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Wei C, Yang L, Cheng J, Imani S, Fu S, Lv H, Li Y, Chen R, Leung ELH, Fu J. A novel homozygous variant of GPR98 causes usher syndrome type IIC in a consanguineous Chinese family by next generation sequencing. BMC MEDICAL GENETICS 2018; 19:99. [PMID: 29890953 PMCID: PMC5996530 DOI: 10.1186/s12881-018-0602-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 05/01/2018] [Indexed: 11/10/2022]
Abstract
BACKGROUND Usher syndrome (USH) is a common heterogeneous retinopathy and a hearing loss (HL) syndrome. However, the gene causing Usher syndrome type IIC (USH2C) in a consanguineous Chinese pedigree is unknown. METHODS We performed targeted next-generation sequencing analysis and Sanger sequencing to explore the GPR98 mutations in a USH2C pedigree that included a 32-year-old male patient from a consanguineous marriage family. Western blot verified the nonsense mutation. RESULTS To identify disease-causing gene variants in a consanguineous Chinese pedigree with USH2C, DNA from proband was analyzed using targeted next generation sequencing (NGS). The patient was clinically documented as a possible USH2 by a comprehensive auditory and ophthalmology evaluation. We succeeded in identifying the deleterious, novel, and homologous variant, c.6912dupG (p.Leu2305Valfs*4), in the GPR98 gene (NM_032119.3) that contributes to the progression of USH2C. Variant detected by targeted NGS was then confirmed and co-segregation was conducted by direct Sanger sequencing. Western blot verified losing almost two-thirds of its amino acid residues, including partial Calx-beta, whole EPTP and 7TM-GPCRs at the C-terminus of GPR98. Furthermore, our results highlighted that this p.Leu2305Valfs*4 variant is most likely pathogenic due to a large deletion at the seven-transmembrane G protein-coupled receptors (7TM-GPCRs) domain in GPR98 protein, leading to significantly decreased functionality and complex stability. CONCLUSIONS These findings characterized the novel disease causativeness variant in GPR98 and broaden mutation spectrums, which could predict the pathogenic progression of patient with USH2C, guide diagnosis and treatment of this disease; and provide genetic counseling and family planning for consanguineous marriage pedigree in developing countries, including China.
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Affiliation(s)
- Chunli Wei
- State Key Laboratory of Quality Research in Chinese Medicine, Macau Institute For Applied Research in Medicine and Health, Macau University of Science and Technology, Taipa, Macao, Special Administrative Region of China.,Key Laboratory of Epigenetics and Oncology, Research Center for Preclinical Medicine, Southwest Medical University, Luzhou, Sichuan, China
| | - Lisha Yang
- Key Laboratory of Epigenetics and Oncology, Research Center for Preclinical Medicine, Southwest Medical University, Luzhou, Sichuan, China
| | - Jingliang Cheng
- Key Laboratory of Epigenetics and Oncology, Research Center for Preclinical Medicine, Southwest Medical University, Luzhou, Sichuan, China
| | - Saber Imani
- Key Laboratory of Epigenetics and Oncology, Research Center for Preclinical Medicine, Southwest Medical University, Luzhou, Sichuan, China.,Chemical Injuries Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Shangyi Fu
- The Honors College, University of Houston, Houston, TX, USA.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Hongbin Lv
- Department of Ophthalmology, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, China
| | - Yumei Li
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Rui Chen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Elaine Lai-Han Leung
- State Key Laboratory of Quality Research in Chinese Medicine, Macau Institute For Applied Research in Medicine and Health, Macau University of Science and Technology, Taipa, Macao, Special Administrative Region of China. .,Guangzhou Institute of Respiratory Disease, State Key Laboratory of Respiratory Disease, The 1st Affiliated Hospital of Guangzhou Medical College, Guangzhou, China. .,Respiratoire Medicine Department, Taihe Hospital, Hubei University of Medicine, Hubei, China.
| | - Junjiang Fu
- State Key Laboratory of Quality Research in Chinese Medicine, Macau Institute For Applied Research in Medicine and Health, Macau University of Science and Technology, Taipa, Macao, Special Administrative Region of China. .,Key Laboratory of Epigenetics and Oncology, Research Center for Preclinical Medicine, Southwest Medical University, Luzhou, Sichuan, China.
