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Cortinhal T, Santos C, Vaz-Pereira S, Marta A, Duarte L, Miranda V, Costa J, Sousa AB, Peter VG, Kaminska K, Rivolta C, Carvalho AL, Saraiva J, Soares CA, Silva R, Murta J, Santos LC, Marques JP. Genetic profile of syndromic retinitis pigmentosa in Portugal. Graefes Arch Clin Exp Ophthalmol 2024; 262:1883-1897. [PMID: 38189974 PMCID: PMC11106148 DOI: 10.1007/s00417-023-06360-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 12/11/2023] [Accepted: 12/28/2023] [Indexed: 01/09/2024] Open
Abstract
PURPOSE Retinitis pigmentosa (RP) comprises a genetically and clinically heterogeneous group of inherited retinal degenerations, where 20-30% of patients exhibit extra-ocular manifestations (syndromic RP). Understanding the genetic profile of RP has important implications for disease prognosis and genetic counseling. This study aimed to characterize the genetic profile of syndromic RP in Portugal. METHODS Multicenter, retrospective cohort study. Six Portuguese healthcare providers identified patients with a clinical diagnosis of syndromic RP and available genetic testing results. All patients had been previously subjected to a detailed ophthalmologic examination and clinically oriented genetic testing. Genetic variants were classified according to the American College of Medical Genetics and Genomics; only likely pathogenic or pathogenic variants were considered relevant for disease etiology. RESULTS One hundred and twenty-two patients (53.3% males) from 100 families were included. Usher syndrome was the most frequent diagnosis (62.0%), followed by Bardet-Biedl (19.0%) and Senior-Løken syndromes (7.0%). Deleterious variants were identified in 86/100 families for a diagnostic yield of 86.0% (87.1% for Usher and 94.7% for Bardet-Biedl). A total of 81 genetic variants were identified in 25 different genes, 22 of which are novel. USH2A and MYO7A were responsible for most type II and type I Usher syndrome cases, respectively. BBS1 variants were the cause of Bardet-Biedl syndrome in 52.6% of families. Best-corrected visual acuity (BCVA) records were available at baseline and last visit for 99 patients (198 eyes), with a median follow-up of 62.0 months. The mean BCVA was 56.5 ETDRS letters at baseline (Snellen equivalent ~ 20/80), declining to 44.9 ETDRS letters (Snellen equivalent ~ 20/125) at the last available follow-up (p < 0.001). CONCLUSION This is the first multicenter study depicting the genetic profile of syndromic RP in Portugal, thus contributing toward a better understanding of this heterogeneous disease group. Usher and Bardet-Biedl syndromes were found to be the most common types of syndromic RP in this large Portuguese cohort. A high diagnostic yield was obtained, highlighting current genetic testing capabilities in providing a molecular diagnosis to most affected individuals. This has major implications in determining disease-related prognosis and providing targeted genetic counseling for syndromic RP patients in Portugal.
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Affiliation(s)
- Telmo Cortinhal
- Department of Ophthalmology, Centro Hospitalar e Universitário de Coimbra (CHUC), Coimbra, Portugal
| | - Cristina Santos
- Instituto de Oftalmologia Dr. Gama Pinto (IOGP), Lisboa, Portugal
- iNOVA4Health, NOVA Medical School, Faculdade de Ciências Médicas, NMS, FCM, Universidade NOVA de Lisboa, Lisboa, Portugal
| | - Sara Vaz-Pereira
- Department of Ophthalmology, Centro Hospitalar Universitário de Lisboa Norte (CHULN), Lisboa, Portugal
- Department of Ophthalmology, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Ana Marta
- Department of Ophthalmology, Centro Hospitalar e Universitário de Santo António (CHUdSA), Porto, Portugal
- Instituto Ciências Biomédicas Abel Salazar (ICBAS), Porto, Portugal
| | - Lilianne Duarte
- Department of Ophthalmology, Centro Hospitalar de Entre Douro e Vouga (CHEDV), Santa Maria da Feira, Portugal
| | - Vitor Miranda
- Department of Ophthalmology, Centro Hospitalar de Entre Douro e Vouga (CHEDV), Santa Maria da Feira, Portugal
| | - José Costa
- Department of Ophthalmology, Hospital de Braga (HB), Braga, Portugal
| | - Ana Berta Sousa
- Medical Genetics Unit, Hospital Pediátrico, Centro Hospitalar e Universitário de Lisboa Norte (CHULN), Lisboa, Portugal
| | - Virginie G Peter
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), 4031, Basel, Switzerland
- Department of Ophthalmology, University of Basel, 4031, Basel, Switzerland
- Department of Ophthalmology, Inselspital, Bern University Hospital, 3010, Bern, Switzerland
| | - Karolina Kaminska
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), 4031, Basel, Switzerland
- Department of Ophthalmology, University of Basel, 4031, Basel, Switzerland
| | - Carlo Rivolta
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), 4031, Basel, Switzerland
- Department of Ophthalmology, University of Basel, 4031, Basel, Switzerland
- Department of Genetics and Genome Biology, University of Leicester, Leicester, LE1 7RH, United Kingdom
| | - Ana Luísa Carvalho
- Medical Genetics Unit, Centro Hospitalar e Universitário de Coimbra (CHUC), Coimbra, Portugal
- Clinical Academic Center of Coimbra (CACC), Coimbra, Portugal
- University Clinic of Medical Genetics, Faculty of Medicine, University of Coimbra (FMUC), Coimbra, Portugal
| | - Jorge Saraiva
- Medical Genetics Unit, Centro Hospitalar e Universitário de Coimbra (CHUC), Coimbra, Portugal
- Clinical Academic Center of Coimbra (CACC), Coimbra, Portugal
- University Clinic of Pediatrics, Faculty of Medicine, University of Coimbra (FMUC), Coimbra, Portugal
| | - Célia Azevedo Soares
- Medical Genetics Department, Centro de Genética Médica Jacinto Magalhães, Centro Hospitalar e Universitário do Porto (CHUP), Porto, Portugal
- Unit for Multidisciplinary Research in Biomedicine, Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal
- Medical Science Department, Universidade de Aveiro, Aveiro, Portugal
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Rufino Silva
- Department of Ophthalmology, Centro Hospitalar e Universitário de Coimbra (CHUC), Coimbra, Portugal
- Clinical Academic Center of Coimbra (CACC), Coimbra, Portugal
- University Clinic of Ophthalmology, Faculty of Medicine, University of Coimbra (FMUC), Coimbra, Portugal
| | - Joaquim Murta
- Department of Ophthalmology, Centro Hospitalar e Universitário de Coimbra (CHUC), Coimbra, Portugal
- Clinical Academic Center of Coimbra (CACC), Coimbra, Portugal
- University Clinic of Ophthalmology, Faculty of Medicine, University of Coimbra (FMUC), Coimbra, Portugal
| | | | - João Pedro Marques
- Department of Ophthalmology, Centro Hospitalar e Universitário de Coimbra (CHUC), Coimbra, Portugal.
- Clinical Academic Center of Coimbra (CACC), Coimbra, Portugal.
- University Clinic of Ophthalmology, Faculty of Medicine, University of Coimbra (FMUC), Coimbra, Portugal.
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Sanjurjo-Soriano C, Jimenez-Medina C, Erkilic N, Cappellino L, Lefevre A, Nagel-Wolfrum K, Wolfrum U, Van Wijk E, Roux AF, Meunier I, Kalatzis V. USH2A variants causing retinitis pigmentosa or Usher syndrome provoke differential retinal phenotypes in disease-specific organoids. HGG ADVANCES 2023; 4:100229. [PMID: 37654703 PMCID: PMC10465966 DOI: 10.1016/j.xhgg.2023.100229] [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: 06/05/2023] [Accepted: 08/03/2023] [Indexed: 09/02/2023] Open
Abstract
There is an emblematic clinical and genetic heterogeneity associated with inherited retinal diseases (IRDs). The most common form is retinitis pigmentosa (RP), a rod-cone dystrophy caused by pathogenic variants in over 80 different genes. Further complexifying diagnosis, different variants in individual RP genes can also alter the clinical phenotype. USH2A is the most prevalent gene for autosomal-recessive RP and one of the most challenging because of its large size and, hence, large number of variants. Moreover, USH2A variants give rise to non-syndromic and syndromic RP, known as Usher syndrome (USH) type 2, which is associated with vision and hearing loss. The lack of a clear genotype-phenotype correlation or prognostic models renders diagnosis highly challenging. We report here a long-awaited differential non-syndromic RP and USH phenotype in three human disease-specific models: fibroblasts, induced pluripotent stem cells (iPSCs), and mature iPSC-derived retinal organoids. Moreover, we identified distinct retinal phenotypes in organoids from multiple RP and USH individuals, which were validated by isogenic-corrected controls. Non-syndromic RP organoids showed compromised photoreceptor differentiation, whereas USH organoids showed a striking and unexpected cone phenotype. Furthermore, complementary clinical investigations identified macular atrophy in a high proportion of USH compared with RP individuals, further validating our observations that USH2A variants differentially affect cones. Overall, identification of distinct non-syndromic RP and USH phenotypes in multiple models provides valuable and robust readouts for testing the pathogenicity of USH2A variants as well as the efficacy of therapeutic approaches in complementary cell types.
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Affiliation(s)
- Carla Sanjurjo-Soriano
- Institute for Neurosciences of Montpellier (INM), University of Montpellier, INSERM, Montpellier, France
| | - Carla Jimenez-Medina
- Institute for Neurosciences of Montpellier (INM), University of Montpellier, INSERM, Montpellier, France
| | - Nejla Erkilic
- Institute for Neurosciences of Montpellier (INM), University of Montpellier, INSERM, Montpellier, France
| | - Luisina Cappellino
- Institute for Neurosciences of Montpellier (INM), University of Montpellier, INSERM, Montpellier, France
| | - Arnaud Lefevre
- National Reference Centre for Inherited Sensory Diseases, University of Montpellier, CHU, Montpellier, France
| | - Kerstin Nagel-Wolfrum
- Institute of Molecular Physiology, Molecular Cell Biology, and Photoreceptor Cell Biology, Johannes Gutenberg University Mainz, Mainz, Germany
- Institute of Developmental Biology and Neurobiology, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Uwe Wolfrum
- Institute of Molecular Physiology, Molecular Cell Biology, and Photoreceptor Cell Biology, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Erwin Van Wijk
- Department of Otorhinolaryngology, Hearing, & Genes, Radboud University Medical Center, Nijmegen, the Netherlands
- Donders Institute for Brain, Cognition, and Behavior, Nijmegen, the Netherlands
| | - Anne-Françoise Roux
- Institute for Neurosciences of Montpellier (INM), University of Montpellier, INSERM, Montpellier, France
- Molecular Genetics Laboratory, University of Montpellier, CHU, Montpellier, France
| | - Isabelle Meunier
- Institute for Neurosciences of Montpellier (INM), University of Montpellier, INSERM, Montpellier, France
- National Reference Centre for Inherited Sensory Diseases, University of Montpellier, CHU, Montpellier, France
| | - Vasiliki Kalatzis
- Institute for Neurosciences of Montpellier (INM), University of Montpellier, INSERM, Montpellier, France
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Li W, Jiang XS, Han DM, Gao JY, Yang ZT, Jiang L, Zhang Q, Zhang SH, Gao Y, Wu JH, Li JK. Genetic Characteristics and Variation Spectrum of USH2A-Related Retinitis Pigmentosa and Usher Syndrome. Front Genet 2022; 13:900548. [PMID: 36110214 PMCID: PMC9468824 DOI: 10.3389/fgene.2022.900548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Accepted: 06/10/2022] [Indexed: 11/13/2022] Open
Abstract
Purposes: We aimed to characterize the USH2A genotypic spectrum in a Chinese cohort and provide a detailed genetic profile for Chinese patients with USH2A-IRD.Methods: We designed a retrospective study wherein a total of 1,334 patients diagnosed with IRD were included as a study cohort, namely 1,278 RP and 56 USH patients, as well as other types of IEDs patients and healthy family members as a control cohort. The genotype-phenotype correlation of all participants with USH2A variant was evaluated.Results: Etiological mutations in USH2A, the most common cause of RP and USH, were found in 16.34% (n = 218) genetically solved IRD patients, with prevalences of 14.87% (190/1,278) and 50% (28/56). After bioinformatics and QC processing, 768 distinct USH2A variants were detected in all participants, including 136 disease-causing mutations present in 665 alleles, distributed in 5.81% of all participants. Of these 136 mutations, 43 were novel, nine were founder mutations, and two hot spot mutations with allele count ≥10. Furthermore, 38.5% (84/218) of genetically solved USH2A-IRD patients were caused by at least one of both c.2802T>G and c.8559–2 A>G mutations, and 36.9% and 69.6% of the alleles in the RP and USH groups were truncating, respectively.Conclusion: USH2A-related East Asian-specific founder and hot spot mutations were the major causes for Chinese RP and USH patients. Our study systematically delineated the genotype spectrum of USH2A-IRD, enabled accurate genetic diagnosis, and provided East Asian and other ethnicities with baseline data of a Chinese origin, which would better serve genetic counseling and therapeutic targets selection.
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Affiliation(s)
- Wei Li
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
- BGI-Shenzhen, Shenzhen, China
- *Correspondence: Wei Li, ; Ya Gao, ; Ji-Hong Wu, ; Jian-Kang Li,
| | - Xiao-Sen Jiang
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
- BGI-Shenzhen, Shenzhen, China
| | - Dong-Ming Han
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
- BGI-Shenzhen, Shenzhen, China
| | - Jia-Yu Gao
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
- BGI-Shenzhen, Shenzhen, China
| | - Zheng-Tao Yang
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
- BGI-Shenzhen, Shenzhen, China
| | - Li Jiang
- Department of Ophthalmology, Laizhou City People’s Hospital, Yantai, China
| | - Qian Zhang
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
- BGI-Shenzhen, Shenzhen, China
| | - Sheng-Hai Zhang
- Eye Institute, Eye and ENT Hospital, College of Medicine, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Visual Impairment and Restoration, Science and Technology Commission of Shanghai Municipality, Shanghai, China
| | - Ya Gao
- BGI-Shenzhen, Shenzhen, China
- *Correspondence: Wei Li, ; Ya Gao, ; Ji-Hong Wu, ; Jian-Kang Li,
| | - Ji-Hong Wu
- Eye Institute, Eye and ENT Hospital, College of Medicine, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Visual Impairment and Restoration, Science and Technology Commission of Shanghai Municipality, Shanghai, China
- *Correspondence: Wei Li, ; Ya Gao, ; Ji-Hong Wu, ; Jian-Kang Li,
| | - Jian-Kang Li
- BGI-Shenzhen, Shenzhen, China
- *Correspondence: Wei Li, ; Ya Gao, ; Ji-Hong Wu, ; Jian-Kang Li,
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Markova TG, Lalayants MR, Alekseeva NN, Ryzhkova OP, Shatokhina OL, Galeeva NM, Bliznetz EA, Weener ME, Belov OA, Chibisova SS, Polyakov AV, Tavartkiladze GA. Early audiological phenotype in patients with mutations in the USH2A gene. Int J Pediatr Otorhinolaryngol 2022; 157:111140. [PMID: 35452909 DOI: 10.1016/j.ijporl.2022.111140] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 03/16/2022] [Accepted: 04/11/2022] [Indexed: 11/27/2022]
Abstract
INTRODUCTION Nowadays, due to universal newborn hearing screening (UNHS) the number of children with mild-to-moderate hearing loss diagnosed in the first year of life has increased significantly. Aside from that, identification of the genetic cause improves the genetic counselling of the families and allows to reveal possible comorbidities which may need a special approach. OBJECTIVE To present the characteristics of the early audiologic phenotype in hearing impaired patients with biallelic mutations in the USH2A gene based on systematic analysis of the audiological data. PATIENTS AND METHODS 13 patients with mutations in the USH2A gene underwent audiological examination. Most of them were found among a large group of infants with bilateral nonsyndromic sensorineural hearing loss (SNHL) examined under 12 months. RESULTS Eight out of eleven children failed UNHS and were initially diagnosed as having bilateral nonsyndromic SNHL. Seven children underwent an audiological assessment before the age of 9 months. The earliest audiological examination was carried out at 1 and 3 months. The children with pathogenic variants in the USH2A gene in our examined group were identified in the first year of life via UNHS. The hearing threshold levels (HTL) for the USH2A group are compactly distributed between 51.25 dB and 66.25 dB, quartiles are 54 dB and 63.4 dB, with a median of 60 dB. The audiological profile of patients with biallelic USH2A mutations differs from audiograms of patients who had STRC-related hearing loss. We have not found any significant elevation in hearing thresholds in the first decade of life. We also estimated the prevalence of the USH2A and STRC mutations among GJB2-negative infants with bilateral nonsyndromic SNHL examined under 12 months, and it was 7.5% and 16.1%, respectively. CONCLUSION According to our results, the early hearing phenotype in pediatric patients with biallelic mutations in the USH2A- gene is characterized by nonsyndromic mild-to-moderate SNHL in the first decade of life. Our results indicate that the presence of mutations in the USH2A or STRC genes can be expected in a child with congenital mild-to-moderate nonsyndromic SNHL. This information is of practical importance for parents, as they have to know the prognosis of hearing loss for their child from the very beginning. Post-screening follow-up should include adequate clinical, genetic, and social support for children and their parents.
