology, University of Basel, Basel 4031, Switzerland.,Department of Ophthalmology, Inselspital, Bern University Hospital, Bern 3010, Switzerland
| | - Karolina Kaminska
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), Basel 4031, Switzerland.,Department of Ophthalmology, University of Basel, Basel 4031, Switzerland
| | - Cristina Santos
- Department of Ophthalmology, Instituto de Oftalmologia Dr Gama Pinto (IOGP), Lisbon 1169-019, Portugal.,iNOVA4Health, NOVA Medical School, Faculdade de Ciências Médicas, NMS, FCM, Universidade NOVA de Lisboa, Lisbon 1169-056, Portugal
| | - Mathieu Quinodoz
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), Basel 4031, Switzerland.,Department of Ophthalmology, University of Basel, Basel 4031, Switzerland.,Department of Genetics and Genome Biology, University of Leicester, Leicester LE1 7RH, UK
| | - Francesca Cancellieri
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), Basel 4031, Switzerland.,Department of Ophthalmology, University of Basel, Basel 4031, Switzerland
| | - Katarina Cisarova
- Department of Computational Biology, University of Lausanne, Lausanne 1015, Switzerland
| | | | - Raquel Rodrigues
- Department of Medical Genetics, Hospital Santa Maria, Centro Hospitalar Universitário Lisboa Norte (CHULN), Lisbon 1649-035, Portugal
| | - Sónia Custódio
- Department of Medical Genetics, Hospital Santa Maria, Centro Hospitalar Universitário Lisboa Norte (CHULN), Lisbon 1649-035, Portugal
| | - Liliana P Paris
- Department of Ophthalmology, Instituto de Oftalmologia Dr Gama Pinto (IOGP), Lisbon 1169-019, Portugal
| | - Ana Berta Sousa
- Department of Medical Genetics, Hospital Santa Maria, Centro Hospitalar Universitário Lisboa Norte (CHULN), Lisbon 1649-035, Portugal.,Laboratory of Basic Immunology, Faculty of Medicine, University of Lisbon, Lisbon 1649-028, Portugal
| | - Luisa Coutinho Santos
- Department of Ophthalmology, Instituto de Oftalmologia Dr Gama Pinto (IOGP), Lisbon 1169-019, Portugal
| | - Carlo Rivolta
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), Basel 4031, Switzerland.,Department of Ophthalmology, University of Basel, Basel 4031, Switzerland.,Department of Genetics and Genome Biology, University of Leicester, Leicester LE1 7RH, UK
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4
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Ma Y, Wang X, Shoshany N, Jiao X, Lee A, Ku G, Baple EL, Fasham J, Nadeem R, Naeem MA, Riazuddin S, Riazuddin SA, Crosby AH, Hejtmancik JF. CLCC1 c. 75C>A Mutation in Pakistani Derived Retinitis Pigmentosa Families Likely Originated With a Single Founder Mutation 2,000-5,000 Years Ago. Front Genet 2022; 13:804924. [PMID: 35391798 PMCID: PMC8980549 DOI: 10.3389/fgene.2022.804924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 03/03/2022] [Indexed: 11/13/2022] Open
Abstract
Background: A CLCC1 c. 75C > A (p.D25E) mutation has been associated with autosomal recessive pigmentosa in patients in and from Pakistan. CLCC1 is ubiquitously expressed, and knockout models of this gene in zebrafish and mice are lethal in the embryonic period, suggesting that possible retinitis pigmentosa mutations in this gene might be limited to those leaving partial activity. In agreement with this hypothesis, the mutation is the only CLCC1 mutation associated with retinitis pigmentosa to date, and all identified patients with this mutation share a common SNP haplotype surrounding the mutation, suggesting a common founder. Methods: SNPs were genotyped by a combination of WGS and Sanger sequencing. The original founder haplotype, and recombination pathways were delineated by examination to minimize recombination events. Mutation age was estimated by four methods including an explicit solution, an iterative approach, a Bayesian approach and an approach based solely on ancestral segment lengths using high density SNP data. Results: All members of each of the nine families studied shared a single autozygous SNP haplotype for the CLCC1 region ranging from approximately 1–3.5 Mb in size. The haplotypes shared by the families could be derived from a single putative ancestral haplotype with at most two recombination events. Based on the haplotype and Gamma analysis, the estimated age of the founding mutation varied from 79 to 196 generations, or approximately 2,000–5,000 years, depending on the markers used in the estimate. The DMLE (Bayesian) estimates ranged from 2,160 generations assuming a population growth rate of 0–309 generations assuming a population growth rate of 2% with broad 95% confidence intervals. Conclusion: These results provide insight into the origin of the CLCC1 mutation in the Pakistan population. This mutation is estimated to have occurred 2000–5,000 years ago and has been transmitted to affected families of Pakistani origin in geographically dispersed locations around the world. This is the only mutation in CLCC1 identified to date, suggesting that the CLCC1 gene is under a high degree of constraint, probably imposed by functional requirements for this gene during embryonic development.