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Egilmez OK, Kalcioglu MT. Genetics of Nonsyndromic Congenital Hearing Loss. SCIENTIFICA 2016; 2016:7576064. [PMID: 26989561 PMCID: PMC4775805 DOI: 10.1155/2016/7576064] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 01/19/2016] [Indexed: 06/05/2023]
Abstract
Congenital hearing impairment affects nearly 1 in every 1000 live births and is the most frequent birth defect in developed societies. Hereditary types of hearing loss account for more than 50% of all congenital sensorineural hearing loss cases and are caused by genetic mutations. HL can be either nonsyndromic, which is restricted to the inner ear, or syndromic, a part of multiple anomalies affecting the body. Nonsyndromic HL can be categorised by mode of inheritance, such as autosomal dominant (called DFNA), autosomal recessive (DFNB), mitochondrial, and X-linked (DFN). To date, 125 deafness loci have been reported in the literature: 58 DFNA loci, 63 DFNB loci, and 4 X-linked loci. Mutations in genes that control the adhesion of hair cells, intracellular transport, neurotransmitter release, ionic hemeostasis, and cytoskeleton of hair cells can lead to malfunctions of the cochlea and inner ear. In recent years, with the increase in studies about genes involved in congenital hearing loss, genetic counselling and treatment options have emerged and increased in availability. This paper presents an overview of the currently known genes associated with nonsyndromic congenital hearing loss and mutations in the inner ear.
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Affiliation(s)
- Oguz Kadir Egilmez
- Department of Otorhinolaryngology, Faculty of Medicine, Istanbul Medeniyet University, 34722 Istanbul, Turkey
| | - M. Tayyar Kalcioglu
- Department of Otorhinolaryngology, Faculty of Medicine, Istanbul Medeniyet University, 34722 Istanbul, Turkey
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Zaki MS, Heller R, Thoenes M, Nürnberg G, Stern-Schneider G, Nürnberg P, Karnati S, Swan D, Fateen E, Nagel-Wolfrum K, Mostafa MI, Thiele H, Wolfrum U, Baumgart-Vogt E, Bolz HJ. PEX6 is Expressed in Photoreceptor Cilia and Mutated in Deafblindness with Enamel Dysplasia and Microcephaly. Hum Mutat 2015; 37:170-4. [PMID: 26593283 DOI: 10.1002/humu.22934] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 11/12/2015] [Indexed: 02/06/2023]
Abstract
Deafblindness is part of several genetic disorders. We investigated a consanguineous Egyptian family with two siblings affected by congenital hearing loss and retinal degeneration, initially diagnosed as Usher syndrome type 1. At teenage, severe enamel dysplasia, developmental delay, and microcephaly became apparent. Genome-wide homozygosity mapping and whole-exome sequencing detected a homozygous missense mutation, c.1238G>T (p.Gly413Val), affecting a highly conserved residue of peroxisomal biogenesis factor 6, PEX6. Biochemical profiling of the siblings revealed abnormal and borderline plasma phytanic acid concentration, and cerebral imaging revealed white matter disease in both. We show that Pex6 localizes to the apical extensions of secretory ameloblasts and differentiated odontoblasts at early stages of dentin synthesis in mice, and to cilia of retinal photoreceptor cells. We propose PEX6, and possibly other peroxisomal genes, as candidate for the rare cooccurrence of deafblindness and enamel dysplasia. Our study for the first time links peroxisome biogenesis disorders to retinal ciliopathies.