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Affiliation(s)
- T G Markova
- National Research Centre for Audiology and Hearing Rehabilitation, Moscow, 117513, Russia; Russian Medical Academy of Continuing Professional Education, Moscow, 125993, Russia
| | - M R Lalayants
- National Research Centre for Audiology and Hearing Rehabilitation, Moscow, 117513, Russia; Russian Medical Academy of Continuing Professional Education, Moscow, 125993, Russia
| | - N N Alekseeva
- National Research Centre for Audiology and Hearing Rehabilitation, Moscow, 117513, Russia; Russian Medical Academy of Continuing Professional Education, Moscow, 125993, Russia
| | - O P Ryzhkova
- Research Centre for Medical Genetics, Moscow, 115478, Russia
| | - O L Shatokhina
- Research Centre for Medical Genetics, Moscow, 115478, Russia
| | - N M Galeeva
- Research Centre for Medical Genetics, Moscow, 115478, Russia
| | - E A Bliznetz
- Research Centre for Medical Genetics, Moscow, 115478, Russia
| | - M E Weener
- CRO LLC «Oftalmic», Moscow, 125167, Russia
| | - O A Belov
- National Research Centre for Audiology and Hearing Rehabilitation, Moscow, 117513, Russia
| | - S S Chibisova
- National Research Centre for Audiology and Hearing Rehabilitation, Moscow, 117513, Russia; Russian Medical Academy of Continuing Professional Education, Moscow, 125993, Russia
| | - A V Polyakov
- Research Centre for Medical Genetics, Moscow, 115478, Russia
| | - G A Tavartkiladze
- National Research Centre for Audiology and Hearing Rehabilitation, Moscow, 117513, Russia; Russian Medical Academy of Continuing Professional Education, Moscow, 125993, Russia.
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Markova TG, Alekseeva NN, Belov OA, Chugunova TI, Tsygankova ER. [Hearing loss due to mutations in the genes responsible for Usher syndrome]. Vestn Otorinolaringol 2022; 87:52-59. [PMID: 35274893 DOI: 10.17116/otorino20228701152] [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] [Indexed: 06/14/2023]
Abstract
Usher syndrome is characterized by congenital bilateral sensorineural hearing loss and progressive retinitis pigmentosa, and has an autosomal recessive type of inheritance. The purpose of this work is to summarize the modern data of a clinical picture of Usher syndrome and analyse hearing impairment properties. The frequency of the syndrome among children suffering from hearing loss and deafness is from 3 to 10%. The prevalence of the syndrome in the world is estimated as 4.4 per 100.000 population. The complexity of the diagnosis of the syndrome lies in the significant clinical and genetic heterogeneity. Hearing and vision problems begin at different ages. Primary diagnosis begins with the clinical diagnosis of bilateral hearing loss and visual impairment manifests later. In this case the initial diagnosis of nonsyndromal hearing loss will not be definitive. Molecular genetic studies contribute to the early clinical diagnosis of the syndrome. Understanding the cause of the disease allows to conduct correct medical and genetic counseling and get closer to solving treatment problems.
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Affiliation(s)
- T G Markova
- National Research Centre for Audiology and Hearing Rehabilitation, Moscow, Russia
- Russian Medical Academy for Continuous Professional Education Audiology Department, Moscow, Russia
| | - N N Alekseeva
- National Research Centre for Audiology and Hearing Rehabilitation, Moscow, Russia
- Russian Medical Academy for Continuous Professional Education Audiology Department, Moscow, Russia
| | - O A Belov
- National Research Centre for Audiology and Hearing Rehabilitation, Moscow, Russia
| | - T I Chugunova
- National Research Centre for Audiology and Hearing Rehabilitation, Moscow, Russia
| | - E R Tsygankova
- National Research Centre for Audiology and Hearing Rehabilitation, Moscow, Russia
- Russian Medical Academy for Continuous Professional Education Audiology Department, Moscow, Russia
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Schneider N, Sundaresan Y, Gopalakrishnan P, Beryozkin A, Hanany M, Levanon EY, Banin E, Ben-Aroya S, Sharon D. Inherited retinal diseases: Linking genes, disease-causing variants, and relevant therapeutic modalities. Prog Retin Eye Res 2021; 89:101029. [PMID: 34839010 DOI: 10.1016/j.preteyeres.2021.101029] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 11/11/2021] [Accepted: 11/16/2021] [Indexed: 12/11/2022]
Abstract
Inherited retinal diseases (IRDs) are a clinically complex and heterogenous group of visual impairment phenotypes caused by pathogenic variants in at least 277 nuclear and mitochondrial genes, affecting different retinal regions, and depleting the vision of affected individuals. Genes that cause IRDs when mutated are unique by possessing differing genotype-phenotype correlations, varying inheritance patterns, hypomorphic alleles, and modifier genes thus complicating genetic interpretation. Next-generation sequencing has greatly advanced the identification of novel IRD-related genes and pathogenic variants in the last decade. For this review, we performed an in-depth literature search which allowed for compilation of the Global Retinal Inherited Disease (GRID) dataset containing 4,798 discrete variants and 17,299 alleles published in 31 papers, showing a wide range of frequencies and complexities among the 194 genes reported in GRID, with 65% of pathogenic variants being unique to a single individual. A better understanding of IRD-related gene distribution, gene complexity, and variant types allow for improved genetic testing and therapies. Current genetic therapeutic methods are also quite diverse and rely on variant identification, and range from whole gene replacement to single nucleotide editing at the DNA or RNA levels. IRDs and their suitable therapies thus require a range of effective disease modelling in human cells, granting insight into disease mechanisms and testing of possible treatments. This review summarizes genetic and therapeutic modalities of IRDs, provides new analyses of IRD-related genes (GRID and complexity scores), and provides information to match genetic-based therapies such as gene-specific and variant-specific therapies to the appropriate individuals.
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Affiliation(s)
- Nina Schneider
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, 91120, Israel
| | - Yogapriya Sundaresan
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, 91120, Israel
| | - Prakadeeswari Gopalakrishnan
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, 91120, Israel
| | - Avigail Beryozkin
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, 91120, Israel
| | - Mor Hanany
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, 91120, Israel
| | - Erez Y Levanon
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, 5290002, Israel
| | - Eyal Banin
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, 91120, Israel
| | - Shay Ben-Aroya
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, 5290002, Israel
| | - Dror Sharon
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, 91120, Israel.
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Zhou C, Xiao Y, Xie H, Liu S, Wang J. A novel USH2A variant in a patient with hearing loss and prenatal diagnosis of a familial fetus: a case report. BMC Med Genomics 2021; 14:200. [PMID: 34376197 PMCID: PMC8353764 DOI: 10.1186/s12920-021-01052-4] [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: 12/25/2020] [Accepted: 08/05/2021] [Indexed: 11/10/2022] Open
Abstract
Background Usher syndrome (USH) is the most common cause of inherited deaf-blindness. The current study aimed to identify pathogenic variants in a Chinese patient with hearing loss and to report the identification of a novel p.(Phe1583Leufs*10) variant in USH2A, which met the needs of prenatal diagnosis of the patient's mother. Case presentation Genomic DNA obtained from a five-year-old girl with hearing loss was analyzed via the hearing loss-targeted gene panels. We identified the compound heterozygous variants c.8559-2A>G and c.4749delT in Usher syndrome type 2A (USH2A) gene as the underlying cause of the patient; the former variation has been reported in the literature, but not the latter. The parents of the girl were heterozygous carriers. The two variants were classified as pathogenic. Based on these findings, amniotic fluid samples were used for prenatal diagnosis of the couple's fetus, which was found to carry c.4749delT but not c.8559-2A>G variation. During the follow-up period of more than 9 months after the birth of the fetus, it was confirmed that the infant was healthy. Conclusions The results of the present study identified two compound heterozygous USH2A variants in a patient with hearing loss and reported a novel USH2A variant which expands the spectrum of USH2A variants in USH. Supplementary Information The online version contains supplementary material available at 10.1186/s12920-021-01052-4.
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Affiliation(s)
- Cong Zhou
- Department of Obstetrics and Gynecology, West China Second University Hospital, Sichuan University, Prenatal Diagnosis Center of Sichuan Province, 20 Section 3 Renmin South Road, Chengdu, 610041, Sichuan, People's Republic of China.,Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, People's Republic of China
| | - Yuanyuan Xiao
- Department of Obstetrics and Gynecology, West China Second University Hospital, Sichuan University, Prenatal Diagnosis Center of Sichuan Province, 20 Section 3 Renmin South Road, Chengdu, 610041, Sichuan, People's Republic of China.,Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, People's Republic of China
| | - Hanbing Xie
- Department of Obstetrics and Gynecology, West China Second University Hospital, Sichuan University, Prenatal Diagnosis Center of Sichuan Province, 20 Section 3 Renmin South Road, Chengdu, 610041, Sichuan, People's Republic of China.,Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, People's Republic of China
| | - Shanling Liu
- Department of Obstetrics and Gynecology, West China Second University Hospital, Sichuan University, Prenatal Diagnosis Center of Sichuan Province, 20 Section 3 Renmin South Road, Chengdu, 610041, Sichuan, People's Republic of China. .,Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, People's Republic of China.
| | - Jing Wang
- Department of Obstetrics and Gynecology, West China Second University Hospital, Sichuan University, Prenatal Diagnosis Center of Sichuan Province, 20 Section 3 Renmin South Road, Chengdu, 610041, Sichuan, People's Republic of China. .,Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, People's Republic of China.
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8
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Meng X, Liu X, Li Y, Guo T, Yang L. Correlation between Genotype and Phenotype in 69 Chinese Patients with USH2A Mutations: A comparative study of the patients with Usher Syndrome and Nonsyndromic Retinitis Pigmentosa. Acta Ophthalmol 2021; 99:e447-e460. [PMID: 33124170 DOI: 10.1111/aos.14626] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 08/16/2020] [Accepted: 08/18/2020] [Indexed: 12/18/2022]
Abstract
PURPOSE The aim of this study was to analyse 69 Chinese patients with USH2A mutations and to assess the genotype-phenotype correlation. METHODS All 36 Usher syndrome type IIA patients and 33 nonsyndromic RP (retinitis pigmentosa) patients underwent clinical examinations. Eye examinations included best-corrected visual acuity, slit-lamp biomicroscopy, fundus examination with dilated pupils, fundus fluorescent angiography, visual field test, full-field electroretinography and optic coherence tomography; audiological assessment included pure tone audiometry and hearing thresholds. The molecular diagnosis of genotype combined the single-gene Sanger sequencing and next-generation sequencing. This study is a retrospective study. RESULTS The mean age of first symptoms with Usher syndrome type IIa and nonsyndromic RP patients was 13.7 versus 29.8 years (ocular phenotypes, p < 0.001); 17.7 versus 29.9 years (nyctalopia, p < 0.001); 44.7 versus 54.8 years (low vision based on VF, p < 0.001); 41.7 versus 54.7 years (low vision based on VA, p < 0.001); and 46.0 versus 56.7 years (legal blindness based on VF, p < 0.001). There was significant difference in variants in the two groups (p < 0.05). Among patients with mutation c.2802T > G (p.Cys934Trp), more (66.7%) presented with normal hearing. All patients (3/3, 100%) with the variant c.8232G > C (p.Trp2744Cys) had hearing loss. Furthermore, we identified 23 novel variants in USH2A. CONCLUSIONS Patients with Usher syndrome type IIa had an earlier onset of the disease, inferior visual function and presented with more truncating variants, compared with the nonsyndromic RP patients.
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Affiliation(s)
- Xiang Meng
- Department of Ophthalmology Peking University Third Hospital Beijing Key Laboratory of Restoration of Damaged Ocular Nerve Beijing China
| | - XiaoZhen Liu
- Department of Ophthalmology Peking University Third Hospital Beijing Key Laboratory of Restoration of Damaged Ocular Nerve Beijing China
| | - YingYing Li
- Department of Ophthalmology Peking University Third Hospital Beijing Key Laboratory of Restoration of Damaged Ocular Nerve Beijing China
| | - Tong Guo
- Department of Ophthalmology Peking University Third Hospital Beijing Key Laboratory of Restoration of Damaged Ocular Nerve Beijing China
| | - Liping Yang
- Department of Ophthalmology Peking University Third Hospital Beijing Key Laboratory of Restoration of Damaged Ocular Nerve Beijing China
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9
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Dulla K, Slijkerman R, van Diepen HC, Albert S, Dona M, Beumer W, Turunen JJ, Chan HL, Schulkens IA, Vorthoren L, den Besten C, Buil L, Schmidt I, Miao J, Venselaar H, Zang J, Neuhauss SCF, Peters T, Broekman S, Pennings R, Kremer H, Platenburg G, Adamson P, de Vrieze E, van Wijk E. Antisense oligonucleotide-based treatment of retinitis pigmentosa caused by USH2A exon 13 mutations. Mol Ther 2021; 29:2441-2455. [PMID: 33895329 PMCID: PMC8353187 DOI: 10.1016/j.ymthe.2021.04.024] [Citation(s) in RCA: 69] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 04/14/2021] [Accepted: 04/16/2021] [Indexed: 12/14/2022] Open
Abstract
Mutations in USH2A are among the most common causes of syndromic and non-syndromic retinitis pigmentosa (RP). The two most recurrent mutations in USH2A, c.2299delG and c.2276G > T, both reside in exon 13. Skipping exon 13 from the USH2A transcript presents a potential treatment modality in which the resulting transcript is predicted to encode a slightly shortened usherin protein. Morpholino-induced skipping of ush2a exon 13 in zebrafish ush2armc1 mutants resulted in the production of usherinΔexon 13 protein and a completely restored retinal function. Antisense oligonucleotides were investigated for their potential to selectively induce human USH2A exon 13 skipping. Lead candidate QR-421a induced a concentration-dependent exon 13 skipping in induced pluripotent stem cell (iPSC)-derived photoreceptor precursors from an Usher syndrome patient homozygous for the c.2299delG mutation. Mouse surrogate mQR-421a reached the retinal outer nuclear layer after a single intravitreal injection and induced a detectable level of exon skipping until at least 6 months post-injection. In conclusion, QR-421a-induced exon skipping proves to be a highly promising treatment option for RP caused by mutations in USH2A exon 13.