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Affiliation(s)
- Yan Ma
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, Bethesda, MD, United States
| | - Xun Wang
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, Bethesda, MD, United States.,State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Nadav Shoshany
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, Bethesda, MD, United States.,Matlow's Ophthalmo-genetic Laboratory, Shamir Medical Center, Zeriffin, Israel
| | - Xiaodong Jiao
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, Bethesda, MD, United States
| | - Adrian Lee
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, Bethesda, MD, United States
| | - Gregory Ku
- Diabetes Center, University of California, San Francisco, San Francisco, CA, United States
| | - Emma L Baple
- Research, Innovation, Learning and Development (RILD) Wellcome Wolfson Centre, College of Medicine and Health, University of Exeter Medical School, Royal Devon and Exeter NHS Foundation Trust, Exeter, United Kingdom.,Peninsula Clinical Genetics Service, Royal Devon and Exeter Hospital (Heavitree), Gladstone Road, Exeter, United Kingdom
| | - James Fasham
- Research, Innovation, Learning and Development (RILD) Wellcome Wolfson Centre, College of Medicine and Health, University of Exeter Medical School, Royal Devon and Exeter NHS Foundation Trust, Exeter, United Kingdom.,Peninsula Clinical Genetics Service, Royal Devon and Exeter Hospital (Heavitree), Gladstone Road, Exeter, United Kingdom
| | - Raheela Nadeem
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Muhammad Asif Naeem
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Sheikh Riazuddin
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan.,Allama Iqbal Medical College, University of Health Sciences, Lahore, Pakistan
| | - S Amer Riazuddin
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Andrew H Crosby
- Research, Innovation, Learning and Development (RILD) Wellcome Wolfson Centre, College of Medicine and Health, University of Exeter Medical School, Royal Devon and Exeter NHS Foundation Trust, Exeter, United Kingdom
| | - J Fielding Hejtmancik
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, Bethesda, MD, United States
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5
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Dawood M, Lin S, Din TU, Shah IU, Khan N, Jan A, Marwan M, Sultan K, Nowshid M, Tahir R, Ahmed AN, Yasin M, Baple EL, Crosby AH, Saleha S. Novel mutations in PDE6A and CDHR1 cause retinitis pigmentosa in Pakistani families. Int J Ophthalmol 2021; 14:1843-1851. [PMID: 34926197 PMCID: PMC8640774 DOI: 10.18240/ijo.2021.12.06] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 08/11/2021] [Indexed: 11/23/2022] Open
Abstract
AIM To investigate the genetic basis of autosomal recessive retinitis pigmentosa (arRP) in two consanguineous/ endogamous Pakistani families. METHODS Whole exome sequencing (WES) was performed on genomic DNA samples of patients with arRP to identify disease causing mutations. Sanger sequencing was performed to confirm familial segregation of identified mutations, and potential pathogenicity was determined by predictions of the mutations' functions. RESULTS A novel homozygous frameshift mutation [NM_000440.2:c.1054delG, p. (Gln352Argfs*4); Chr5:g.149286886del (GRCh37)] in the PDE6A gene in an endogamous family and a novel homozygous splice site mutation [NM_033100.3:c.1168-1G>A, Chr10:g.85968484G>A (GRCh37)] in the CDHR1 gene in a consanguineous family were identified. The PDE6A variant p. (Gln352Argfs*4) was predicted to be deleterious or pathogenic, whilst the CDHR1 variant c.1168-1G>A was predicted to result in potential alteration of splicing. CONCLUSION This study expands the spectrum of genetic variants for arRP in Pakistani families.
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Affiliation(s)
- Muhammad Dawood
- Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology (KUST), Kohat 26000, Khyber Pakhtunkhwa, Pakistan
| | - Siying Lin
- Medical Research, RILD Wellcome Wolfson Centre (Level 4), Royal Devon and Exeter NHS Foundation Trust, Exeter, Devon EX2 5DW, UK
| | - Taj Ud Din
- Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology (KUST), Kohat 26000, Khyber Pakhtunkhwa, Pakistan
| | - Irfan Ullah Shah
- Department of Ophthalmology, KMU Institute of Medical Sciences (KIMS) Kohat 26000, Khyber Pakhtunkhwa, Pakistan
| | - Niamat Khan
- Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology (KUST), Kohat 26000, Khyber Pakhtunkhwa, Pakistan
| | - Abid Jan
- Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology (KUST), Kohat 26000, Khyber Pakhtunkhwa, Pakistan
| | - Muhammad Marwan
- Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology (KUST), Kohat 26000, Khyber Pakhtunkhwa, Pakistan
| | - Komal Sultan
- Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology (KUST), Kohat 26000, Khyber Pakhtunkhwa, Pakistan
| | - Maha Nowshid
- Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology (KUST), Kohat 26000, Khyber Pakhtunkhwa, Pakistan
| | - Raheel Tahir
- Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology (KUST), Kohat 26000, Khyber Pakhtunkhwa, Pakistan
| | - Asif Naveed Ahmed
- Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology (KUST), Kohat 26000, Khyber Pakhtunkhwa, Pakistan
| | - Muhammad Yasin
- Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology (KUST), Kohat 26000, Khyber Pakhtunkhwa, Pakistan
| | - Emma L. Baple
- Medical Research, RILD Wellcome Wolfson Centre (Level 4), Royal Devon and Exeter NHS Foundation Trust, Exeter, Devon EX2 5DW, UK
| | - Andrew H. Crosby
- Medical Research, RILD Wellcome Wolfson Centre (Level 4), Royal Devon and Exeter NHS Foundation Trust, Exeter, Devon EX2 5DW, UK
| | - Shamim Saleha
- Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology (KUST), Kohat 26000, Khyber Pakhtunkhwa, Pakistan
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Exploring the Genetic Landscape of Retinal Diseases in North-Western Pakistan Reveals a High Degree of Autozygosity and a Prevalent Founder Mutation in ABCA4. Genes (Basel) 2019; 11:genes11010012. [PMID: 31877759 PMCID: PMC7017091 DOI: 10.3390/genes11010012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 12/16/2019] [Accepted: 12/17/2019] [Indexed: 12/21/2022] Open
Abstract
Variants in more than 271 different genes have been linked to hereditary retinal diseases, making comprehensive genomic approaches mandatory for accurate diagnosis. We explored the genetic landscape of retinal disorders in consanguineous families from North-Western Pakistan, harboring a population of approximately 35 million inhabitants that remains relatively isolated and highly inbred (~50% consanguinity). We leveraged on the high degree of consanguinity by applying genome-wide high-density single-nucleotide polymorphism (SNP) genotyping followed by targeted Sanger sequencing of candidate gene(s) lying inside autozygous intervals. In addition, we performed whole-exome sequencing (WES) on at least one proband per family. We identified 7 known and 4 novel variants in a total of 10 genes (ABCA4, BBS2, CNGA1, CNGA3, CNGB3, MKKS, NMNAT1, PDE6B, RPE65, and TULP1) previously known to cause inherited retinal diseases. In spite of all families being consanguineous, compound heterozygosity was detected in one family. All homozygous pathogenic variants resided in autozygous intervals ≥2.0 Mb in size. Putative founder variants were observed in the ABCA4 (NM_000350.2:c.214G>A; p.Gly72Arg; ten families) and NMNAT1 genes (NM_022787.3:c.25G>A; p.Val9Met; two families). We conclude that geographic isolation and sociocultural tradition of intrafamilial mating in North-Western Pakistan favor both the clinical manifestation of rare “generic” variants and the prevalence of founder mutations.