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Affiliation(s)
- Maha S Zaki
- Department of Clinical Genetics, Human Genetics and Genome Research Division, National Research Centre, Cairo, Egypt
| | - Raoul Heller
- Institute of Human Genetics, University Hospital of Cologne, Cologne, Germany
| | - Michaela Thoenes
- Institute of Human Genetics, University Hospital of Cologne, Cologne, Germany
| | - Gudrun Nürnberg
- Cologne Center for Genomics (CCG) and Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Gabi Stern-Schneider
- Department of Cell and Matrix Biology, Institute of Zoology, Johannes Gutenberg University of Mainz, Mainz, Germany
| | - Peter Nürnberg
- Cologne Center for Genomics (CCG) and Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Srikanth Karnati
- Institute for Anatomy and Cell Biology, Justus Liebig University, Giessen, Germany
| | - Daniel Swan
- Computational Biology Group, Oxford Gene Technology, Oxford, United Kingdom
| | - Ekram Fateen
- Department of Biochemical Genetics, Human Genetics and Genome Research Division, National Research Centre, Cairo, Egypt
| | - Kerstin Nagel-Wolfrum
- Department of Cell and Matrix Biology, Institute of Zoology, Johannes Gutenberg University of Mainz, Mainz, Germany
| | - Mostafa I Mostafa
- Department of Orodental Genetics, Orodental Research Division, National Research Centre, Cairo, Egypt
| | - Holger Thiele
- Cologne Center for Genomics (CCG) and Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Uwe Wolfrum
- Department of Cell and Matrix Biology, Institute of Zoology, Johannes Gutenberg University of Mainz, Mainz, Germany
| | | | - Hanno J Bolz
- Institute of Human Genetics, University Hospital of Cologne, Cologne, Germany.,Bioscientia Center for Human Genetics, Ingelheim, Germany
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Hilgert N, Kahrizi K, Dieltjens N, Bazazzadegan N, Najmabadi H, Smith RJH, Van Camp G. A large deletion in GPR98 causes type IIC Usher syndrome in male and female members of an Iranian family. J Med Genet 2009; 46:272-6. [PMID: 19357116 DOI: 10.1136/jmg.2008.060947] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
BACKGROUND Usher syndrome (USH) is a clinically and genetically heterogeneous disease. The three recognised clinical phenotypes (types I, II and III; USH1, USH2 and USH3) are caused by mutations in nine different genes. USH2C is characterised by moderate to severe hearing loss, retinitis pigmentosa and normal vestibular function. One earlier report describes mutations in GPR98 (VLGR1) in four families segregating this phenotype. OBJECTIVE To detect the disease-causing mutation in an Iranian family segregating USH2C. In this family, five members had a phenotype compatible with Usher syndrome, and two others had nonsyndromic hearing loss. METHODS Mutation analysis of all 90 coding exons of GPR98. RESULTS Consistent with these clinical findings, the five subjects with USH carried a haplotype linked to the USH2C locus, whereas the two subjects with nonsyndromic hearing loss did not. We identified a new mutation in GPR98 segregating with USH2C in this family. The mutation is a large deletion g.371657_507673del of exons 84 and 85, presumably leading to a frameshift. CONCLUSIONS A large GPR98 deletion of 136 017 bp segregates with USH2C in an Iranian family. To our knowledge, this is only the second report of a GPR98 mutation, and the first report on male subjects with USH2C and a GPR98 mutation.
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Affiliation(s)
- N Hilgert
- Department of Medical Genetics, University of Antwerp, Universiteitsplein 1, B-2610 Antwerp, Belgium
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Ben Rebeh I, Benzina Z, Dhouib H, Hadjamor I, Amyere M, Ayadi L, Turki K, Hammami B, Kmiha N, Kammoun H, Hakim B, Charfedine I, Vikkula M, Ghorbel A, Ayadi H, Masmoudi S. Identification of candidate regions for a novel Usher syndrome type II locus. Mol Vis 2008; 14:1719-26. [PMID: 18806881 PMCID: PMC2538493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2008] [Accepted: 09/04/2008] [Indexed: 11/30/2022] Open
Abstract
PURPOSE Chronic diseases affecting the inner ear and the retina cause severe impairments to our communication systems. In more than half of the cases, Usher syndrome (USH) is the origin of these double defects. Patients with USH type II (USH2) have retinitis pigmentosa (RP) that develops during puberty, moderate to severe hearing impairment with downsloping pure-tone audiogram, and normal vestibular function. Four loci and three genes are known for USH2. In this study, we proposed to localize the gene responsible for USH2 in a consanguineous family of Tunisian origin. METHODS Affected members underwent detailed ocular and audiologic characterization. One Tunisian family with USH2 and 45 healthy controls unrelated to the family were recruited. Two affected and six unaffected family members attended our study. DNA samples of eight family members were genotyped with polymorphic markers. Two-point and multipoint LOD scores were calculated using Genehunter software v2.1. Sequencing was used to investigate candidate genes. RESULTS Haplotype analysis showed no significant linkage to any known USH gene or locus. A genome-wide screen, using microsatellite markers, was performed, allowing the identification of three homozygous regions in chromosomes 2, 4, and 15. We further confirmed and refined these three regions using microsatellite and single-nucleotide polymorphisms. With recessive mode of inheritance, the highest multipoint LOD score of 1.765 was identified for the candidate regions on chromosomes 4 and 15. The chromosome 15 locus is large (55 Mb), underscoring the limited number of meioses in the consanguineous pedigree. Moreover, the linked, homozygous chromosome 15q alleles, unlike those of the chromosome 2 and 4 loci, are infrequent in the local population. Thus, the data strongly suggest that the novel locus for USH2 is likely to reside on 15q. CONCLUSIONS Our data provide a basis for the localization and the identification of a novel gene implicated in USH2, most likely localized on 15q.