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Affiliation(s)
- Kalyan Dulla
- ProQR Therapeutics, Zernikedreef 9, 2333 CK Leiden, the Netherlands
| | - Ralph Slijkerman
- Department of Otorhinolaryngology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, the Netherlands
| | | | - Silvia Albert
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, the Netherlands
| | - Margo Dona
- Department of Otorhinolaryngology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, the Netherlands
| | - Wouter Beumer
- ProQR Therapeutics, Zernikedreef 9, 2333 CK Leiden, the Netherlands
| | - Janne J Turunen
- ProQR Therapeutics, Zernikedreef 9, 2333 CK Leiden, the Netherlands
| | - Hee Lam Chan
- ProQR Therapeutics, Zernikedreef 9, 2333 CK Leiden, the Netherlands
| | - Iris A Schulkens
- ProQR Therapeutics, Zernikedreef 9, 2333 CK Leiden, the Netherlands
| | - Lars Vorthoren
- ProQR Therapeutics, Zernikedreef 9, 2333 CK Leiden, the Netherlands
| | | | - Levi Buil
- ProQR Therapeutics, Zernikedreef 9, 2333 CK Leiden, the Netherlands
| | - Iris Schmidt
- ProQR Therapeutics, Zernikedreef 9, 2333 CK Leiden, the Netherlands
| | - Jiayi Miao
- ProQR Therapeutics, Zernikedreef 9, 2333 CK Leiden, the Netherlands
| | - Hanka Venselaar
- Center for Molecular and Biomolecular Informatics, Radboud University Medical Center, 6525 GA Nijmegen, the Netherlands
| | - Jingjing Zang
- University of Zürich, Institute of Molecular Life Sciences, 8057 Zürich, Switzerland
| | - Stephan C F Neuhauss
- University of Zürich, Institute of Molecular Life Sciences, 8057 Zürich, Switzerland
| | - Theo Peters
- Department of Otorhinolaryngology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, the Netherlands
| | - Sanne Broekman
- Department of Otorhinolaryngology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, the Netherlands
| | - Ronald Pennings
- Department of Otorhinolaryngology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, the Netherlands
| | - Hannie Kremer
- Department of Otorhinolaryngology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, the Netherlands; Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, the Netherlands
| | | | - Peter Adamson
- ProQR Therapeutics, Zernikedreef 9, 2333 CK Leiden, the Netherlands; UCL, Institute of Ophthalmology, 11-43 Bath Street, London EC1V 9EL, UK
| | - Erik de Vrieze
- Department of Otorhinolaryngology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, the Netherlands
| | - Erwin van Wijk
- Department of Otorhinolaryngology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, the Netherlands.
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10
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Panagiotou ES, Papathomas T, Nikopoulos K, Koukoula S, Quinodoz M, Rehman AU, Giannopoulos T, Rivolta C, Konstas AG. Management of Full-Thickness Macular Hole in A Genetically Confirmed Case with Usher Syndrome. Ophthalmol Ther 2020; 9:677-684. [PMID: 32566994 PMCID: PMC7406580 DOI: 10.1007/s40123-020-00276-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Indexed: 11/12/2022] Open
Abstract
INTRODUCTION Full-thickness macular hole (FTMH) formation is rarely seen in patients with retinitis pigmentosa (RP) and can have an adverse impact on their residual visual function. The underlying mechanisms are unknown, and clinical experience is limited regarding surgical outcomes. Here, we describe the surgical management of FTMH in a young patient with genetically confirmed Usher syndrome, the most common form of syndromic RP. CASE REPORT A 28-year-old woman presented with blurred vision in her right eye (RE). She had a history of RP and bilateral hearing impairment since childhood. Fundoscopy and spectral-domain optical coherence tomography revealed a FTMH in the RE along with typical RP features bilaterally. After pars plana vitrectomy (PPV) with internal limiting membrane peel and gas tamponade, the FTMH closed. Six months after PPV the patient underwent cataract surgery in the affected eye, and the visual acuity remained stable compared to baseline. The clinical diagnosis of Usher syndrome was genetically confirmed by whole exome sequencing (WES), which revealed the presence of two pathogenic nucleotide variants in trans (compound heterozygosity) in the gene USH2A. CONCLUSION We report a rare case of successful closure of a FTMH in a patient with Usher syndrome. Surgical treatment of FTMH can help preserve the central vision in RP patients, whose peripheral vision is severely affected.
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Affiliation(s)
- Evangelia S Panagiotou
- 1st Department of Ophthalmology, Aristotle University of Thessaloniki, AHEPA Hospital, Thessaloniki, Greece
| | - Thomas Papathomas
- 1st Department of Ophthalmology, Aristotle University of Thessaloniki, AHEPA Hospital, Thessaloniki, Greece
| | - Konstantinos Nikopoulos
- Laboratory of Oncogenomics, Department of Hematology, Lausanne University Hospital (CHUV), Lausanne, Switzerland
| | | | - Mathieu Quinodoz
- Department of Genetics and Genome Biology, University of Leicester, Leicester, UK
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), Basel, Switzerland
- Department of Ophthalmology, University of Basel, Basel, Switzerland
| | - Atta Ur Rehman
- Division of Genetic Medicine, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Theodoros Giannopoulos
- 1st Department of Ophthalmology, Aristotle University of Thessaloniki, AHEPA Hospital, Thessaloniki, Greece
| | - Carlo Rivolta
- Department of Genetics and Genome Biology, University of Leicester, Leicester, UK
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), Basel, Switzerland
- Department of Ophthalmology, University of Basel, Basel, Switzerland
| | - Anastasios G Konstas
- 1st Department of Ophthalmology, Aristotle University of Thessaloniki, AHEPA Hospital, Thessaloniki, Greece.
- 3rd Department of Ophthalmology, Aristotle University of Thessaloniki, AHEPA Hospital, Thessaloniki, Greece.
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11
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Yu D, Zou J, Chen Q, Zhu T, Sui R, Yang J. Structural modeling, mutation analysis, and in vitro expression of usherin, a major protein in inherited retinal degeneration and hearing loss. Comput Struct Biotechnol J 2020; 18:1363-1382. [PMID: 32637036 PMCID: PMC7317166 DOI: 10.1016/j.csbj.2020.05.025] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 05/26/2020] [Accepted: 05/28/2020] [Indexed: 11/15/2022] Open
Abstract
Usherin is the most common causative protein associated with autosomal recessive retinitis pigmentosa (RP) and Usher syndrome (USH), which are characterized by retinal degeneration alone and in combination with hearing loss, respectively. Usherin is essential for photoreceptor survival and hair cell bundle integrity. However, the molecular mechanism underlying usherin function in normal and disease conditions is unclear. In this study, we investigated structural models of usherin domains and localization of usherin pathogenic small in-frame mutations, mainly homozygous missense mutations. We found that usherin fibronectin III (FN3) domains and most laminin-related domains have a β-sandwich structure. Some FN3 domains are predicted to interact with each other and with laminin-related domains. The usherin protein may bend at some FN3 linker regions. RP- and USH-associated small in-frame mutations are differentially located in usherin domains. Most of them are located at the periphery of β-sandwiches, with some at the interface between interacting domains. The usherin laminin epidermal growth factor repeats adopt a rod-shaped structure, which is maintained by disulfide bonds. Most missense mutations and deletion of exon 13 in this region disrupt the disulfide bonds and may affect local protein folding. Despite low expression of the recombinant entire protein and protein fragments in mammalian cell culture, usherin FN3 fragments are more robustly expressed and secreted than its laminin-related fragments. Our findings provide new insights into the usherin structure and the disease mechanisms caused by pathogenic small in-frame mutations, which will help inform future experimental research on diagnosis, disease mechanisms, and therapeutic approaches.
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Key Words
- Cell adhesion
- DCC, deleted in colorectal cancer
- FN3, fibronectin III
- GMQE, global quality estimation score
- HGMD, Human Gene Mutation Database
- Hair cell
- I-TASSER, Iterative Threading ASSEmbly Refinement
- LE, laminin EGF
- LG, laminin globular
- LGL, laminin globular-like
- LN, laminin N-terminal
- Membrane protein
- NCBI, National Center for Biotechnology Information
- Photoreceptor
- Protein folding
- QMEAN, qualitative model energy analysis score
- QSQE, Quaternary Structure Quality Estimation
- RMSD, root mean square deviation
- RP, retinitis pigmentosa
- Recombinant protein expression
- Retinitis pigmentosa
- SMTL, SWISS-MODEL template library
- Structural model
- TM-score, template modeling score
- USH, Usher syndrome
- Usher syndrome
- hFc, human Fc fragment
- mFc, mouse Fc fragment
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Affiliation(s)
- Dongmei Yu
- Department of Ophthalmology and Visual Sciences, Moran Eye Center, University of Utah, Salt Lake City, UT, United States
| | - Junhuang Zou
- Department of Ophthalmology and Visual Sciences, Moran Eye Center, University of Utah, Salt Lake City, UT, United States
| | - Qian Chen
- Department of Ophthalmology and Visual Sciences, Moran Eye Center, University of Utah, Salt Lake City, UT, United States
| | - Tian Zhu
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Ruifang Sui
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Jun Yang
- Department of Ophthalmology and Visual Sciences, Moran Eye Center, University of Utah, Salt Lake City, UT, United States
- Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, UT, United States
- Division of Otolaryngology, Department of Surgery, University of Utah, Salt Lake City, UT, United States
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12
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Nolen RM, Hufnagel RB, Friedman TB, Turriff AE, Brewer CC, Zalewski CK, King KA, Wafa TT, Griffith AJ, Brooks BP, Zein WM. Atypical and ultra-rare Usher syndrome: a review. Ophthalmic Genet 2020; 41:401-412. [PMID: 32372680 DOI: 10.1080/13816810.2020.1747090] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Usher syndrome has classically been described as a combination of hearing loss and rod-cone dystrophy; vestibular dysfunction is present in many patients. Three distinct clinical subtypes were documented in the late 1970s. Genotyping efforts have led to the identification of several genes associated with the disease. Recent literature has seen multiple publications referring to "atypical" Usher syndrome presentations. This manuscript reviews the molecular etiology of Usher syndrome, highlighting rare presentations and molecular causes. Reports of "atypical" disease are summarized noting the wide discrepancy in the spectrum of phenotypic deviations from the classical presentation. Guidelines for establishing a clear nomenclature system are suggested.
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Affiliation(s)
- Rosalie M Nolen
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health , Bethesda, MD, USA
| | - Robert B Hufnagel
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health , Bethesda, MD, USA
| | - Thomas B Friedman
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health , Bethesda, MD, USA
| | - Amy E Turriff
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health , Bethesda, MD, USA
| | - Carmen C Brewer
- Otolaryngology Branch, National Institute of Deafness and Other Communication Disorders, National Institutes of Health , Bethesda, MD, USA
| | - Christopher K Zalewski
- Otolaryngology Branch, National Institute of Deafness and Other Communication Disorders, National Institutes of Health , Bethesda, MD, USA
| | - Kelly A King
- Otolaryngology Branch, National Institute of Deafness and Other Communication Disorders, National Institutes of Health , Bethesda, MD, USA
| | - Talah T Wafa
- Otolaryngology Branch, National Institute of Deafness and Other Communication Disorders, National Institutes of Health , Bethesda, MD, USA
| | - Andrew J Griffith
- Otolaryngology Branch, National Institute of Deafness and Other Communication Disorders, National Institutes of Health , Bethesda, MD, USA
| | - Brian P Brooks
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health , Bethesda, MD, USA
| | - Wadih M Zein
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health , Bethesda, MD, USA
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13
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Karali M, Testa F, Brunetti-Pierri R, Di Iorio V, Pizzo M, Melillo P, Barillari MR, Torella A, Musacchia F, D’Angelo L, Banfi S, Simonelli F. Clinical and Genetic Analysis of a European Cohort with Pericentral Retinitis Pigmentosa. Int J Mol Sci 2019; 21:ijms21010086. [PMID: 31877679 PMCID: PMC6982348 DOI: 10.3390/ijms21010086] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 12/12/2019] [Accepted: 12/19/2019] [Indexed: 12/28/2022] Open
Abstract
Retinitis pigmentosa (RP) is a clinically heterogenous disease that comprises a wide range of phenotypic and genetic subtypes. Pericentral RP is an atypical form of RP characterized by bone-spicule pigmentation and/or atrophy confined in the near mid-periphery of the retina. In contrast to classic RP, the far periphery is better preserved in pericentral RP. The aim of this study was to perform the first detailed clinical and genetic analysis of a cohort of European subjects with pericentral RP to determine the phenotypic features and the genetic bases of the disease. A total of 54 subjects from 48 independent families with pericentral RP, non-syndromic and syndromic, were evaluated through a full ophthalmological examination and underwent clinical exome or retinopathy gene panel sequencing. Disease-causative variants were identified in 22 of the 35 families (63%) in 10 different genes, four of which are also responsible for syndromic RP. Thirteen of the 34 likely pathogenic variants were novel. Intra-familiar variability was also observed. The current study confirms the mild phenotype of pericentral RP and extends the spectrum of genes associated with this condition.
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Affiliation(s)
- Marianthi Karali
- Medical Genetics, Department of Precision Medicine, Università degli Studi della Campania ‘Luigi Vanvitelli’, via Luigi De Crecchio 7, 80138 Naples, Italy; (M.K.); (A.T.)