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Abduljaleel Z. Comprehensive structure-function analysis of causative variants in retinal pigment epithelium specific 65 kDa protein associated Leber Congenital Amaurosis. Noncoding RNA Res 2019; 4:121-127. [PMID: 32072079 PMCID: PMC7012777 DOI: 10.1016/j.ncrna.2019.11.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 11/07/2019] [Accepted: 11/08/2019] [Indexed: 12/23/2022] Open
Abstract
A recent study published to screen RPE65 in 187 families with Leber Congenital Amaurosis (LCA) by Zilin Zhong in 2019. There are seven novel variants were identified in RPE65, which was associated with LCA, but among only five were missense mutations [(c.124C > T, p.(Leu42Phe), c.149T > C, p. (Phe50Ser), c.340A > C, p.(Asn114His), c.425A > G, p.(Asp142Gly) and c.1399C > G, p.(Pro467Ala)] in the Chinese population and potentially facilitates its clinical implementation. Further in-continuation of this study to the target of five novel missense mutations were the analysis of both structural and functional impact by the molecular dynamics and simulation. The result of five missense mutations might in critical structural alterations of RPE65 protein, disrupt its membrane association or rescue the activity of enzyme due to thermodynamics stability, and for this reason impair its isomerohydrolase activity, resulting in retinal dystrophy. These observations suggest that the reduced protein stability and altered subcellular localization of RPE65 might signify a mechanism for these mutations to lead to vision loss in LCA patients.
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Affiliation(s)
- Zainularifeen Abduljaleel
- Department of Medical Genetics, Umm Al-Qura University, P.O. Box 715, Makkah, 21955, Saudi Arabia.,Science and Technology Unit, Umm Al Qura University, P.O. Box 715, Makkah, 21955, Saudi Arabia.,Bircham International University, Av. Sierra, 2, 28691, Villanueva de La Cañada, Madrid, Spain
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8
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Xu K, Xie Y, Sun T, Zhang X, Chen C, Li Y. Genetic and clinical findings in a Chinese cohort with Leber congenital amaurosis and early onset severe retinal dystrophy. Br J Ophthalmol 2019; 104:932-937. [PMID: 31630094 DOI: 10.1136/bjophthalmol-2019-314281] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 09/01/2019] [Accepted: 09/29/2019] [Indexed: 01/01/2023]
Abstract
BACKGROUND Leber congenital amaurosis (LCA) and early onset severe retinal dystrophy (EOSRD) are clinically and genetically heterogeneous inherited retinal disorders that cause severe visual impairment in children. The objective of this study was to describe the mutation profile and phenotypic characteristics in Chinese patients with LCA or EOSRD. METHODS Retrospective consecutive case series (2010-2017) study was performed in 148 probands (91 with LCA and 57 with EOSRD). All patients underwent ophthalmic evaluation. Mutations were revealed using targeted next-generation sequencing, followed by Sanger DNA-sequencing and real-time quantitative PCR analysis. RESULTS We identified two diseasing-causing mutations in 88 unrelated patients, heterozygous autosomal dominant mutations in 11 probands and X-linked hemizygous mutations in 11 patients, for an overall mutation detection rate of 74.3% (110/148). We detected 158 different disease-causing mutations involving 14 LCA genes, 16 retinitis pigmentosa or cone-rod dystrophy genes and 3 syndromic retinal dystrophy genes. Of these 158 mutations, 98 were novel. The most common mutation was p.Q141X of AIPL1, with a gene-specific allele frequency of 60%. The first five most frequently mutated genes were AIPL1 (11.0%), RPGRIP1 (8.8%) and CEP290, GUCY2D and RPE65 (each 7.7%) in the patients with LCA and RPGR (12.3%), CRB1 (10.5%), RPE65 (10.5%), RDH12 (7.0%) and RP2 (5.3%) in the patients with EOSRD. CONCLUSIONS Our results revealed that the mutation spectrum of patients with LCA differs from that of the patients with EOSRD and established the configuration of the mutation frequencies for each LCA gene in Chinese patients, thereby providing essential information for future genetic counselling and gene therapy.
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Affiliation(s)
- Ke Xu
- Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing Tongren Eye Center, Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Yue Xie
- Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing Tongren Eye Center, Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Tengyang Sun
- Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing Tongren Eye Center, Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Xiaohui Zhang
- Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing Tongren Eye Center, Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Chunjie Chen
- Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing Tongren Eye Center, Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Yang Li
- Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing Tongren Eye Center, Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
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9
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Nikopoulos K, Cisarova K, Quinodoz M, Koskiniemi-Kuendig H, Miyake N, Farinelli P, Rehman AU, Khan MI, Prunotto A, Akiyama M, Kamatani Y, Terao C, Miya F, Ikeda Y, Ueno S, Fuse N, Murakami A, Wada Y, Terasaki H, Sonoda KH, Ishibashi T, Kubo M, Cremers FPM, Kutalik Z, Matsumoto N, Nishiguchi KM, Nakazawa T, Rivolta C. A frequent variant in the Japanese population determines quasi-Mendelian inheritance of rare retinal ciliopathy. Nat Commun 2019; 10:2884. [PMID: 31253780 PMCID: PMC6599023 DOI: 10.1038/s41467-019-10746-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 05/23/2019] [Indexed: 12/21/2022] Open
Abstract
Hereditary retinal degenerations (HRDs) are Mendelian diseases characterized by progressive blindness and caused by ultra-rare mutations. In a genomic screen of 331 unrelated Japanese patients, we identify a disruptive Alu insertion and a nonsense variant (p.Arg1933*) in the ciliary gene RP1, neither of which are rare alleles in Japan. p.Arg1933* is almost polymorphic (frequency = 0.6%, amongst 12,000 individuals), does not cause disease in homozygosis or heterozygosis, and yet is significantly enriched in HRD patients (frequency = 2.1%, i.e., a 3.5-fold enrichment; p-value = 9.2 × 10-5). Familial co-segregation and association analyses show that p.Arg1933* can act as a Mendelian mutation in trans with the Alu insertion, but might also associate with disease in combination with two alleles in the EYS gene in a non-Mendelian pattern of heredity. Our results suggest that rare conditions such as HRDs can be paradoxically determined by relatively common variants, following a quasi-Mendelian model linking monogenic and complex inheritance.