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Affiliation(s)
- Imen Ben Rebeh
- Unité Cibles pour le Diagnostic et la Thérapie, Centre de Biotechnologie de Sfax, Tunisie
| | - Zeineb Benzina
- Service d’Ophtalmologie, C.H.U. H. Bourguiba de Sfax, Tunisie
| | - Houria Dhouib
- Service d'O.R.L., C.H.U.H. Bourguiba de Sfax, Tunisie
| | - Imen Hadjamor
- Unité Cibles pour le Diagnostic et la Thérapie, Centre de Biotechnologie de Sfax, Tunisie
| | - Mustapha Amyere
- Human Molecular Genetics, de Duve Institute, Université Catholique de Louvain, Brussels, Belgium
| | - Leila Ayadi
- Unité Cibles pour le Diagnostic et la Thérapie, Centre de Biotechnologie de Sfax, Tunisie
| | - Khalil Turki
- Service d’Ophtalmologie, C.H.U. H. Bourguiba de Sfax, Tunisie
| | | | | | - Hassen Kammoun
- Laboratoire de Génétique Moléculaire Humaine, Faculté de Médecine de Sfax, Tunisie
| | - Bochra Hakim
- Unité Cibles pour le Diagnostic et la Thérapie, Centre de Biotechnologie de Sfax, Tunisie
| | | | - Miikka Vikkula
- Human Molecular Genetics, de Duve Institute, Université Catholique de Louvain, Brussels, Belgium
| | | | - Hammadi Ayadi
- Unité Cibles pour le Diagnostic et la Thérapie, Centre de Biotechnologie de Sfax, Tunisie
| | - Saber Masmoudi
- Unité Cibles pour le Diagnostic et la Thérapie, Centre de Biotechnologie de Sfax, Tunisie
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Usher syndrome: animal models, retinal function of Usher proteins, and prospects for gene therapy. Vision Res 2007; 48:433-41. [PMID: 17936325 DOI: 10.1016/j.visres.2007.08.015] [Citation(s) in RCA: 134] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2007] [Revised: 08/22/2007] [Accepted: 08/23/2007] [Indexed: 02/07/2023]
Abstract
Usher syndrome is a deafness-blindness disorder. The blindness occurs from a progressive retinal degeneration that begins after deafness and after the retina has developed. Three clinical subtypes of Usher syndrome have been identified, with mutations in any one of six different genes giving rise to type 1, in any one of three different genes to type 2, and in one identified gene causing Usher type 3. Mutant mice for most of the genes have been studied; while they have clear inner ear defects, retinal phenotypes are relatively mild and have been difficult to characterize. The retinal functions of the Usher proteins are still largely unknown. Protein binding studies have suggested many interactions among the proteins, and a model of interaction among all the proteins in the photoreceptor synapse has been proposed. However this model is not supported by localization data from some laboratories, or the indication of any synaptic phenotype in mutant mice. An earlier suggestion, based on patient pathologies, of Usher protein function in the photoreceptor cilium continues to gain support from immunolocalization and mutant mouse studies, which are consistent with Usher protein interaction in the photoreceptor ciliary/periciliary region. So far, the most characterized Usher protein is myosin VIIa. It is present in the apical RPE and photoreceptor ciliary/periciliary region, where it is required for organelle transport and clearance of opsin from the connecting cilium, respectively. Usher syndrome is amenable to gene replacement therapy, but also has some specific challenges. Progress in this treatment approach has been achieved by correction of mutant phenotypes in Myo7a-null mouse retinas, following lentiviral delivery of MYO7A.