- Telethon Institute of Genetics and Medicine, via Campi Flegrei 34, 80078 Pozzuoli, Italy; (M.P.); (F.M.)
| | - Francesco Testa
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Università degli Studi della Campania ‘Luigi Vanvitelli’, via Pansini 5, 80131 Naples, Italy; (F.T.); (R.B.-P.); (V.D.I.); (P.M.); (M.R.B.); (L.D.A.)
| | - Raffaella Brunetti-Pierri
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Università degli Studi della Campania ‘Luigi Vanvitelli’, via Pansini 5, 80131 Naples, Italy; (F.T.); (R.B.-P.); (V.D.I.); (P.M.); (M.R.B.); (L.D.A.)
| | - Valentina Di Iorio
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Università degli Studi della Campania ‘Luigi Vanvitelli’, via Pansini 5, 80131 Naples, Italy; (F.T.); (R.B.-P.); (V.D.I.); (P.M.); (M.R.B.); (L.D.A.)
| | - Mariateresa Pizzo
- Telethon Institute of Genetics and Medicine, via Campi Flegrei 34, 80078 Pozzuoli, Italy; (M.P.); (F.M.)
| | - Paolo Melillo
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Università degli Studi della Campania ‘Luigi Vanvitelli’, via Pansini 5, 80131 Naples, Italy; (F.T.); (R.B.-P.); (V.D.I.); (P.M.); (M.R.B.); (L.D.A.)
| | - Maria Rosaria Barillari
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Università degli Studi della Campania ‘Luigi Vanvitelli’, via Pansini 5, 80131 Naples, Italy; (F.T.); (R.B.-P.); (V.D.I.); (P.M.); (M.R.B.); (L.D.A.)
| | - Annalaura Torella
- Medical Genetics, Department of Precision Medicine, Università degli Studi della Campania ‘Luigi Vanvitelli’, via Luigi De Crecchio 7, 80138 Naples, Italy; (M.K.); (A.T.)
| | - Francesco Musacchia
- Telethon Institute of Genetics and Medicine, via Campi Flegrei 34, 80078 Pozzuoli, Italy; (M.P.); (F.M.)
| | - Luigi D’Angelo
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Università degli Studi della Campania ‘Luigi Vanvitelli’, via Pansini 5, 80131 Naples, Italy; (F.T.); (R.B.-P.); (V.D.I.); (P.M.); (M.R.B.); (L.D.A.)
| | - Sandro Banfi
- Medical Genetics, Department of Precision Medicine, Università degli Studi della Campania ‘Luigi Vanvitelli’, via Luigi De Crecchio 7, 80138 Naples, Italy; (M.K.); (A.T.)
- Telethon Institute of Genetics and Medicine, via Campi Flegrei 34, 80078 Pozzuoli, Italy; (M.P.); (F.M.)
- Correspondence: (S.B.); (F.S.); Tel.: +39-081-19230628 (S.B.); +39-081-7704501 (F.S.)
| | - Francesca Simonelli
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Università degli Studi della Campania ‘Luigi Vanvitelli’, via Pansini 5, 80131 Naples, Italy; (F.T.); (R.B.-P.); (V.D.I.); (P.M.); (M.R.B.); (L.D.A.)
- Correspondence: (S.B.); (F.S.); Tel.: +39-081-19230628 (S.B.); +39-081-7704501 (F.S.)
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14
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Sanjurjo-Soriano C, Erkilic N, Baux D, Mamaeva D, Hamel CP, Meunier I, Roux AF, Kalatzis V. Genome Editing in Patient iPSCs Corrects the Most Prevalent USH2A Mutations and Reveals Intriguing Mutant mRNA Expression Profiles. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2019; 17:156-173. [PMID: 31909088 PMCID: PMC6938853 DOI: 10.1016/j.omtm.2019.11.016] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 11/15/2019] [Indexed: 12/13/2022]
Abstract
Inherited retinal dystrophies (IRDs) are characterized by progressive photoreceptor degeneration and vision loss. Usher syndrome (USH) is a syndromic IRD characterized by retinitis pigmentosa (RP) and hearing loss. USH is clinically and genetically heterogeneous, and the most prevalent causative gene is USH2A. USH2A mutations also account for a large number of isolated autosomal recessive RP (arRP) cases. This high prevalence is due to two recurrent USH2A mutations, c.2276G>T and c.2299delG. Due to the large size of the USH2A cDNA, gene augmentation therapy is inaccessible. However, CRISPR/Cas9-mediated genome editing is a viable alternative. We used enhanced specificity Cas9 of Streptococcus pyogenes (eSpCas9) to successfully achieve seamless correction of the two most prevalent USH2A mutations in induced pluripotent stem cells (iPSCs) of patients with USH or arRP. Our results highlight features that promote high target efficacy and specificity of eSpCas9. Consistently, we did not identify any off-target mutagenesis in the corrected iPSCs, which also retained pluripotency and genetic stability. Furthermore, analysis of USH2A expression unexpectedly identified aberrant mRNA levels associated with the c.2276G>T and c.2299delG mutations that were reverted following correction. Taken together, our efficient CRISPR/Cas9-mediated strategy for USH2A mutation correction brings hope for a potential treatment for USH and arRP patients.
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Affiliation(s)
- Carla Sanjurjo-Soriano
- Inserm U1051, Institute for Neurosciences of Montpellier, 34091 Montpellier, France.,University of Montpellier, 34095 Montpellier, France
| | - Nejla Erkilic
- Inserm U1051, Institute for Neurosciences of Montpellier, 34091 Montpellier, France.,University of Montpellier, 34095 Montpellier, France
| | - David Baux
- University of Montpellier, 34095 Montpellier, France.,Medical Genetics Laboratory, CHU, 34093 Montpellier, France
| | - Daria Mamaeva
- Inserm U1051, Institute for Neurosciences of Montpellier, 34091 Montpellier, France.,University of Montpellier, 34095 Montpellier, France
| | - Christian P Hamel
- Inserm U1051, Institute for Neurosciences of Montpellier, 34091 Montpellier, France.,University of Montpellier, 34095 Montpellier, France.,National Reference Centre for Inherited Sensory Disorders, CHU, 34295 Montpellier, France
| | - Isabelle Meunier
- Inserm U1051, Institute for Neurosciences of Montpellier, 34091 Montpellier, France.,University of Montpellier, 34095 Montpellier, France.,National Reference Centre for Inherited Sensory Disorders, CHU, 34295 Montpellier, France
| | - Anne-Françoise Roux
- University of Montpellier, 34095 Montpellier, France.,Medical Genetics Laboratory, CHU, 34093 Montpellier, France
| | - Vasiliki Kalatzis
- Inserm U1051, Institute for Neurosciences of Montpellier, 34091 Montpellier, France.,University of Montpellier, 34095 Montpellier, France
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15
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Wan L, Deng B, Wu Z, Chen X. Exome sequencing study of 20 patients with high myopia. PeerJ 2018; 6:e5552. [PMID: 30245926 PMCID: PMC6148412 DOI: 10.7717/peerj.5552] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2018] [Accepted: 08/07/2018] [Indexed: 02/05/2023] Open
Abstract
Background High myopia is a common ocular disease worldwide. To expand our current understanding of the genetic basis of high myopia, we carried out a whole exome sequencing (WES) study to identify potential causal gene mutations. Methods A total of 20 individuals with high myopia were exome sequenced. A novel filtering strategy combining phenotypes and functional impact of variants was applied to identify candidate genes by multi-step bioinformatics analyses. Network and enrichment analysis were employed to examine the biological pathways involved in the candidate genes. Results In 16 out of 20 patients, we identified 20 potential pathogenic gene variants for high myopia. A total of 18 variants were located in myopia-associated chromosomal regions. In addition to the novel mutations found in five known myopia genes (ADAMTS18, CSMD1, P3H2, RPGR, and SLC39A5), we also identified pathogenic variants in seven ocular disease genes (ABCA4, CEP290, HSPG2, PCDH15, SAG, SEMA4A, and USH2A) as novel candidate genes. The biological processes associated with vision were significantly enriched in our candidate genes, including visual perception, photoreceptor cell maintenance, retinoid metabolic process, and cellular response to zinc ion starvation. Discussion Systematic mutation analysis of candidate genes was performed using WES data, functional interaction (FI) network, Gene Ontology and pathway enrichment. FI network analysis revealed important network modules and regulator linker genes (EP300, CTNNB1) potentially related to high myopia development. Our study expanded the list of candidate genes associated with high myopia, which increased the genetic screening performance and provided implications for future studies on the molecular genetics of myopia.
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Affiliation(s)
- Ling Wan
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, Sichuan, China.,Department of Ophthalmology, Sichuan Academy of Medical Sciences, Sichuan Provincial People's Hospital and Affiliated Hospital of University of Electronic Science and Technology, Chengdu, Sichuan, China
| | - Boling Deng
- Department of Ophthalmology, Sichuan Academy of Medical Sciences, Sichuan Provincial People's Hospital and Affiliated Hospital of University of Electronic Science and Technology, Chengdu, Sichuan, China
| | - Zhengzheng Wu
- Department of Ophthalmology, Sichuan Academy of Medical Sciences, Sichuan Provincial People's Hospital and Affiliated Hospital of University of Electronic Science and Technology, Chengdu, Sichuan, China
| | - Xiaoming Chen
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, Sichuan, China
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16
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Huang L, Mao Y, Yang J, Li Y, Li Y, Yang Z. Mutation screening of the USH2A gene in retinitis pigmentosa and USHER patients in a Han Chinese population. Eye (Lond) 2018; 32:1608-1614. [PMID: 29899460 PMCID: PMC6189035 DOI: 10.1038/s41433-018-0130-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 01/01/2018] [Accepted: 04/25/2018] [Indexed: 02/08/2023] Open
Abstract
Objectives USH2A encodes for usherin, a basement membrane protein in the inner ear and retina. USH2A can cause retinitis pigmentosa (RP) with or without hearing loss. The aim of this study was to detect USH2A mutations in a Chinese cohort of 75 small RP families and 10 Usher syndrome families. Methods We performed a direct Sanger sequencing analysis of the USH2A gene to identify mutations for this cohort. Results We identified a total of eight mutations in four of the 75 small RP families (5.3%) and two mutations in one of the 10 Usher families (10%); all families were detected to have compound heterozygous mutations. In families with nonsyndromic RP, we identified the compound heterozygous mutations p.Pro4818Leuand p.Leu2395Hisfs*19 in family No. 19114, p.Arg4493His and p.His1677Glnfs*15 in family No.19162, c.8559-2A > G and p.Arg1549* in family No.19123 and p.Ser5060Pro and p.Arg34Leufs*41 in family No.19178. We also identified the heterozygous mutations p.Arg3719His and p.Cys934Trp in family No.19124, which was the Usher syndrome family. These mutations were predicted to be harmful by SIFT, PROVEAN, Mutation Taster or PolyPhen-2. Conclusions Our results revealed six novel mutations in the USH2A gene in a Chinese population, which is beneficial for the clinical use of genetic testing of USH2A in patients with autosomal-recessive or sporadic RP and Usher syndrome.
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Affiliation(s)
- Lulin Huang
- Sichuan Provincial Key Laboratory for Human Disease Gene Study and the Department of Laboratory Medicine and School of Medicine, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, 32 the First Ring Road West 2, Chengdu, Sichuan, 610072, China. .,Institute of Chengdu Biology, and Sichuan Translational Medicine Hospital, Chinese Academy of Sciences, Chengdu, Sichuan, China. .,Center of Information in Biomedicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China.
| | - Yao Mao
- Sichuan Provincial Key Laboratory for Human Disease Gene Study and the Department of Laboratory Medicine and School of Medicine, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, 32 the First Ring Road West 2, Chengdu, Sichuan, 610072, China
| | - Jiyun Yang
- Sichuan Provincial Key Laboratory for Human Disease Gene Study and the Department of Laboratory Medicine and School of Medicine, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, 32 the First Ring Road West 2, Chengdu, Sichuan, 610072, China
| | - Yuanfeng Li
- Sichuan Provincial Key Laboratory for Human Disease Gene Study and the Department of Laboratory Medicine and School of Medicine, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, 32 the First Ring Road West 2, Chengdu, Sichuan, 610072, China
| | - Yang Li
- Department of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Zhenglin Yang
- Sichuan Provincial Key Laboratory for Human Disease Gene Study and the Department of Laboratory Medicine and School of Medicine, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, 32 the First Ring Road West 2, Chengdu, Sichuan, 610072, China. .,Institute of Chengdu Biology, and Sichuan Translational Medicine Hospital, Chinese Academy of Sciences, Chengdu, Sichuan, China. .,Center of Information in Biomedicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China.
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17
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Dona M, Slijkerman R, Lerner K, Broekman S, Wegner J, Howat T, Peters T, Hetterschijt L, Boon N, de Vrieze E, Sorusch N, Wolfrum U, Kremer H, Neuhauss S, Zang J, Kamermans M, Westerfield M, Phillips J, van Wijk E. Usherin defects lead to early-onset retinal dysfunction in zebrafish. Exp Eye Res 2018; 173:148-159. [PMID: 29777677 DOI: 10.1016/j.exer.2018.05.015] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 05/15/2018] [Accepted: 05/15/2018] [Indexed: 01/24/2023]
Abstract
Mutations in USH2A are the most frequent cause of Usher syndrome and autosomal recessive nonsyndromic retinitis pigmentosa. To unravel the pathogenic mechanisms underlying USH2A-associated retinal degeneration and to evaluate future therapeutic strategies that could potentially halt the progression of this devastating disorder, an animal model is needed. The available Ush2a knock-out mouse model does not mimic the human phenotype, because it presents with only a mild and late-onset retinal degeneration. Using CRISPR/Cas9-technology, we introduced protein-truncating germline lesions into the zebrafish ush2a gene (ush2armc1: c.2337_2342delinsAC; p.Cys780GlnfsTer32 and ush2ab1245: c.15520_15523delinsTG; p.Ala5174fsTer). Homozygous mutants were viable and displayed no obvious morphological or developmental defects. Immunohistochemical analyses with antibodies recognizing the N- or C-terminal region of the ush2a-encoded protein, usherin, demonstrated complete absence of usherin in photoreceptors of ush2armc1, but presence of the ectodomain of usherin at the periciliary membrane of ush2ab1245-derived photoreceptors. Furthermore, defects of usherin led to a reduction in localization of USH2 complex members, whirlin and Adgrv1, at the photoreceptor periciliary membrane of both mutants. Significantly elevated levels of apoptotic photoreceptors could be observed in both mutants when kept under constant bright illumination for three days. Electroretinogram (ERG) recordings revealed a significant and similar decrease in both a- and b-wave amplitudes in ush2armc1 as well as ush2ab1245 larvae as compared to strain- and age-matched wild-type larvae. In conclusion, this study shows that mutant ush2a zebrafish models present with early-onset retinal dysfunction that is exacerbated by light exposure. These models provide a better understanding of the pathophysiology underlying USH2A-associated RP and a unique opportunity to evaluate future therapeutic strategies.