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Affiliation(s)
- Konstantinos Nikopoulos
- Unit of Medical Genetics, Department of Computational Biology, University of Lausanne, 1015, Lausanne, Switzerland
- Service of Medical Genetics, Lausanne University Hospital (CHUV), 1011, Lausanne, Switzerland
| | - Katarina Cisarova
- Unit of Medical Genetics, Department of Computational Biology, University of Lausanne, 1015, Lausanne, Switzerland
| | - Mathieu Quinodoz
- Unit of Medical Genetics, Department of Computational Biology, University of Lausanne, 1015, Lausanne, Switzerland
| | - Hanna Koskiniemi-Kuendig
- Unit of Medical Genetics, Department of Computational Biology, University of Lausanne, 1015, Lausanne, Switzerland
| | - Noriko Miyake
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, 236-0004, Japan
| | - Pietro Farinelli
- Unit of Medical Genetics, Department of Computational Biology, University of Lausanne, 1015, Lausanne, Switzerland
| | - Atta Ur Rehman
- Unit of Medical Genetics, Department of Computational Biology, University of Lausanne, 1015, Lausanne, Switzerland
| | - Muhammad Imran Khan
- Department of Human Genetics, Radboud University Medical Center, 6500 HB, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, 6525 GA, Nijmegen, The Netherlands
| | - Andrea Prunotto
- Unit of Medical Genetics, Department of Computational Biology, University of Lausanne, 1015, Lausanne, Switzerland
| | - Masato Akiyama
- Laboratory for Statistical Analysis, RIKEN Center for Integrative Medical Sciences, Yokohama, 230-0045, Japan
| | - Yoichiro Kamatani
- Laboratory for Statistical Analysis, RIKEN Center for Integrative Medical Sciences, Yokohama, 230-0045, Japan
| | - Chikashi Terao
- Laboratory for Statistical Analysis, RIKEN Center for Integrative Medical Sciences, Yokohama, 230-0045, Japan
| | - Fuyuki Miya
- Department of Medical Science Mathematics, Medical Research Institute, Tokyo Medical and Dental University, Tokyo, 113-8510, Japan
| | - Yasuhiro Ikeda
- Department of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, 812-8582, Japan
| | - Shinji Ueno
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan
| | - Nobuo Fuse
- Department of Integrative Genomics, Tohoku Medical Megabank Organization, Sendai, 980-8573, Japan
| | - Akira Murakami
- Department of Ophthalmology, Juntendo University School of Medicine, Tokyo, 113-8421, Japan
| | - Yuko Wada
- Yuko Wada Eye Clinic, Sendai, 980-0011, Japan
| | - Hiroko Terasaki
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan
| | - Koh-Hei Sonoda
- Department of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, 812-8582, Japan
| | - Tatsuro Ishibashi
- Department of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, 812-8582, Japan
| | - Michiaki Kubo
- RIKEN Center for Integrative Medical Sciences, Yokohama, 230-0045, Japan
| | - Frans P M Cremers
- Department of Human Genetics, Radboud University Medical Center, 6500 HB, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, 6525 GA, Nijmegen, The Netherlands
| | - Zoltán Kutalik
- Institute of Social and Preventive Medicine, Lausanne University Hospital, 1011, Lausanne, Switzerland
| | - Naomichi Matsumoto
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, 236-0004, Japan
| | - Koji M Nishiguchi
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, 980-8574, Japan
- Department of Advanced Ophthalmic Medicine, Tohoku University Graduate School of Medicine, Sendai, 980-8574, Japan
| | - Toru Nakazawa
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, 980-8574, Japan
- Department of Advanced Ophthalmic Medicine, Tohoku University Graduate School of Medicine, Sendai, 980-8574, Japan
| | - Carlo Rivolta
- Unit of Medical Genetics, Department of Computational Biology, University of Lausanne, 1015, Lausanne, Switzerland.
- Department of Genetics and Genome Biology, University of Leicester, Leicester, LE1 7RH, UK.
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), 4031, Basel, Switzerland.
- University of Basel, 4001, Basel, Switzerland.
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10
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Battu R, Mallipatna A, Elackatt NJ, Schouten JSAG, Webers CAB. Challenges of managing retinal dystrophies: An experience from south India. Ophthalmic Genet 2017; 39:1-3. [PMID: 28704110 DOI: 10.1080/13816810.2017.1329446] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Rajani Battu
- a Department of Ophthalmology , Aster CMI Hospital , Bangalore , India.,b Centre for Eye Genetics and Research , Bangalore , India
| | - Ashwin Mallipatna
- c Department of Ophthalmology , Women's and Children's Hospital , Adelaide , Australia
| | - Niby Jacob Elackatt
- d Department of Genetic Counseling , Organization for Rare Diseases India , Bangalore , India
| | - Jan S A G Schouten
- e University Eye Clinic Maastricht, Maastricht University , Maastricht , the Netherlands
| | - Carroll A B Webers
- e University Eye Clinic Maastricht, Maastricht University , Maastricht , the Netherlands
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11
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Li L, Chen Y, Jiao X, Jin C, Jiang D, Tanwar M, Ma Z, Huang L, Ma X, Sun W, Chen J, Ma Y, M'hamdi O, Govindarajan G, Cabrera PE, Li J, Gupta N, Naeem MA, Khan SN, Riazuddin S, Akram J, Ayyagari R, Sieving PA, Riazuddin SA, Hejtmancik JF. Homozygosity Mapping and Genetic Analysis of Autosomal Recessive Retinal Dystrophies in 144 Consanguineous Pakistani Families. Invest Ophthalmol Vis Sci 2017; 58:2218-2238. [PMID: 28418496 PMCID: PMC5397137 DOI: 10.1167/iovs.17-21424] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Purpose The Pakistan Punjab population has been a rich source for identifying genes causing or contributing to autosomal recessive retinal degenerations (arRD). This study was carried out to delineate the genetic architecture of arRD in the Pakistani population. Methods The genetic origin of arRD in a total of 144 families selected only for having consanguineous marriages and multiple members affected with arRD was examined. Of these, causative mutations had been identified in 62 families while only the locus had been identified for an additional 15. The remaining 67 families were subjected to homozygosity exclusion mapping by screening of closely flanking microsatellite markers at 180 known candidate genes/loci followed by sequencing of the candidate gene for pathogenic changes. Results Of these 67 families subjected to homozygosity mapping, 38 showed homozygosity for at least one of the 180 regions, and sequencing of the corresponding genes showed homozygous cosegregating mutations in 27 families. Overall, mutations were detected in approximately 61.8 % (89/144) of arRD families tested, with another 10.4% (15/144) being mapped to a locus but without a gene identified. Conclusions These results suggest the involvement of unmapped novel genes in the remaining 27.8% (40/144) of families. In addition, this study demonstrates that homozygosity mapping remains a powerful tool for identifying the genetic defect underlying genetically heterogeneous arRD disorders in consanguineous marriages for both research and clinical applications.