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Affiliation(s)
- Margo Dona
- Department of Otorhinolaryngology, Radboud University Medical Center, Geert Grooteplein 10, 6525 GA Nijmegen, The Netherlands; Radboud Institute for Molecular Life Sciences, Geert Grooteplein Zuid 28, 6525 GA Nijmegen, The Netherlands
| | - Ralph Slijkerman
- Department of Otorhinolaryngology, Radboud University Medical Center, Geert Grooteplein 10, 6525 GA Nijmegen, The Netherlands; Radboud Institute for Molecular Life Sciences, Geert Grooteplein Zuid 28, 6525 GA Nijmegen, The Netherlands
| | - Kimberly Lerner
- Institute of Neuroscience, 1254 University of Oregon, Eugene, OR, 97403-1254, USA
| | - Sanne Broekman
- Department of Human Genetics, Radboud University Medical Center, Geert Grooteplein 10, 6525 GA Nijmegen, The Netherlands; Donders Institute for Brain, Cognition, and Behavior, Montessorilaan 3, 6525 HR Nijmegen, The Netherlands
| | - Jeremy Wegner
- Institute of Neuroscience, 1254 University of Oregon, Eugene, OR, 97403-1254, USA
| | - Taylor Howat
- Institute of Neuroscience, 1254 University of Oregon, Eugene, OR, 97403-1254, USA
| | - Theo Peters
- Institute of Neuroscience, 1254 University of Oregon, Eugene, OR, 97403-1254, USA; Donders Institute for Brain, Cognition, and Behavior, Montessorilaan 3, 6525 HR Nijmegen, The Netherlands
| | - Lisette Hetterschijt
- Department of Otorhinolaryngology, Radboud University Medical Center, Geert Grooteplein 10, 6525 GA Nijmegen, The Netherlands; Donders Institute for Brain, Cognition, and Behavior, Montessorilaan 3, 6525 HR Nijmegen, The Netherlands
| | - Nanda Boon
- Department of Human Genetics, Radboud University Medical Center, Geert Grooteplein 10, 6525 GA Nijmegen, The Netherlands
| | - Erik de Vrieze
- Department of Otorhinolaryngology, Radboud University Medical Center, Geert Grooteplein 10, 6525 GA Nijmegen, The Netherlands; Donders Institute for Brain, Cognition, and Behavior, Montessorilaan 3, 6525 HR Nijmegen, The Netherlands
| | - Nasrin Sorusch
- Institute of Molecular Physiology, Johannes Gutenberg University, Johannes-von-Muellerweg 6, D-55099 Mainz, Germany
| | - Uwe Wolfrum
- Institute of Molecular Physiology, Johannes Gutenberg University, Johannes-von-Muellerweg 6, D-55099 Mainz, Germany
| | - Hannie Kremer
- Department of Otorhinolaryngology, Radboud University Medical Center, Geert Grooteplein 10, 6525 GA Nijmegen, The Netherlands; Department of Human Genetics, Radboud University Medical Center, Geert Grooteplein 10, 6525 GA Nijmegen, The Netherlands; Donders Institute for Brain, Cognition, and Behavior, Montessorilaan 3, 6525 HR Nijmegen, The Netherlands
| | - Stephan Neuhauss
- University of Zürich, Institute of Molecular Life Sciences, Winterthurerstrasse 190, Zürich, CH - 8057, Switzerland
| | - Jingjing Zang
- University of Zürich, Institute of Molecular Life Sciences, Winterthurerstrasse 190, Zürich, CH - 8057, Switzerland
| | - Maarten Kamermans
- Retinal Signal Processing Lab, Netherlands Institute for Neuroscience, Meibergdreef 47, 1105 BA Amsterdam, The Netherlands; Department of Biomedical Physics, Academisch Medisch Centrum, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands
| | - Monte Westerfield
- Institute of Neuroscience, 1254 University of Oregon, Eugene, OR, 97403-1254, USA
| | - Jennifer Phillips
- Institute of Neuroscience, 1254 University of Oregon, Eugene, OR, 97403-1254, USA
| | - Erwin van Wijk
- Department of Otorhinolaryngology, Radboud University Medical Center, Geert Grooteplein 10, 6525 GA Nijmegen, The Netherlands; Donders Institute for Brain, Cognition, and Behavior, Montessorilaan 3, 6525 HR Nijmegen, The Netherlands.
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18
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Neuhaus C, Eisenberger T, Decker C, Nagl S, Blank C, Pfister M, Kennerknecht I, Müller-Hofstede C, Charbel Issa P, Heller R, Beck B, Rüther K, Mitter D, Rohrschneider K, Steinhauer U, Korbmacher HM, Huhle D, Elsayed SM, Taha HM, Baig SM, Stöhr H, Preising M, Markus S, Moeller F, Lorenz B, Nagel-Wolfrum K, Khan AO, Bolz HJ. Next-generation sequencing reveals the mutational landscape of clinically diagnosed Usher syndrome: copy number variations, phenocopies, a predominant target for translational read-through, and PEX26 mutated in Heimler syndrome. Mol Genet Genomic Med 2017; 5:531-552. [PMID: 28944237 PMCID: PMC5606877 DOI: 10.1002/mgg3.312] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 06/06/2017] [Accepted: 06/09/2017] [Indexed: 12/23/2022] Open
Abstract
Background Combined retinal degeneration and sensorineural hearing impairment is mostly due to autosomal recessive Usher syndrome (USH1: congenital deafness, early retinitis pigmentosa (RP); USH2: progressive hearing impairment, RP). Methods Sanger sequencing and NGS of 112 genes (Usher syndrome, nonsyndromic deafness, overlapping conditions), MLPA, and array‐CGH were conducted in 138 patients clinically diagnosed with Usher syndrome. Results A molecular diagnosis was achieved in 97% of both USH1 and USH2 patients, with biallelic mutations in 97% (USH1) and 90% (USH2), respectively. Quantitative readout reliably detected CNVs (confirmed by MLPA or array‐CGH), qualifying targeted NGS as one tool for detecting point mutations and CNVs. CNVs accounted for 10% of identified USH2A alleles, often in trans to seemingly monoallelic point mutations. We demonstrate PTC124‐induced read‐through of the common p.Trp3955* nonsense mutation (13% of detected USH2A alleles), a potential therapy target. Usher gene mutations were found in most patients with atypical Usher syndrome, but the diagnosis was adjusted in case of double homozygosity for mutations in OTOA and NR2E3, genes implicated in isolated deafness and RP. Two patients with additional enamel dysplasia had biallelic PEX26 mutations, for the first time linking this gene to Heimler syndrome. Conclusion Targeted NGS not restricted to Usher genes proved beneficial in uncovering conditions mimicking Usher syndrome.
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Affiliation(s)
| | | | | | - Sandra Nagl
- Bioscientia Center for Human GeneticsIngelheimGermany
| | | | - Markus Pfister
- HNO-Praxis SarnenSarnenSwitzerland.,Molecular Genetics, THRCDepartment of OtolaryngologyUniversity of TübingenTübingenGermany
| | - Ingo Kennerknecht
- Institute of Human GeneticsWestfälische Wilhelms-UniversitätMünsterGermany
| | | | - Peter Charbel Issa
- Department of OphthalmologyUniversity of BonnBonnGermany.,Center for Rare Diseases Bonn (ZSEB)University of BonnBonnGermany.,Oxford Eye HospitalUniversity of OxfordOxfordUK
| | - Raoul Heller
- Institute of Human GeneticsUniversity Hospital of CologneCologneGermany
| | - Bodo Beck
- Institute of Human GeneticsUniversity Hospital of CologneCologneGermany
| | | | - Diana Mitter
- Institute of Human GeneticsUniversity of Leipzig Hospitals and ClinicsLeipzigGermany
| | | | | | - Heike M Korbmacher
- Department of OrthodonticsGiessen and Marburg University Hospital, Marburg CampusMarburgGermany
| | | | - Solaf M Elsayed
- Medical Genetics CenterCairoEgypt.,Children's HospitalAin Shams UniversityCairoEgypt
| | | | - Shahid M Baig
- Human Molecular Genetics LaboratoryHealth Biotechnology DivisionNational Institute for Biotechnology and Genetic Engineering (NIBGE)FaisalabadPakistan
| | - Heidi Stöhr
- Department of Human GeneticsUniversity Medical Center RegensburgRegensburgGermany
| | - Markus Preising
- Department of OphthalmologyJustus-Liebig-University GiessenGiessenGermany
| | | | - Fabian Moeller
- Department of Cell and Matrix BiologyInstitute of Zoology, Johannes GutenbergUniversity of MainzMainzGermany
| | - Birgit Lorenz
- Department of OphthalmologyJustus-Liebig-University GiessenGiessenGermany
| | - Kerstin Nagel-Wolfrum
- Department of Cell and Matrix BiologyInstitute of Zoology, Johannes GutenbergUniversity of MainzMainzGermany
| | - Arif O Khan
- Division of Pediatric OphthalmologyKing Khaled Eye Specialist HospitalRiyadhSaudi Arabia.,Eye InstituteCleveland ClinicAbu DhabiUAE
| | - Hanno J Bolz
- Bioscientia Center for Human GeneticsIngelheimGermany.,Institute of Human GeneticsUniversity Hospital of CologneCologneGermany
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19
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Hartel BP, Agterberg MJH, Snik AF, Kunst HPM, van Opstal AJ, Bosman AJ, Pennings RJE. Hearing aid fitting for visual and hearing impaired patients with Usher syndrome type IIa. Clin Otolaryngol 2016; 42:805-814. [PMID: 27759911 PMCID: PMC5516239 DOI: 10.1111/coa.12775] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/16/2016] [Indexed: 11/28/2022]
Abstract
OBJECTIVES Usher syndrome is the leading cause of hereditary deaf-blindness. Most patients with Usher syndrome type IIa start using hearing aids from a young age. A serious complaint refers to interference between sound localisation abilities and adaptive sound processing (compression), as present in today's hearing aids. The aim of this study was to investigate the effect of advanced signal processing on binaural hearing, including sound localisation. DESIGN AND PARTICIPANTS In this prospective study, patients were fitted with hearing aids with a nonlinear (compression) and linear amplification programs. Data logging was used to objectively evaluate the use of either program. Performance was evaluated with a speech-in-noise test, a sound localisation test and two questionnaires focussing on self-reported benefit. RESULTS Data logging confirmed that the reported use of hearing aids was high. The linear program was used significantly more often (average use: 77%) than the nonlinear program (average use: 17%). The results for speech intelligibility in noise and sound localisation did not show a significant difference between type of amplification. However, the self-reported outcomes showed higher scores on 'ease of communication' and overall benefit, and significant lower scores on disability for the new hearing aids when compared to their previous hearing aids with compression amplification. CONCLUSIONS Patients with Usher syndrome type IIa prefer a linear amplification over nonlinear amplification when fitted with novel hearing aids. Apart from a significantly higher logged use, no difference in speech in noise and sound localisation was observed between linear and nonlinear amplification with the currently used tests. Further research is needed to evaluate the reasons behind the preference for the linear settings.
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Affiliation(s)
- B P Hartel
- Department of Otorhinolaryngology, Radboud University Medical Center, Nijmegen, The Netherlands.,Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - M J H Agterberg
- Department of Otorhinolaryngology, Radboud University Medical Center, Nijmegen, The Netherlands.,Department of Biophysics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, The Netherlands
| | - A F Snik
- Department of Otorhinolaryngology, Radboud University Medical Center, Nijmegen, The Netherlands.,Department of Biophysics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, The Netherlands
| | - H P M Kunst
- Department of Otorhinolaryngology, Radboud University Medical Center, Nijmegen, The Netherlands.,Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - A J van Opstal
- Department of Biophysics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, The Netherlands
| | - A J Bosman
- Department of Otorhinolaryngology, Radboud University Medical Center, Nijmegen, The Netherlands.,Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - R J E Pennings
- Department of Otorhinolaryngology, Radboud University Medical Center, Nijmegen, The Netherlands.,Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, The Netherlands
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20
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Antisense Oligonucleotide-based Splice Correction for USH2A-associated Retinal Degeneration Caused by a Frequent Deep-intronic Mutation. MOLECULAR THERAPY. NUCLEIC ACIDS 2016; 5:e381. [PMID: 27802265 DOI: 10.1038/mtna.2016.89] [Citation(s) in RCA: 93] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Accepted: 09/07/2016] [Indexed: 12/21/2022]
Abstract
Usher syndrome (USH) is the most common cause of combined deaf-blindness in man. The hearing loss can be partly compensated by providing patients with hearing aids or cochlear implants, but the loss of vision is currently untreatable. In general, mutations in the USH2A gene are the most frequent cause of USH explaining up to 50% of all patients worldwide. The first deep-intronic mutation in the USH2A gene (c.7595-2144A>G) was reported in 2012, leading to the insertion of a pseudoexon (PE40) into the mature USH2A transcript. When translated, this PE40-containing transcript is predicted to result in a truncated non-functional USH2A protein. In this study, we explored the potential of antisense oligonucleotides (AONs) to prevent aberrant splicing of USH2A pre-mRNA as a consequence of the c.7595-2144A>G mutation. Engineered 2'-O-methylphosphorothioate AONs targeting the PE40 splice acceptor site and/or exonic splice enhancer regions displayed significant splice correction potential in both patient derived fibroblasts and a minigene splice assay for USH2A c.7595-2144A>G, whereas a non-binding sense oligonucleotide had no effect on splicing. Altogether, AON-based splice correction could be a promising approach for the development of a future treatment for USH2A-associated retinitis pigmentosa caused by the deep-intronic c.7595-2144A>G mutation.
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21
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Hartel BP, Löfgren M, Huygen PLM, Guchelaar I, Lo-A-Njoe Kort N, Sadeghi AM, van Wijk E, Tranebjærg L, Kremer H, Kimberling WJ, Cremers CWRJ, Möller C, Pennings RJE. A combination of two truncating mutations in USH2A causes more severe and progressive hearing impairment in Usher syndrome type IIa. Hear Res 2016; 339:60-8. [PMID: 27318125 DOI: 10.1016/j.heares.2016.06.008] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 05/31/2016] [Accepted: 06/13/2016] [Indexed: 11/29/2022]
Abstract
OBJECTIVES Usher syndrome is an inherited disorder that is characterized by hearing impairment (HI), retinitis pigmentosa, and in some cases vestibular dysfunction. Usher syndrome type IIa is caused by mutations in USH2A. HI in these patients is highly heterogeneous and the present study evaluates the effects of different types of USH2A mutations on the audiometric phenotype. Data from two large centres of expertise on Usher Syndrome in the Netherlands and Sweden were combined in order to create a large combined sample of patients to identify possible genotype-phenotype correlations. DESIGN A retrospective study on HI in 110 patients (65 Dutch and 45 Swedish) genetically diagnosed with Usher syndrome type IIa. We used methods especially designed for characterizing and testing differences in audiological phenotype between patient subgroups. These methods included Age Related Typical Audiograms (ARTA) and a method to evaluate the difference in the degree of HI developed throughout life between subgroups. RESULTS Cross-sectional linear regression analysis of last-visit audiograms for the best hearing ear demonstrated a gradual decline of hearing over decades. The congenital level of HI was in the range of 16-33 dB at 0.25-0.5 kHz, and in the range of 51-60 dB at 1-8 kHz. The annual threshold deterioration was in the range of 0.4-0.5 dB/year at 0.25-2 kHz and in the range of 0.7-0.8 dB/year at 4-8 kHz. Patients with two truncating mutations, including homozygotes for the common c.2299delG mutation, developed significantly more severe HI throughout life than patients with one truncating mutation combined with one nontruncating mutation, and patients with two nontruncating mutations. CONCLUSIONS The results have direct implications for patient counselling in terms of prognosis of hearing and may serve as baseline measures for future (genetic) therapeutic interventions.
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Affiliation(s)
- Bas P Hartel
- Department of Otorhinolaryngology, Radboud University Medical Center, Nijmegen, The Netherlands; Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands.
| | - Maria Löfgren
- Swedish Institute for Disability Research (SIDR) Linköping, Sweden; Audiological Research Centre, Örebro University Hospital, Örebro, Sweden; School of Medicine and Health, Örebro University, Örebro, Sweden
| | - Patrick L M Huygen
- Department of Otorhinolaryngology, Radboud University Medical Center, Nijmegen, The Netherlands; Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Iris Guchelaar
- Department of Otorhinolaryngology, Radboud University Medical Center, Nijmegen, The Netherlands; Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Nicole Lo-A-Njoe Kort
- Department of Otorhinolaryngology, Radboud University Medical Center, Nijmegen, The Netherlands; Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Andre M Sadeghi
- The Sahlgrenska Academy, Institute of Neuroscience and Physiology, Department of Audiology, Göteborg, Sweden; Hearing and Deafness Activities Organization, Habilitation & Health, Göteborg, Sweden
| | - Erwin van Wijk
- Department of Otorhinolaryngology, Donders Institute for Brain, Cognition and Behaviour, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Lisbeth Tranebjærg
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark; Department of Otorhinolaryngology, Head and Neck Surgery and Audiology, Bispebjerg Hospital/Rigshospitalet, Copenhagen, Denmark
| | - Hannie Kremer
- Department of Otorhinolaryngology, Donders Institute for Brain, Cognition and Behaviour, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands; Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - William J Kimberling
- Department of Otolaryngology, Molecular Otolaryngology, and Renal Research Laboratories, University of Iowa, Iowa City, IA, USA
| | - Cor W R J Cremers
- Department of Otorhinolaryngology, Radboud University Medical Center, Nijmegen, The Netherlands; Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Claes Möller
- Swedish Institute for Disability Research (SIDR) Linköping, Sweden; Audiological Research Centre, Örebro University Hospital, Örebro, Sweden; School of Medicine and Health, Örebro University, Örebro, Sweden
| | - Ronald J E Pennings
- Department of Otorhinolaryngology, Donders Institute for Brain, Cognition and Behaviour, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
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22
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Lenassi E, Vincent A, Li Z, Saihan Z, Coffey AJ, Steele-Stallard HB, Moore AT, Steel KP, Luxon LM, Héon E, Bitner-Glindzicz M, Webster AR. A detailed clinical and molecular survey of subjects with nonsyndromic USH2A retinopathy reveals an allelic hierarchy of disease-causing variants. Eur J Hum Genet 2015; 23:1318-27. [PMID: 25649381 PMCID: PMC4592079 DOI: 10.1038/ejhg.2014.283] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Revised: 11/20/2014] [Accepted: 12/02/2014] [Indexed: 12/19/2022] Open
Abstract
Defects in USH2A cause both isolated retinal disease and Usher syndrome (ie, retinal disease and deafness). To gain insights into isolated/nonsyndromic USH2A retinopathy, we screened USH2A in 186 probands with recessive retinal disease and no hearing complaint in childhood (discovery cohort) and in 84 probands with recessive retinal disease (replication cohort). Detailed phenotyping, including retinal imaging and audiological assessment, was performed in individuals with two likely disease-causing USH2A variants. Further genetic testing, including screening for a deep-intronic disease-causing variant and large deletions/duplications, was performed in those with one likely disease-causing change. Overall, 23 of 186 probands (discovery cohort) were found to harbour two likely disease-causing variants in USH2A. Some of these variants were predominantly associated with nonsyndromic retinal degeneration (‘retinal disease-specific'); these included the common c.2276 G>T, p.(Cys759Phe) mutation and five additional variants: c.2802 T>G, p.(Cys934Trp); c.10073 G>A, p.(Cys3358Tyr); c.11156 G>A, p.(Arg3719His); c.12295-3 T>A; and c.12575 G>A, p.(Arg4192His). An allelic hierarchy was observed in the discovery cohort and confirmed in the replication cohort. In nonsyndromic USH2A disease, retinopathy was consistent with retinitis pigmentosa and the audiological phenotype was variable. USH2A retinopathy is a common cause of nonsyndromic recessive retinal degeneration and has a different mutational spectrum to that observed in Usher syndrome. The following model is proposed: the presence of at least one ‘retinal disease-specific' USH2A allele in a patient with USH2A-related disease results in the preservation of normal hearing. Careful genotype–phenotype studies such as this will become increasingly important, especially now that high-throughput sequencing is widely used in the clinical setting.
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Affiliation(s)
- Eva Lenassi
- UCL Institute of Ophthalmology and Moorfields Eye Hospital, University College of London, London, UK.,Eye Hospital, University Medical Centre, Ljubljana, Slovenia
| | - Ajoy Vincent
- The Hospital for Sick Children, Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, ON, Canada
| | - Zheng Li
- UCL Institute of Ophthalmology and Moorfields Eye Hospital, University College of London, London, UK.,Ocular Genetics, Singapore Eye Research Institute, Singapore, Singapore
| | - Zubin Saihan
- UCL Institute of Ophthalmology and Moorfields Eye Hospital, University College of London, London, UK
| | | | | | - Anthony T Moore
- UCL Institute of Ophthalmology and Moorfields Eye Hospital, University College of London, London, UK
| | | | - Linda M Luxon
- UCL Ear Institute, London, UK.,National Hospital for Neurology and Neurosurgery, London, UK
| | - Elise Héon
- The Hospital for Sick Children, Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, ON, Canada
| | | | - Andrew R Webster
- UCL Institute of Ophthalmology and Moorfields Eye Hospital, University College of London, London, UK
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Zhao L, Wang F, Wang H, Li Y, Alexander S, Wang K, Willoughby CE, Zaneveld JE, Jiang L, Soens ZT, Earle P, Simpson D, Silvestri G, Chen R. Next-generation sequencing-based molecular diagnosis of 82 retinitis pigmentosa probands from Northern Ireland. Hum Genet 2014; 134:217-30. [PMID: 25472526 DOI: 10.1007/s00439-014-1512-7] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 11/20/2014] [Indexed: 11/24/2022]
Abstract
Retinitis pigmentosa (RP) is a group of inherited retinal disorders characterized by progressive photoreceptor degeneration. An accurate molecular diagnosis is essential for disease characterization and clinical prognoses. A retinal capture panel that enriches 186 known retinal disease genes, including 55 known RP genes, was developed. Targeted next-generation sequencing was performed for a cohort of 82 unrelated RP cases from Northern Ireland, including 46 simplex cases and 36 familial cases. Disease-causing mutations were identified in 49 probands, including 28 simplex cases and 21 familial cases, achieving a solving rate of 60 %. In total, 65 pathogenic mutations were found, and 29 of these were novel. Interestingly, the molecular information of 12 probands was neither consistent with their initial inheritance pattern nor clinical diagnosis. Further clinical reassessment resulted in a refinement of the clinical diagnosis in 11 patients. This is the first study to apply next-generation sequencing-based, comprehensive molecular diagnoses to a large number of RP probands from Northern Ireland. Our study shows that molecular information can aid clinical diagnosis, potentially changing treatment options, current family counseling and management.
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Affiliation(s)
- Li Zhao
- Structural and Computational Biology and Molecular Biophysics, Baylor College of Medicine, Houston, TX, 77030, USA
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24
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Sadeghi AM, Cohn ES, Kimberling WJ, Halvarsson G, Möller C. Expressivity of hearing loss in cases with Usher syndrome type IIA. Int J Audiol 2013; 52:832-7. [PMID: 24160897 DOI: 10.3109/14992027.2013.839885] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE The purpose of this study was to compare the genotype/phenotype relationship between siblings with identical USH2A pathologic mutations and the consequent audiologic phenotypes, in particular degree of hearing loss (HL). Decade audiograms were also compared among two groups of affected subjects with different mutations of USH2A. DESIGN DNA samples from patients with Usher syndrome type II were analysed. The audiological features of patients and affected siblings with USH2A mutations were also examined to identify genotype-phenotype correlations. STUDY SAMPLE Genetic and audiometric examinations were performed in 18 subjects from nine families with Usher syndrome type IIA. RESULTS Three different USH2A mutations were identified in the affected subjects. Both similarities and differences of the auditory phenotype were seen in families with several affected siblings. A variable degree of hearing loss, ranging from mild to profound, was observed among affected subjects. No significant differences in hearing thresholds were found the group of affected subjects with different pathological mutations. CONCLUSIONS Our results indicate that mutations in the USH2A gene and the resulting phenotype are probably modulated by other variables, such as modifying genes, epigenetics or environmental factors which may be of importance for better understanding the etiology of Usher syndrome.
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Affiliation(s)
- André M Sadeghi
- * Department of Audiology, The Sahlgrenska Academy, Institute of Neuroscience and Physiology , Göteborg , Sweden
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25
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Garcia-Garcia G, Aparisi MJ, Jaijo T, Rodrigo R, Leon AM, Avila-Fernandez A, Blanco-Kelly F, Bernal S, Navarro R, Diaz-Llopis M, Baiget M, Ayuso C, Millan JM, Aller E. Mutational screening of the USH2A gene in Spanish USH patients reveals 23 novel pathogenic mutations. Orphanet J Rare Dis 2011; 6:65. [PMID: 22004887 PMCID: PMC3207874 DOI: 10.1186/1750-1172-6-65] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Accepted: 10/17/2011] [Indexed: 11/10/2022] Open
Abstract
Background Usher Syndrome type II (USH2) is an autosomal recessive disorder, characterized by moderate to severe hearing impairment and retinitis pigmentosa (RP). Among the three genes implicated, mutations in the USH2A gene account for 74-90% of the USH2 cases. Methods To identify the genetic cause of the disease and determine the frequency of USH2A mutations in a cohort of 88 unrelated USH Spanish patients, we carried out a mutation screening of the 72 coding exons of this gene by direct sequencing. Moreover, we performed functional minigene studies for those changes that were predicted to affect splicing. Results As a result, a total of 144 DNA sequence variants were identified. Based upon previous studies, allele frequencies, segregation analysis, bioinformatics' predictions and in vitro experiments, 37 variants (23 of them novel) were classified as pathogenic mutations. Conclusions This report provide a wide spectrum of USH2A mutations and clinical features, including atypical Usher syndrome phenotypes resembling Usher syndrome type I. Considering only the patients clearly diagnosed with Usher syndrome type II, and results obtained in this and previous studies, we can state that mutations in USH2A are responsible for 76.1% of USH2 disease in patients of Spanish origin.
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Affiliation(s)
- Gema Garcia-Garcia
- Grupo de Investigación en Enfermedades Neurosensoriales, Instituto de Investigación Sanitaria IIS-La Fe, Valencia, Spain
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26
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A Novel Frameshift Mutation of the USH2A Gene in a Korean Patient with Usher Syndrome Type II. Clin Exp Otorhinolaryngol 2011; 6:41-4. [PMID: 23526569 PMCID: PMC3604269 DOI: 10.3342/ceo.2013.6.1.41] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2010] [Revised: 06/17/2010] [Accepted: 07/29/2010] [Indexed: 11/13/2022] Open
Abstract
Usher syndrome type II (USH2) is the most common form of Usher syndrome, characterized by moderate to severe hearing impairment and progressive visual loss due to retinitis pigmentosa. It has been shown that mutations in the USH2A gene are responsible for USH2. The authors herein describe a 34-year-old Korean woman with the typical clinical manifestation of USH2; she had bilateral hearing disturbance and progressive visual deterioration, without vestibular dysfunction. Molecular genetic study of the USH2A gene revealed a novel frameshift mutation (c.2310delA; Glu771LysfsX17). She was heterozygous for this mutation, and no other mutation was found in USH2A, suggesting the possibility of an intronic or large genomic rearrangement mutation. To the best of our knowledge, this is the first report of a genetically confirmed case of USH2 in Korea. More investigations are needed to delineate genotype-phenotype correlations and ethnicity-specific genetic background of Usher syndrome.
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27
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Nakanishi H, Ohtsubo M, Iwasaki S, Hotta Y, Usami SI, Mizuta K, Mineta H, Minoshima S. Novel USH2A mutations in Japanese Usher syndrome type 2 patients: marked differences in the mutation spectrum between the Japanese and other populations. J Hum Genet 2011; 56:484-90. [PMID: 21593743 DOI: 10.1038/jhg.2011.45] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Usher syndrome (USH) is an autosomal recessive disorder characterized by retinitis pigmentosa and hearing loss. USH type 2 (USH2) is the most common type of USH and is frequently caused by mutations in USH2A. In a recent mutation screening of USH2A in Japanese USH2 patients, we identified 11 novel mutations in 10 patients and found the possible frequent mutation c.8559-2A>G in 4 of 10 patients. To obtain a more precise mutation spectrum, we analyzed further nine Japanese patients in this study. We identified nine mutations, of which eight were novel. This result indicates that the mutation spectrum for USH2A among Japanese patients largely differs from Caucasian, Jewish and Palestinian patients. Meanwhile, we did not find the c.8559-2A>G in this study. Haplotype analysis of the c.8559-2G (mutated) alleles using 23 single nucleotide polymorphisms surrounding the mutation revealed an identical haplotype pattern of at least 635 kb in length, strongly suggesting that the mutation originated from a common ancestor. The fact that all patients carrying c.8559-2A>G came from western Japan suggests that the mutation is mainly distributed in that area; indeed, most of the patients involved in this study came from eastern Japan, which contributed to the absence of c.8559-2A>G.
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Affiliation(s)
- Hiroshi Nakanishi
- Department of Otolaryngology, Hamamatsu University School of Medicine, Hamamatsu, Japan
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28
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Bonnet C, Grati M, Marlin S, Levilliers J, Hardelin JP, Parodi M, Niasme-Grare M, Zelenika D, Délépine M, Feldmann D, Jonard L, El-Amraoui A, Weil D, Delobel B, Vincent C, Dollfus H, Eliot MM, David A, Calais C, Vigneron J, Montaut-Verient B, Bonneau D, Dubin J, Thauvin C, Duvillard A, Francannet C, Mom T, Lacombe D, Duriez F, Drouin-Garraud V, Thuillier-Obstoy MF, Sigaudy S, Frances AM, Collignon P, Challe G, Couderc R, Lathrop M, Sahel JA, Weissenbach J, Petit C, Denoyelle F. Complete exon sequencing of all known Usher syndrome genes greatly improves molecular diagnosis. Orphanet J Rare Dis 2011; 6:21. [PMID: 21569298 PMCID: PMC3125325 DOI: 10.1186/1750-1172-6-21] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2010] [Accepted: 05/11/2011] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND Usher syndrome (USH) combines sensorineural deafness with blindness. It is inherited in an autosomal recessive mode. Early diagnosis is critical for adapted educational and patient management choices, and for genetic counseling. To date, nine causative genes have been identified for the three clinical subtypes (USH1, USH2 and USH3). Current diagnostic strategies make use of a genotyping microarray that is based on the previously reported mutations. The purpose of this study was to design a more accurate molecular diagnosis tool. METHODS We sequenced the 366 coding exons and flanking regions of the nine known USH genes, in 54 USH patients (27 USH1, 21 USH2 and 6 USH3). RESULTS Biallelic mutations were detected in 39 patients (72%) and monoallelic mutations in an additional 10 patients (18.5%). In addition to biallelic mutations in one of the USH genes, presumably pathogenic mutations in another USH gene were detected in seven patients (13%), and another patient carried monoallelic mutations in three different USH genes. Notably, none of the USH3 patients carried detectable mutations in the only known USH3 gene, whereas they all carried mutations in USH2 genes. Most importantly, the currently used microarray would have detected only 30 of the 81 different mutations that we found, of which 39 (48%) were novel. CONCLUSIONS Based on these results, complete exon sequencing of the currently known USH genes stands as a definite improvement for molecular diagnosis of this disease, which is of utmost importance in the perspective of gene therapy.