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Affiliation(s)
- Lin Li
- Department of Ophthalmology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China 2Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Yabin Chen
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Xiaodong Jiao
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Chongfei Jin
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States 3Department of Medicine, Brookdale University Hospital and Medical Center, New York, New York, United States
| | - Dan Jiang
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Mukesh Tanwar
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States 4Department of Genetics, Maharshi Dayanand University Rohtak, Haryana, India
| | - Zhiwei Ma
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Li Huang
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States 5State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Xiaoyin Ma
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States 6Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Wenmin Sun
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States 5State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Jianjun Chen
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States 7Department of Ophthalmology, Shanghai Tenth People's Hospital, and Tongji Eye Institute, Tongji University School of Medicine, Shanghai, China
| | - Yan Ma
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Oussama M'hamdi
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Gowthaman Govindarajan
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Patricia E Cabrera
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Jiali Li
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States 5State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Nikhil Gupta
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Muhammad Asif Naeem
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Shaheen N Khan
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Sheikh Riazuddin
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan 9Allama Iqbal Medical College, University of Health Sciences, Lahore, Pakistan 10National Centre for Genetic Diseases, Shaheed Zulfiqar Ali Bhutto Medical University, Islamabad, Pakistan
| | - Javed Akram
- Allama Iqbal Medical College, University of Health Sciences, Lahore, Pakistan 10National Centre for Genetic Diseases, Shaheed Zulfiqar Ali Bhutto Medical University, Islamabad, Pakistan
| | - Radha Ayyagari
- Shiley Eye Institute, University of California-San Diego, La Jolla, California, United States
| | - Paul A Sieving
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - S Amer Riazuddin
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States 14McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States
| | - J Fielding Hejtmancik
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
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12
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Whole exome sequencing using Ion Proton system enables reliable genetic diagnosis of inherited retinal dystrophies. Sci Rep 2017; 7:42078. [PMID: 28181551 PMCID: PMC5299602 DOI: 10.1038/srep42078] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 01/05/2017] [Indexed: 01/17/2023] Open
Abstract
Inherited retinal dystrophies (IRD) comprise a wide group of clinically and genetically complex diseases that progressively affect the retina. Over recent years, the development of next-generation sequencing (NGS) methods has transformed our ability to diagnose heterogeneous diseases. In this work, we have evaluated the implementation of whole exome sequencing (WES) for the molecular diagnosis of IRD. Using Ion ProtonTM system, we simultaneously analyzed 212 genes that are responsible for more than 25 syndromic and non-syndromic IRD. This approach was used to evaluate 59 unrelated families, with the pathogenic variant(s) successfully identified in 71.18% of cases. Interestingly, the mutation detection rate varied substantially depending on the IRD subtype. Overall, we found 63 different mutations (21 novel) in 29 distinct genes, and performed in vivo functional studies to determine the deleterious impact of variants identified in MERTK, CDH23, and RPGRIP1. In addition, we provide evidences that support CDHR1 as a gene responsible for autosomal recessive retinitis pigmentosa with early macular affectation, and present data regarding the disease mechanism of this gene. Altogether, these results demonstrate that targeted WES of all IRD genes is a reliable, hypothesis-free approach, and a cost- and time-effective strategy for the routine genetic diagnosis of retinal dystrophies.
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13
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Maria M, Lamers IJC, Schmidts M, Ajmal M, Jaffar S, Ullah E, Mustafa B, Ahmad S, Nazmutdinova K, Hoskins B, van Wijk E, Koster-Kamphuis L, Khan MI, Beales PL, Cremers FPM, Roepman R, Azam M, Arts HH, Qamar R. Genetic and clinical characterization of Pakistani families with Bardet-Biedl syndrome extends the genetic and phenotypic spectrum. Sci Rep 2016; 6:34764. [PMID: 27708425 PMCID: PMC5052523 DOI: 10.1038/srep34764] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 09/09/2016] [Indexed: 11/29/2022] Open
Abstract
Bardet-Biedl syndrome (BBS) is an autosomal recessive disorder that is both genetically and clinically heterogeneous. To date 19 genes have been associated with BBS, which encode proteins active at the primary cilium, an antenna-like organelle that acts as the cell’s signaling hub. In the current study, a combination of mutation screening, targeted sequencing of ciliopathy genes associated with BBS, and whole-exome sequencing was used for the genetic characterization of five families including four with classic BBS symptoms and one BBS-like syndrome. This resulted in the identification of novel mutations in BBS genes ARL6 and BBS5, and recurrent mutations in BBS9 and CEP164. In the case of CEP164, this is the first report of two siblings with a BBS-like syndrome with mutations in this gene. Mutations in this gene were previously associated with nephronophthisis 15, thus the current results expand the CEP164-associated phenotypic spectrum. The clinical and genetic spectrum of BBS and BBS-like phenotypes is not fully defined in Pakistan. Therefore, genetic studies are needed to gain insights into genotype-phenotype correlations, which will in turn improve the clinician’s ability to make an early and accurate diagnosis, and facilitate genetic counseling, leading to directly benefiting families with affected individuals.
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Affiliation(s)
- Maleeha Maria
- Department of Biosciences, COMSATS Institute of Information Technology, Islamabad, Pakistan.,Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Ideke J C Lamers
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands.,Radboud Institute for Molecular Life Sciences, Radboud University, Nijmegen, the Netherlands
| | - Miriam Schmidts
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands.,Radboud Institute for Molecular Life Sciences, Radboud University, Nijmegen, the Netherlands.,Genetics and Genomic Medicine, UCL Institute of Child Health, 30 Guilford Street, London, UK.,Center for Pediatrics and Adolescent Medicine, Pediatric Genetics Division, University Hospital Freiburg, Germany
| | - Muhammad Ajmal
- Department of Biosciences, COMSATS Institute of Information Technology, Islamabad, Pakistan
| | | | - Ehsan Ullah
- School of Applied Sciences, Faculty of Health and Environmental Sciences, Auckland University of Technology, Auckland, New Zealand.,Auckland City Hospital, Auckland District Health Board, Auckland, New Zealand
| | - Bilal Mustafa
- Department of Biosciences, COMSATS Institute of Information Technology, Islamabad, Pakistan
| | - Shakeel Ahmad
- Department of Biosciences, COMSATS Institute of Information Technology, Islamabad, Pakistan
| | - Katia Nazmutdinova
- Genetics and Genomic Medicine, UCL Institute of Child Health, 30 Guilford Street, London, UK
| | - Bethan Hoskins
- North East Thames Regional Genetics Service, Hospital for Children, London, UK
| | - Erwin van Wijk
- Department of Otorhinolaryngology, Radboud University Medical Centre, Nijmegen, the Netherlands.,Donders Center for Neurosciences, Radboud University Nijmegen, the Netherlands
| | - Linda Koster-Kamphuis
- Department of Pediatric Nephrology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Muhammad Imran Khan
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Phil L Beales
- Genetics and Genomic Medicine, UCL Institute of Child Health, 30 Guilford Street, London, UK.,Centre for Translational Omics-GOSgene, Genetics and Genomic Medicine, UCL Institute of Child Health, London, UK
| | - Frans P M Cremers
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands.,Donders Center for Neurosciences, Radboud University Nijmegen, the Netherlands
| | - Ronald Roepman
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands.,Radboud Institute for Molecular Life Sciences, Radboud University, Nijmegen, the Netherlands
| | - Maleeha Azam
- Department of Biosciences, COMSATS Institute of Information Technology, Islamabad, Pakistan
| | - Heleen H Arts
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands.,Radboud Institute for Molecular Life Sciences, Radboud University, Nijmegen, the Netherlands.,Department of Biochemistry, University of Western Ontario, London, Ontario, Canada
| | - Raheel Qamar
- Department of Biosciences, COMSATS Institute of Information Technology, Islamabad, Pakistan.,Department of Biochemistry, Al-Nafees Medical College &Hospital, Isra University, Islamabad, Pakistan.,Pakistan Academy of Sciences, Constitution Avenue, Islamabad, Pakistan
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14
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Maranhao B, Biswas P, Gottsch ADH, Navani M, Naeem MA, Suk J, Chu J, Khan SN, Poleman R, Akram J, Riazuddin S, Lee P, Riazuddin SA, Hejtmancik JF, Ayyagari R. Investigating the Molecular Basis of Retinal Degeneration in a Familial Cohort of Pakistani Decent by Exome Sequencing. PLoS One 2015; 10:e0136561. [PMID: 26352687 PMCID: PMC4564165 DOI: 10.1371/journal.pone.0136561] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 08/04/2015] [Indexed: 11/18/2022] Open
Abstract
PURPOSE To define the molecular basis of retinal degeneration in consanguineous Pakistani pedigrees with early onset retinal degeneration. METHODS A cohort of 277 individuals representing 26 pedigrees from the Punjab province of Pakistan was analyzed. Exomes were captured with commercial kits and sequenced on an Illumina HiSeq 2500. Candidate variants were identified using standard tools and analyzed using exomeSuite to detect all potentially pathogenic changes in genes implicated in retinal degeneration. Segregation analysis was performed by dideoxy sequencing and novel variants were additionally investigated for their presence in ethnicity-matched controls. RESULTS We identified a total of nine causal mutations, including six novel variants in RPE65, LCA5, USH2A, CNGB1, FAM161A, CERKL and GUCY2D as the underlying cause of inherited retinal degenerations in 13 of 26 pedigrees. In addition to the causal variants, a total of 200 variants each observed in five or more unrelated pedigrees investigated in this study that were absent from the dbSNP, HapMap, 1000 Genomes, NHLBI ESP6500, and ExAC databases were identified, suggesting that they are common in, and unique to the Pakistani population. CONCLUSIONS We identified causal mutations associated with retinal degeneration in nearly half of the pedigrees investigated in this study through next generation whole exome sequencing. All novel variants detected in this study through exome sequencing have been cataloged providing a reference database of variants common in, and unique to the Pakistani population.