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Affiliation(s)
- Crystel Bonnet
- Unité de Génétique Médicale, INSERM UMRS 587, Hôpital d'Enfants Armand-Trousseau, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France
- Unité de Génétique et Physiologie de l'Audition, INSERM UMRS 587, UPMC, Institut Pasteur, Paris, France
| | - M'hamed Grati
- Unité de Génétique Médicale, INSERM UMRS 587, Hôpital d'Enfants Armand-Trousseau, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France
- Unité de Génétique et Physiologie de l'Audition, INSERM UMRS 587, UPMC, Institut Pasteur, Paris, France
- NIDCD, NIH, Bethesda, MD 20894, USA
| | - Sandrine Marlin
- Unité de Génétique Médicale, INSERM UMRS 587, Hôpital d'Enfants Armand-Trousseau, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France
| | - Jacqueline Levilliers
- Unité de Génétique et Physiologie de l'Audition, INSERM UMRS 587, UPMC, Institut Pasteur, Paris, France
| | - Jean-Pierre Hardelin
- Unité de Génétique et Physiologie de l'Audition, INSERM UMRS 587, UPMC, Institut Pasteur, Paris, France
| | - Marine Parodi
- Service de Biochimie et de Biologie Moléculaire, INSERM UMRS 587, Hôpital d'Enfants Armand-Trousseau, AP-HP, Paris, France
| | - Magali Niasme-Grare
- Service de Biochimie et de Biologie Moléculaire, INSERM UMRS 587, Hôpital d'Enfants Armand-Trousseau, AP-HP, Paris, France
| | | | | | - Delphine Feldmann
- Unité de Génétique Médicale, INSERM UMRS 587, Hôpital d'Enfants Armand-Trousseau, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France
- Service de Biochimie et de Biologie Moléculaire, INSERM UMRS 587, Hôpital d'Enfants Armand-Trousseau, AP-HP, Paris, France
| | - Laurence Jonard
- Unité de Génétique Médicale, INSERM UMRS 587, Hôpital d'Enfants Armand-Trousseau, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France
- Service de Biochimie et de Biologie Moléculaire, INSERM UMRS 587, Hôpital d'Enfants Armand-Trousseau, AP-HP, Paris, France
| | - Aziz El-Amraoui
- Unité de Génétique et Physiologie de l'Audition, INSERM UMRS 587, UPMC, Institut Pasteur, Paris, France
| | - Dominique Weil
- Unité de Génétique et Physiologie de l'Audition, INSERM UMRS 587, UPMC, Institut Pasteur, Paris, France
| | - Bruno Delobel
- Centre de Génétique, Hôpital St-Antoine, Lille, France
| | | | - Hélène Dollfus
- Service de Génétique médicale, Hôpital de Hautepierre, Strasbourg, France
| | | | - Albert David
- Service de Génétique, Hôtel Dieu, Nantes, France
| | | | | | | | - Dominique Bonneau
- Centre de Référence des Maladies Neurogénétiques, Centre Hospitalier Universitaire d'Angers, France
| | - Jacques Dubin
- Service ORL, Centre Hospitalier Universitaire d'Angers, France
| | | | | | | | - Thierry Mom
- Service ORL, Hôtel-Dieu, Clermont-Ferrand, France
| | - Didier Lacombe
- Centre de Génétique, Hôpital Pellegrin, Bordeaux, France
| | | | | | | | - Sabine Sigaudy
- Service de Génétique Médicale, Hôpital de la Timone, Marseille, France
| | - Anne-Marie Frances
- Service de Génétique Médicale, Hôpital intercommunal de Font-Pré, Toulon La Seyne sur Mer, France
| | - Patrick Collignon
- Service de Génétique Médicale, Hôpital intercommunal de Font-Pré, Toulon La Seyne sur Mer, France
| | - Georges Challe
- Departement d'Ophtalmologie et de Médecine Interne, Hôpital de la Salpêtrière, AP-HP, France
| | - Rémy Couderc
- Unité de Génétique Médicale, INSERM UMRS 587, Hôpital d'Enfants Armand-Trousseau, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France
- Service de Biochimie et de Biologie Moléculaire, INSERM UMRS 587, Hôpital d'Enfants Armand-Trousseau, AP-HP, Paris, France
| | - Mark Lathrop
- Centre National de Génotypage, CEA, Evry, France
| | | | - Jean Weissenbach
- CEA, DSV, IG, Genoscope, CNRS-UMR 8030, UEVE, Université d'Evry, Evry, France
| | - Christine Petit
- Unité de Génétique et Physiologie de l'Audition, INSERM UMRS 587, UPMC, Institut Pasteur, Paris, France
- Collège de France, Paris, France
| | - Françoise Denoyelle
- Unité de Génétique et Physiologie de l'Audition, INSERM UMRS 587, UPMC, Institut Pasteur, Paris, France
- Service d'ORL et de Chirurgie Cervico-faciale, INSERM UMRS 587, Hôpital d'Enfants Armand-Trousseau, AP-HP, UPMC, Paris, France
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Vaché C, Besnard T, Blanchet C, Baux D, Larrieu L, Faugère V, Mondain M, Hamel C, Malcolm S, Claustres M, Roux AF. Nasal epithelial cells are a reliable source to study splicing variants in Usher syndrome. Hum Mutat 2010; 31:734-41. [PMID: 20513143 DOI: 10.1002/humu.21255] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
We have shown that nasal ciliated epithelium, which can be easily biopsied under local anesthetic, provides a good source of RNA transcripts from eight of the nine known genes that cause Usher syndrome, namely, MYO7A, USH1C, CDH23, PCDH15, USH1G for Usher type 1, and USH2A, GPR98, WHRN for Usher type 2. Furthermore, the known or predicted effect on mRNA splicing of eight variants was faithfully reproduced in the biopsied sample as measured by nested RT-PCR. These included changes at the canonical acceptor site, changes within the noncanonical acceptor site and both synonymous and nonsynonymous amino acid changes. This shows that mRNA analysis by this method will help in assessing the pathogenic effect of variants, which is a major problem in the molecular diagnosis of Usher syndrome.
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Affiliation(s)
- Christel Vaché
- CHU Montpellier, Laboratoire de Génétique Moléculaire, Montpellier, France
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30
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Liu X, Tang Z, Li C, Yang K, Gan G, Zhang Z, Liu J, Jiang F, Wang Q, Liu M. Novel USH2A compound heterozygous mutations cause RP/USH2 in a Chinese family. Mol Vis 2010; 16:454-61. [PMID: 20309401 PMCID: PMC2842093 DOI: 10.1167/3.9.454] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2009] [Accepted: 03/09/2010] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To identify the disease-causing gene in a four-generation Chinese family affected with retinitis pigmentosa (RP). METHODS Linkage analysis was performed with a panel of microsatellite markers flanking the candidate genetic loci of RP. These loci included 38 known RP genes. The complete coding region and exon-intron boundaries of Usher syndrome 2A (USH2A) were sequenced with the proband DNA to screen the disease-causing gene mutation. Restriction fragment length polymorphism (RFLP) analysis and direct DNA sequence analysis were done to demonstrate co-segregation of the USH2A mutations with the family disease. One hundred normal controls were used without the mutations. RESULTS The disease-causing gene in this Chinese family was linked to the USH2A locus on chromosome 1q41. Direct DNA sequence analysis of USH2A identified two novel mutations in the patients: one missense mutation p.G1734R in exon 26 and a splice site mutation, IVS32+1G>A, which was found in the donor site of intron 32 of USH2A. Neither the p.G1734R nor the IVS32+1G>A mutation was found in the unaffected family members or the 100 normal controls. One patient with a homozygous mutation displayed only RP symptoms until now, while three patients with compound heterozygous mutations in the family of study showed both RP and hearing impairment. CONCLUSIONS This study identified two novel mutations: p.G1734R and IVS32+1G>A of USH2A in a four-generation Chinese RP family. In this study, the heterozygous mutation and the homozygous mutation in USH2A may cause Usher syndrome Type II or RP, respectively. These two mutations expand the mutant spectrum of USH2A.
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Affiliation(s)
- Xiaowen Liu
- The Union Hospital, Huazhong University of Science and Technology, Wuhan, Hubei, P.R. China
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31
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Aller E, Larrieu L, Jaijo T, Baux D, Espinós C, González-Candelas F, Nájera C, Palau F, Claustres M, Roux AF, Millán JM. The USH2A c.2299delG mutation: dating its common origin in a Southern European population. Eur J Hum Genet 2010; 18:788-93. [PMID: 20145675 DOI: 10.1038/ejhg.2010.14] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Usher syndrome type II is the most common form of Usher syndrome. USH2A is the main responsible gene of the three known to be disease causing. It encodes two isoforms of the protein usherin. This protein is part of an interactome that has an essential role in the development and function of inner ear hair cells and photoreceptors. The gene contains 72 exons spanning over a region of 800 kb. Although numerous mutations have been described, the c.2299delG mutation is the most prevalent in several populations. Its ancestral origin was previously suggested after the identification of a common core haplotype restricted to 250 kb in the 5' region that encodes the short usherin isoform. By extending the haplotype analysis over the 800 kb region of the USH2A gene with a total of 14 intragenic single nucleotide polymorphisms, we have been able to define 10 different c.2299delG haplotypes, showing high variability but preserving the previously described core haplotype. An exhaustive c.2299delG/control haplotype study suggests that the major source of variability in the USH2A gene is recombination. Furthermore, we have evidenced twice the amount of recombination hotspots located in the 500 kb region that covers the 3' end of the gene, explaining the higher variability observed in this region when compared with the 250 kb of the 5' region. Our data confirm the common ancestral origin of the c.2299delG mutation.
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Affiliation(s)
- Elena Aller
- Unidad de Genética, Hospital Universitario La Fe, Valencia, Spain
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32
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Mutation analysis in the long isoform of USH2A in American patients with Usher Syndrome type II. J Hum Genet 2009; 54:732-8. [PMID: 19881469 DOI: 10.1038/jhg.2009.107] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Usher syndrome type II (USH2) is an autosomal recessive disorder characterized by moderate to severe hearing impairment and progressive visual loss due to retinitis pigmentosa (RP). To identify novel mutations and determine the frequency of USH2A mutations as a cause of USH2, we have carried out mutation screening of all 72 coding exons and exon-intron splice sites of the USH2A gene. A total of 20 USH2 American probands of European descent were analyzed using single strand conformational polymorphism (SSCP) and direct sequencing methods. Ten different USH2A mutations were identified in 55% of the probands, five of which were novel mutations. The detected mutations include three missense, three frameshifts and four nonsense mutations, with c.2299delG/p.E767fs mutation, accounting for 38.9% of the pathological alleles. Two cases were homozygotes, two cases were compound heterozygotes and one case had complex allele with three variants. In seven probands, only one USH2A mutation was detected and no pathological mutation was found in the remaining eight individuals. Altogether, our data support the fact that c.2299delG/p.E767fs is indeed the most common USH2A mutation found in USH2 patients of European Caucasian background. Thus, if screening for mutations in USH2A is considered, it is reasonable to screen for the c.2299delG mutation first.
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Nakanishi H, Ohtsubo M, Iwasaki S, Hotta Y, Mizuta K, Mineta H, Minoshima S. Identification of 11 novel mutations in USH2A among Japanese patients with Usher syndrome type 2. Clin Genet 2009; 76:383-91. [PMID: 19737284 DOI: 10.1111/j.1399-0004.2009.01257.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Usher syndrome (USH) is an autosomal recessive disorder characterized by retinitis pigmentosa and hearing loss. USH type 2 (USH2) is the most common type of USH and is frequently caused by mutations in USH2A, which accounts for 74-90% of USH2 cases. This is the first study reporting the results of scanning for USH2A mutations in Japanese patients with USH2. In 8 of 10 unrelated patients, we identified 14 different mutations. Of these mutations, 11 were novel. Although the mutation spectrum that we identified differed from that for Caucasians, the incidence of mutations in USH2A was 80% for all patients tested, which is consistent with previous findings. Further, c.8559-2A>G was identified in four patients and accounted for 26.7% of mutated alleles; it is thus a frequent mutation in Japanese patients. Hence, mutation screening for c.8559-2A>G in USH2A may prove very effective for the early diagnosis of USH2.
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Affiliation(s)
- H Nakanishi
- Department of Otolaryngology, Hamamatsu University School of Medicine, Hamamatsu, Japan
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34
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Baux D, Larrieu L, Blanchet C, Hamel C, Ben Salah S, Vielle A, Gilbert-Dussardier B, Holder M, Calvas P, Philip N, Edery P, Bonneau D, Claustres M, Malcolm S, Roux AF. Molecular and in silico analyses of the full-length isoform of usherin identify new pathogenic alleles in Usher type II patients. Hum Mutat 2007; 28:781-9. [PMID: 17405132 DOI: 10.1002/humu.20513] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The usherin gene (USH2A) has been screened for mutations causing Usher syndrome type II (USH2). Two protein isoforms have been identified: a short isoform of 1,546 amino acids and a more recently recognized isoform extending to 5,202 amino acids. We have screened the full length by genomic sequencing. We confirm that many mutations occur in the exons contributing solely to the longer form. USH2 is an autosomal recessive disorder and, in contrast to previous studies, both mutations were identified in 23 patients and a single mutation in 2 out of 33 patients. A total of 34 distinct mutated alleles were identified, including one complex allele with three variants and another with two. A total of 27 of these are novel, confirming that most mutations in usherin are private. Many of the mutations will lead to prematurely truncated protein but as there are a substantial number of missense variants, we have used in silico analysis to assess their pathogenicity. Evidence that they are disease-causing has been produced by protein alignments and three-dimensional (3D) structural predictions when possible. We have identified a previously unrecognized cysteine rich structural domain, containing 12 dicysteine repeats, and show that three missense mutations result in the loss of one of a pair of the defining cysteine-cysteine pairs.
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Affiliation(s)
- David Baux
- Centre Hospitalier Universitaire (CHU) Montpellier, Laboratoire de Génétique Moléculaire, Montpellier, France
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35
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Ebermann I, Walger M, Scholl HPN, Charbel Issa P, Lüke C, Nürnberg G, Lang-Roth R, Becker C, Nürnberg P, Bolz HJ. Truncating mutation of theDFNB59gene causes cochlear hearing impairment and central vestibular dysfunction. Hum Mutat 2007; 28:571-7. [PMID: 17301963 DOI: 10.1002/humu.20478] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
We have identified a consanguineous family from Morocco segregating autosomal recessive congenital progressive hearing loss (ARNSHL) and retinal degeneration. Detailed clinical investigation of the six siblings revealed combined severe cone-rod dystrophy (CORD) and severe/profound hearing impairment in two of them, while there is isolated CORD in three and nonsyndromic profound hearing loss in one. We therefore assumed a partial overlap of two nonsyndromic autosomal recessive conditions instead of a monogenic syndrome and performed genomewide linkage analysis. The disease loci were mapped to chromosome 2q31.1-2q32.1 for ARNSHL and to 2q13-2q14.1 for CORD, respectively. The retinal phenotype was shown to be due to homozygosity for a novel splice site mutation, c.2189+1G>T, in the retinitis pigmentosa gene MERTK. The ARNSHL interval comprised the DFNB59 locus. The DFNB59 gene has been identified recently, and two missense mutations (p.R183W and p.T54I) have been shown to cause auditory neuropathy in both humans and transgenic mice. Mutation screening in the DFNB59 gene in our family revealed homozygosity for a 1-bp insertion in exon 2 (c.113_114insT), predicting a truncated protein of 47 amino acids, in all three hearing impaired subjects. This is the first description of biallelic putative loss-of-function of the DFNB59 gene. Detailed audiological investigation clearly indicated hair cell dysfunction and, in contrast to cases reported previously, excluded auditory neuropathy. We show that besides otoferlin (OTOF), DFNB59 is the second known gene in which mutations can result in these two distinct forms of hearing impairment. Moreover, all patients in our family with homozygosity for the DFNB59 mutation display central vestibular dysfunction.