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Affiliation(s)
- Bruno Maranhao
- Department of Ophthalmology, University of California La Jolla, La Jolla, CA, United States of America
| | - Pooja Biswas
- Department of Ophthalmology, University of California La Jolla, La Jolla, CA, United States of America
| | - Alexander D. H. Gottsch
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
| | - Mili Navani
- Department of Ophthalmology, University of California La Jolla, La Jolla, CA, United States of America
| | - Muhammad Asif Naeem
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - John Suk
- Department of Ophthalmology, University of California La Jolla, La Jolla, CA, United States of America
| | - Justin Chu
- Department of Ophthalmology, University of California La Jolla, La Jolla, CA, United States of America
| | - Sheen N. Khan
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Rachel Poleman
- Department of Ophthalmology, University of California La Jolla, La Jolla, CA, United States of America
| | - Javed Akram
- Allama Iqbal Medical College, University of Health Sciences, Lahore, Pakistan
- National Centre for Genetic Diseases, Shaheed Zulfiqar Ali Bhutto Medical University, Islamabad, Pakistan
| | - Sheikh Riazuddin
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
- Allama Iqbal Medical College, University of Health Sciences, Lahore, Pakistan
- National Centre for Genetic Diseases, Shaheed Zulfiqar Ali Bhutto Medical University, Islamabad, Pakistan
| | - Pauline Lee
- Department of Ophthalmology, University of California La Jolla, La Jolla, CA, United States of America
| | - S. Amer Riazuddin
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - J. Fielding Hejtmancik
- OGVF branch, National Eye Institute, NIH, Bethesda, MD, United States of America
- * E-mail: (RA); (JFH)
| | - Radha Ayyagari
- Department of Ophthalmology, University of California La Jolla, La Jolla, CA, United States of America
- * E-mail: (RA); (JFH)
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15
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Maria M, Ajmal M, Azam M, Waheed NK, Siddiqui SN, Mustafa B, Ayub H, Ali L, Ahmad S, Micheal S, Hussain A, Shah STA, Ali SHB, Ahmed W, Khan YM, den Hollander AI, Haer-Wigman L, Collin RWJ, Khan MI, Qamar R, Cremers FPM. Homozygosity mapping and targeted sanger sequencing reveal genetic defects underlying inherited retinal disease in families from pakistan. PLoS One 2015; 10:e0119806. [PMID: 25775262 PMCID: PMC4361598 DOI: 10.1371/journal.pone.0119806] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Accepted: 01/13/2015] [Indexed: 11/18/2022] Open
Abstract
Background Homozygosity mapping has facilitated the identification of the genetic causes underlying inherited diseases, particularly in consanguineous families with multiple affected individuals. This knowledge has also resulted in a mutation dataset that can be used in a cost and time effective manner to screen frequent population-specific genetic variations associated with diseases such as inherited retinal disease (IRD). Methods We genetically screened 13 families from a cohort of 81 Pakistani IRD families diagnosed with Leber congenital amaurosis (LCA), retinitis pigmentosa (RP), congenital stationary night blindness (CSNB), or cone dystrophy (CD). We employed genome-wide single nucleotide polymorphism (SNP) array analysis to identify homozygous regions shared by affected individuals and performed Sanger sequencing of IRD-associated genes located in the sizeable homozygous regions. In addition, based on population specific mutation data we performed targeted Sanger sequencing (TSS) of frequent variants in AIPL1, CEP290, CRB1, GUCY2D, LCA5, RPGRIP1 and TULP1, in probands from 28 LCA families. Results Homozygosity mapping and Sanger sequencing of IRD-associated genes revealed the underlying mutations in 10 families. TSS revealed causative variants in three families. In these 13 families four novel mutations were identified in CNGA1, CNGB1, GUCY2D, and RPGRIP1. Conclusions Homozygosity mapping and TSS revealed the underlying genetic cause in 13 IRD families, which is useful for genetic counseling as well as therapeutic interventions that are likely to become available in the near future.
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Affiliation(s)
- Maleeha Maria
- Department of Biosciences, Commission on Science and Technology for Sustainable Development in the South Institute of Information Technology, Islamabad, Pakistan
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Muhammad Ajmal
- Department of Biosciences, Commission on Science and Technology for Sustainable Development in the South Institute of Information Technology, Islamabad, Pakistan
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Maleeha Azam
- Department of Biosciences, Commission on Science and Technology for Sustainable Development in the South Institute of Information Technology, Islamabad, Pakistan
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Nadia Khalida Waheed
- Tufts University Medical School, Boston, Massachusetts, United States of America
| | | | - Bilal Mustafa
- Department of Biosciences, Commission on Science and Technology for Sustainable Development in the South Institute of Information Technology, Islamabad, Pakistan
| | - Humaira Ayub
- Department of Biosciences, Commission on Science and Technology for Sustainable Development in the South Institute of Information Technology, Islamabad, Pakistan
| | - Liaqat Ali
- Department of Biosciences, Commission on Science and Technology for Sustainable Development in the South Institute of Information Technology, Islamabad, Pakistan
| | - Shakeel Ahmad
- Department of Biosciences, Commission on Science and Technology for Sustainable Development in the South Institute of Information Technology, Islamabad, Pakistan
| | - Shazia Micheal
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
- Department of Ophthalmology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Alamdar Hussain
- Department of Biosciences, Commission on Science and Technology for Sustainable Development in the South Institute of Information Technology, Islamabad, Pakistan
| | - Syed Tahir Abbas Shah
- Department of Biosciences, Commission on Science and Technology for Sustainable Development in the South Institute of Information Technology, Islamabad, Pakistan
| | - Syeda Hafiza Benish Ali
- Department of Biosciences, Commission on Science and Technology for Sustainable Development in the South Institute of Information Technology, Islamabad, Pakistan
- Institute of Pure and Applied Biology, Bahauddin Zakariya University, Multan, Pakistan
| | - Waqas Ahmed
- Department of Biosciences, Commission on Science and Technology for Sustainable Development in the South Institute of Information Technology, Islamabad, Pakistan
- University of Haripur, Haripur, Pakistan
| | - Yar Muhammad Khan
- Department of Chemistry, University of Science and Technology, Bannu, Pakistan
| | - Anneke I. den Hollander
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
- Department of Ophthalmology, Radboud University Medical Center, Nijmegen, the Netherlands
- Radboud Institute for Molecular Life sciences, Radboud University Nijmegen, Nijmegen, the Netherlands
| | - Lonneke Haer-Wigman
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
- Radboud Institute for Molecular Life sciences, Radboud University Nijmegen, Nijmegen, the Netherlands
| | - Rob W. J. Collin
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