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Affiliation(s)
- Inga Ebermann
- Institute of Human Genetics, University Hospital of Cologne, Cologne, Germany
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36
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Liu X, Bulgakov OV, Darrow KN, Pawlyk B, Adamian M, Liberman MC, Li T. Usherin is required for maintenance of retinal photoreceptors and normal development of cochlear hair cells. Proc Natl Acad Sci U S A 2007; 104:4413-8. [PMID: 17360538 PMCID: PMC1838616 DOI: 10.1073/pnas.0610950104] [Citation(s) in RCA: 189] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Usher syndrome type IIA (USH2A), characterized by progressive photoreceptor degeneration and congenital moderate hearing loss, is the most common subtype of Usher syndrome. In this article, we show that the USH2A protein, also known as usherin, is an exceptionally large ( approximately 600-kDa) matrix protein expressed specifically in retinal photoreceptors and developing cochlear hair cells. In mammalian photoreceptors, usherin is localized to a spatially restricted membrane microdomain at the apical inner segment recess that wraps around the connecting cilia, corresponding to the periciliary ridge complex described for amphibian photoreceptors. In sensory hair cells of the cochlea, it is associated transiently with the hair bundles during postnatal development. Targeted disruption of the Ush2a gene in mice leads to progressive photoreceptor degeneration and a moderate but nonprogressive hearing impairment, mimicking the visual and hearing deficits in USH2A patients. These data suggest that usherin is required for the long-term maintenance of retinal photoreceptors and for the development of cochlear hair cells. We propose a model in which usherin in photoreceptors is tethered via its C terminus to the plasma membrane and its large extracellular domain projecting into the periciliary matrix, where they may interact with the connecting cilium to fulfill important structural or signaling roles.
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Affiliation(s)
- Xiaoqing Liu
- *Berman–Gund Laboratory for the Study of Retinal Degenerations and
| | - Oleg V. Bulgakov
- *Berman–Gund Laboratory for the Study of Retinal Degenerations and
| | - Keith N. Darrow
- Eaton–Peabody Laboratory, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston, MA 02114
| | - Basil Pawlyk
- *Berman–Gund Laboratory for the Study of Retinal Degenerations and
| | - Michael Adamian
- *Berman–Gund Laboratory for the Study of Retinal Degenerations and
| | - M. Charles Liberman
- Eaton–Peabody Laboratory, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston, MA 02114
| | - Tiansen Li
- *Berman–Gund Laboratory for the Study of Retinal Degenerations and
- To whom correspondence should be addressed at:
Massachusetts Eye and Ear Infirmary, 243 Charles Street, Boston, MA 02114. E-mail:
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Aller E, Jaijo T, Beneyto M, Nájera C, Oltra S, Ayuso C, Baiget M, Carballo M, Antiñolo G, Valverde D, Moreno F, Vilela C, Collado D, Pérez-Garrigues H, Navea A, Millán JM. Identification of 14 novel mutations in the long isoform of USH2A in Spanish patients with Usher syndrome type II. J Med Genet 2006; 43:e55. [PMID: 17085681 PMCID: PMC2563181 DOI: 10.1136/jmg.2006.041764] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Mutations in USH2A gene have been shown to be responsible for Usher syndrome type II, an autosomal recessive disorder characterised by hearing loss and retinitis pigmentosa. USH2A was firstly described as consisting of 21 exons, but 52 novel exons at the 3' end of the gene were recently identified. In this report, a mutation analysis of the new 52 exons of USH2A gene was carried out in 32 unrelated patients in which both disease-causing mutations could not be found after the screening of the first 21 exons of the USH2A gene. On analysing the new 52 exons, fourteen novel mutations were identified in 14 out of the 32 cases studied, including 7 missense, 5 frameshift, 1 duplication and a putative splice-site mutation.
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Affiliation(s)
- E Aller
- Unit of Genetics, Hospital La Fe, Avda Campanar, 21, 46009 Valencia, Spain
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38
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Ebermann I, Scholl HPN, Charbel Issa P, Becirovic E, Lamprecht J, Jurklies B, Millán JM, Aller E, Mitter D, Bolz H. A novel gene for Usher syndrome type 2: mutations in the long isoform of whirlin are associated with retinitis pigmentosa and sensorineural hearing loss. Hum Genet 2006; 121:203-11. [PMID: 17171570 DOI: 10.1007/s00439-006-0304-0] [Citation(s) in RCA: 141] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2006] [Accepted: 11/18/2006] [Indexed: 10/23/2022]
Abstract
Usher syndrome is an autosomal recessive condition characterized by sensorineural hearing loss, variable vestibular dysfunction, and visual impairment due to retinitis pigmentosa (RP). The seven proteins that have been identified for Usher syndrome type 1 (USH1) and type 2 (USH2) may interact in a large protein complex. In order to identify novel USH genes, we followed a candidate strategy, assuming that mutations in proteins interacting with this "USH network" may cause Usher syndrome as well. The DFNB31 gene encodes whirlin, a PDZ scaffold protein with expression in both hair cell stereocilia and retinal photoreceptor cells. Whirlin represents an excellent candidate for USH2 because it binds to Usherin (USH2A) and VLGR1b (USH2C). Genotyping of microsatellite markers specific for the DFNB31 gene locus on chromosome 9q32 was performed in a German USH2 family that had been excluded for all known USH loci. Patients showed common haplotypes. Sequence analysis of DFNB31 revealed compound heterozygosity for a nonsense mutation, p.Q103X, in exon 1, and a mutation in the splice donor site of exon 2, c.837+1G>A. DFNB31 mutations appear to be a rare cause of Usher syndrome, since no mutations were identified in an additional 96 USH2 patients. While mutations in the C-terminal half of whirlin have previously been reported in non-syndromic deafness (DFNB31), both alterations identified in our USH2 family affect the long protein isoform. We propose that mutations causing Usher syndrome are probably restricted to exons 1-6 that are specific for the long isoform and probably crucial for retinal function. We describe a novel genetic subtype for Usher syndrome, which we named USH2D and which is caused by mutations in whirlin. Moreover, this is the first case of USH2 that is allelic to non-syndromic deafness.
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Affiliation(s)
- Inga Ebermann
- Institute of Human Genetics, University Hospital of Cologne, Kerpener Str. 34, 50931 Cologne, Germany
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Cremers FPM, Kimberling WJ, Külm M, de Brouwer AP, van Wijk E, te Brinke H, Cremers CWRJ, Hoefsloot LH, Banfi S, Simonelli F, Fleischhauer JC, Berger W, Kelley PM, Haralambous E, Bitner-Glindzicz M, Webster AR, Saihan Z, De Baere E, Leroy BP, Silvestri G, McKay GJ, Koenekoop RK, Millan JM, Rosenberg T, Joensuu T, Sankila EM, Weil D, Weston MD, Wissinger B, Kremer H. Development of a genotyping microarray for Usher syndrome. J Med Genet 2006; 44:153-60. [PMID: 16963483 PMCID: PMC2598068 DOI: 10.1136/jmg.2006.044784] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Usher syndrome, a combination of retinitis pigmentosa (RP) and sensorineural hearing loss with or without vestibular dysfunction, displays a high degree of clinical and genetic heterogeneity. Three clinical subtypes can be distinguished, based on the age of onset and severity of the hearing impairment, and the presence or absence of vestibular abnormalities. Thus far, eight genes have been implicated in the syndrome, together comprising 347 protein-coding exons. METHODS To improve DNA diagnostics for patients with Usher syndrome, we developed a genotyping microarray based on the arrayed primer extension (APEX) method. Allele-specific oligonucleotides corresponding to all 298 Usher syndrome-associated sequence variants known to date, 76 of which are novel, were arrayed. RESULTS Approximately half of these variants were validated using original patient DNAs, which yielded an accuracy of >98%. The efficiency of the Usher genotyping microarray was tested using DNAs from 370 unrelated European and American patients with Usher syndrome. Sequence variants were identified in 64/140 (46%) patients with Usher syndrome type I, 45/189 (24%) patients with Usher syndrome type II, 6/21 (29%) patients with Usher syndrome type III and 6/20 (30%) patients with atypical Usher syndrome. The chip also identified two novel sequence variants, c.400C>T (p.R134X) in PCDH15 and c.1606T>C (p.C536S) in USH2A. CONCLUSION The Usher genotyping microarray is a versatile and affordable screening tool for Usher syndrome. Its efficiency will improve with the addition of novel sequence variants with minimal extra costs, making it a very useful first-pass screening tool.
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Affiliation(s)
- Frans P M Cremers
- Department of Human Genetics, and Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
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40
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Mezer E, Sutherland J, Goei SL, Héon E, Levin AV. Utility of molecular testing for related retinal dystrophies. Can J Ophthalmol 2006; 41:190-6. [PMID: 16767206 DOI: 10.1139/i06-007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND The purpose of this study was to describe our experience with the clinical effects of molecular genetic testing for retinitis pigmentosa (RP) and related retinal dystrophies. METHODS Chart review of 303 consecutive patients with retinal dystrophies was done when blood was sent for molecular genetic testing between 1993 and 2001. Phenotype information was retrieved for patients with identified mutations. The yield of positive and clinically useful results was assessed. RESULTS Participants comprised 35 patients with Leber congenital amaurosis, 18 with Usher syndrome, and 250 with isolated RP or other retinal dystrophies. Of these 303 participants, 203 (67%) received positive or negative results of molecular testing for an average of 2.7 genes. Positive results were available in 19 patients after an average time interval of 38+/-22 months (median 33 months, range 1-89 months). No results were received for 84 (28%) patients. In 16 (5%) cases, patients received partial results. Only 19 (6%) patients were found to have sequence changes in RHO, RDS, CRB1, or USH2A, 2 of which were thought to be disease-causing. Only 2 sequence changes were previously documented mutations, but several other novel changes were suspected to be disease-causing mutations also. INTERPRETATION Molecular testing was helpful only in the minority of cases, largely because of a lack of availability, as well as the complexity of the molecular genetics of RP. Improvements in funding, infrastructure, and molecular knowledge will be necessary to improve the transformation of molecular genetic testing into a clinically relevant bedside tool.
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Affiliation(s)
- Eedy Mezer
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, University of Toronto, Ontario, Canada
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41
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Bernal S, Medà C, Solans T, Ayuso C, Garcia-Sandoval B, Valverde D, Del Rio E, Baiget M. Clinical and genetic studies in Spanish patients with Usher syndrome type II: description of new mutations and evidence for a lack of genotype--phenotype correlation. Clin Genet 2005; 68:204-14. [PMID: 16098008 DOI: 10.1111/j.1399-0004.2005.00481.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Patients with Usher syndrome type II (USH2) show moderate-to-severe hearing loss (HL), retinitis pigmentosa and normal vestibular function. The progression of HL remains controversial. To evaluate whether a phenotype-genotype correlation exists regarding the issue of progression of HL, only USH2 patients with a defined genotype were selected. Ophthalmologic, vestibular and audiometric examination along with a mutation analysis of the USH2A gene (exons 1--21) was performed in twenty-eight Spanish USH2 patients. Ten different pathogenic mutations and 17 sequence variants not associated with the disease were found. Six of the 10 mutations are novel. Disease alleles were identified in 13 of the 28 families tested. Eight of these 13 families had a mutation found in both alleles. In the other five families, only one mutation was identified. The phenotypic data provide evidence for the existence of phenotypic differences between patients with the same genotype. These differences were observed at both the interfamilial and intrafamilial levels.
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Affiliation(s)
- S Bernal
- Servei de Genètica, Universidad de Vigo, Vigo, Spain
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42
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van Wijk E, Pennings RJE, te Brinke H, Claassen A, Yntema HG, Hoefsloot LH, Cremers FPM, Cremers CWRJ, Kremer H. Identification of 51 novel exons of the Usher syndrome type 2A (USH2A) gene that encode multiple conserved functional domains and that are mutated in patients with Usher syndrome type II. Am J Hum Genet 2004; 74:738-44. [PMID: 15015129 PMCID: PMC1181950 DOI: 10.1086/383096] [Citation(s) in RCA: 144] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2003] [Accepted: 01/15/2004] [Indexed: 11/03/2022] Open
Abstract
The USH2A gene is mutated in patients with Usher syndrome type IIa, which is the most common subtype of Usher syndrome and is characterized by hearing loss and retinitis pigmentosa. Since mutation analysis by DNA sequencing of exons 1-21 revealed only ~63% of the expected USH2A mutations, we searched for so-far-uncharacterized exons of the gene. We identified 51 novel exons at the 3' end of the gene, and we obtained indications for alternative splicing. The putative protein encoded by the longest open reading frame harbors, in addition to the known functional domains, two laminin G and 28 fibronectin type III repeats, as well as a transmembrane region followed by an intracellular domain with a PDZ-binding domain at its C-terminal end. Semiquantitative expression profile analysis suggested a low level of expression for both the long and the short isoform(s) and partial overlap in spatial and temporal expression patterns. Mutation analysis in 12 unrelated patients with Usher syndrome, each with one mutation in exons 1-21, revealed three different truncating mutations in four patients and two missense mutations in one patient. The presence of pathogenic mutations in the novel exons indicates that at least one of the putative long isoforms of the USH2A protein plays a role in both hearing and vision.
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Affiliation(s)
- Erwin van Wijk
- Departments of Otorhinolaryngology and Human Genetics, University Medical Center Nijmegen, Nijmegen, The Netherlands
| | - Ronald J. E. Pennings
- Departments of Otorhinolaryngology and Human Genetics, University Medical Center Nijmegen, Nijmegen, The Netherlands
| | - Heleen te Brinke
- Departments of Otorhinolaryngology and Human Genetics, University Medical Center Nijmegen, Nijmegen, The Netherlands
| | - Annemarie Claassen
- Departments of Otorhinolaryngology and Human Genetics, University Medical Center Nijmegen, Nijmegen, The Netherlands
| | - Helger G. Yntema
- Departments of Otorhinolaryngology and Human Genetics, University Medical Center Nijmegen, Nijmegen, The Netherlands
| | - Lies H. Hoefsloot
- Departments of Otorhinolaryngology and Human Genetics, University Medical Center Nijmegen, Nijmegen, The Netherlands
| | - Frans P. M. Cremers
- Departments of Otorhinolaryngology and Human Genetics, University Medical Center Nijmegen, Nijmegen, The Netherlands
| | - Cor. W. R. J. Cremers
- Departments of Otorhinolaryngology and Human Genetics, University Medical Center Nijmegen, Nijmegen, The Netherlands
| | - Hannie Kremer
- Departments of Otorhinolaryngology and Human Genetics, University Medical Center Nijmegen, Nijmegen, The Netherlands
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