- Radboud Institute for Molecular Life sciences, Radboud University Nijmegen, Nijmegen, the Netherlands
| | - Muhammad Imran Khan
- Department of Biosciences, Commission on Science and Technology for Sustainable Development in the South Institute of Information Technology, Islamabad, Pakistan
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Raheel Qamar
- Department of Biosciences, Commission on Science and Technology for Sustainable Development in the South Institute of Information Technology, Islamabad, Pakistan
- Al-Nafees Medical College & Hospital, Isra University, Islamabad, Pakistan
| | - Frans P. M. Cremers
- Department of Biosciences, Commission on Science and Technology for Sustainable Development in the South Institute of Information Technology, Islamabad, Pakistan
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
- Radboud Institute for Molecular Life sciences, Radboud University Nijmegen, Nijmegen, the Netherlands
- * E-mail:
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16
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Ravesh Z, El Asrag ME, Weisschuh N, McKibbin M, Reuter P, Watson CM, Baumann B, Poulter JA, Sajid S, Panagiotou ES, O’Sullivan J, Abdelhamed Z, Bonin M, Soltanifar M, Black GC, Din MAU, Toomes C, Ansar M, Inglehearn CF, Wissinger B, Ali M. Novel C8orf37 mutations cause retinitis pigmentosa in consanguineous families of Pakistani origin. Mol Vis 2015; 21:236-43. [PMID: 25802487 PMCID: PMC4357040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Accepted: 03/05/2015] [Indexed: 11/28/2022] Open
Abstract
PURPOSE To investigate the molecular basis of retinitis pigmentosa in two consanguineous families of Pakistani origin with multiple affected members. METHODS Homozygosity mapping and Sanger sequencing of candidate genes were performed in one family while the other was analyzed with whole exome next-generation sequencing. A minigene splicing assay was used to confirm the splicing defects. RESULTS In family MA48, a novel homozygous nucleotide substitution in C8orf37, c.244-2A>C, that disrupted the consensus splice acceptor site of exon 3 was found. The minigene splicing assay revealed that this mutation activated a cryptic splice site within exon 3, causing a 22 bp deletion in the transcript that is predicted to lead to a frameshift followed by premature protein truncation. In family MA13, a novel homozygous null mutation in C8orf37, c.555G>A, p.W185*, was identified. Both mutations segregated with the disease phenotype as expected in a recessive manner and were absent in 8,244 unrelated individuals of South Asian origin. CONCLUSIONS In this report, we describe C8orf37 mutations that cause retinal dystrophy in two families of Pakistani origin, contributing further data on the phenotype and the spectrum of mutations in this form of retinitis pigmentosa.
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Affiliation(s)
- Zeinab Ravesh
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan,Molecular Genetics Laboratory, Institute of Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Mohammed E. El Asrag
- Section of Ophthalmology and Neuroscience, Leeds Institute of Biomedical and Clinical Sciences, University of Leeds, UK,Department of Zoology, Faculty of Science, Benha University, Benha, Egypt
| | - Nicole Weisschuh
- Molecular Genetics Laboratory, Institute of Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Martin McKibbin
- The Eye Department, St. James’s University Hospital, Leeds, UK
| | - Peggy Reuter
- Molecular Genetics Laboratory, Institute of Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | | | - Britta Baumann
- Molecular Genetics Laboratory, Institute of Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - James A. Poulter
- Section of Ophthalmology and Neuroscience, Leeds Institute of Biomedical and Clinical Sciences, University of Leeds, UK
| | - Sundus Sajid
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
| | - Evangelia S. Panagiotou
- Section of Ophthalmology and Neuroscience, Leeds Institute of Biomedical and Clinical Sciences, University of Leeds, UK
| | - James O’Sullivan
- Manchester Centre for Genomic Medicine, University of Manchester, St Mary's Hospital, Manchester, UK
| | - Zakia Abdelhamed
- Section of Ophthalmology and Neuroscience, Leeds Institute of Biomedical and Clinical Sciences, University of Leeds, UK
| | - Michael Bonin
- Department of Medical Genetics, Angewandte Genomik, University of Tübingen, Tübingen, Germany
| | - Mehdi Soltanifar
- Department of Ophthalmology, Pakistan Institute of Medical Sciences, Islamabad, Pakistan
| | - Graeme C.M. Black
- Manchester Centre for Genomic Medicine, University of Manchester, St Mary's Hospital, Manchester, UK
| | | | - Carmel Toomes
- Section of Ophthalmology and Neuroscience, Leeds Institute of Biomedical and Clinical Sciences, University of Leeds, UK
| | - Muhammad Ansar
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
| | - Chris F. Inglehearn
- Section of Ophthalmology and Neuroscience, Leeds Institute of Biomedical and Clinical Sciences, University of Leeds, UK
| | - Bernd Wissinger
- Molecular Genetics Laboratory, Institute of Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Manir Ali
- Section of Ophthalmology and Neuroscience, Leeds Institute of Biomedical and Clinical Sciences, University of Leeds, UK
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17
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Siemiatkowska AM, Collin RWJ, den Hollander AI, Cremers FPM. Genomic approaches for the discovery of genes mutated in inherited retinal degeneration. Cold Spring Harb Perspect Med 2014; 4:a017137. [PMID: 24939053 PMCID: PMC4109577 DOI: 10.1101/cshperspect.a017137] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
In view of their high degree of genetic heterogeneity, inherited retinal diseases (IRDs) pose a significant challenge for identifying novel genetic causes. Thus far, more than 200 genes have been found to be mutated in IRDs, which together contain causal variants in >80% of the cases. Accurate genetic diagnostics is particularly important for isolated cases, in which X-linked and de novo autosomal dominant variants are not uncommon. In addition, new gene- or mutation-specific therapies are emerging, underlining the importance of identifying causative mutations in each individual. Sanger sequencing of selected genes followed by cost-effective targeted next-generation sequencing (NGS) can identify defects in known IRD-associated genes in the majority of the cases. Exome NGS in combination with genetic linkage or homozygosity mapping studies can aid the identification of the remaining causal genes. As these are thought to be mutated in <1% of the cases, validation through functional modeling in, for example, zebrafish and/or replication through the genotyping of large patient cohorts is required. In the near future, whole genome NGS in combination with transcriptome NGS may reveal mutations that are currently hidden in the noncoding regions of the human genome.
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Affiliation(s)
- Anna M Siemiatkowska
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Rob W J Collin
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Anneke I den Hollander
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands Department of Ophthalmology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Frans P M Cremers
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
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