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Malekpour M, Shahidi A, Khorsandi Ashtiani MT, Motasaddi Zarandy M. Novel syndrome of cataracts, retinitis pigmentosa, late onset deafness and sperm abnormalities: a new Usher syndrome subtype with X-linked inheritance? Am J Med Genet A 2007; 143A:1646-52. [PMID: 17431906 DOI: 10.1002/ajmg.a.31716] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Tissues of the auditory, ocular and reproductive systems have some similarities in their protein families and structures. Consequently, syndromes comprising these systems are described. Hearing loss alone is a component of more than 400 known syndromes and is a common nonsyndromic congenital disorder. Here we describe a syndrome in five brothers with the distinctive presentation of late-onset progressive hearing loss, cataracts, retinitis pigmentosa, sperm motility and shape problems in a family from the Kurdish population in Iran. The clinical findings of these patients are presented in detail and compared to the classical Usher syndromes.
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Affiliation(s)
- Mahdi Malekpour
- ENT Research Center, Department of Otolaryngology, Head and Neck Surgery, Amir Alam Hospital, Tehran University of Medical Sciences, Tehran, Iran
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Abstract
BACKGROUND Usher syndrome is a genetic disorder consisting of progressive loss of vision and hearing. CASE REPORT The paper describes an 8-year-old girl with Usher syndrome type I who presented with generalized defects of the permanent dentition and ectopic eruption of the right maxillary first permanent molar. A cochlear implant had been fitted for her hearing loss, and the report reviews the implications of this device for dental treatment. The impacted first permanent molar was encouraged to erupt into the correct position by shaving the distal surface of the second primary molar. CONCLUSION This is the first report to describe in detail an association between Usher syndrome and enamel defects.
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Affiliation(s)
- Richard Balmer
- Division Child Dental Health, Leeds Dental Institute, Leeds, UK.
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Kimberling WJ. Estimation of the frequency of occult mutations for an autosomal recessive disease in the presence of genetic heterogeneity: application to genetic hearing loss disorders. Hum Mutat 2006; 26:462-70. [PMID: 16145690 DOI: 10.1002/humu.20221] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The routine testing for pathologic mutation(s) in a patient's DNA has become the foundation of modern molecular genetic diagnosis. It is especially valuable when the phenotype shows genetic heterogeneity, and its importance will grow as treatments become genotype specific. However, the technology of mutation detection is imperfect and mutations are often missed. This can be especially troublesome when dealing with a recessive disorder where the combination of genetic heterogeneity and missed mutation creates an imprecision in the genotypic assessment of individuals who do not appear to have the expected complement of two pathologic mutations. This article describes a statistical approach to the estimation of the likelihood of a genetic diagnosis under these conditions. In addition to providing a means of testing for missed mutations, it also provides a method of estimating and testing for the presence of genetic heterogeneity in the absence of linkage data. Gene frequencies as well as estimates of sensitivity and specificity can be obtained as well. The test is applied to GJB2 recessive nonsyndromic deafness, Usher syndrome types Ib and IIa, and Pendred-enlarged vestibular aqueduct syndrome.
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Affiliation(s)
- William J Kimberling
- Center for the Study and Treatment of Usher Syndrome, Boys Town National Research Hospital and the Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, Nebraska 68131, USA.
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Weleber RG, Gregory-Evans K. Retinitis Pigmentosa and Allied Disorders. Retina 2006. [DOI: 10.1016/b978-0-323-02598-0.50023-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
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Adato A, Lefèvre G, Delprat B, Michel V, Michalski N, Chardenoux S, Weil D, El-Amraoui A, Petit C. Usherin, the defective protein in Usher syndrome type IIA, is likely to be a component of interstereocilia ankle links in the inner ear sensory cells. Hum Mol Genet 2005; 14:3921-32. [PMID: 16301217 DOI: 10.1093/hmg/ddi416] [Citation(s) in RCA: 139] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Usher syndrome type IIa (USH2A) combines moderate to severe congenital hearing impairment and retinitis pigmentosa. It is the most common genetic form of USH. USH2A encodes usherin, which was previously defined as a basement membrane protein. A much larger USH2A transcript predicted to encode a transmembrane (TM) isoform was recently reported. Here, we address the role of TM usherin in the inner ear. Analysis of the usherin alternative transcripts in the murine inner ear revealed the existence of several predicted TM usherin isoforms with modular ectodomains of different lengths. In addition, we identified in the usherin cytoplasmic region a predicted 24 amino acid peptide, derived from a newly defined exon that is predominantly expressed in the inner ear but not in the retina. In mouse and rat inner ears, we show that TM usherin is present at the base of the differentiating stereocilia, which make up the mechanosensitive hair bundles receptive to sound. The usherin immunolabeling is transient in the hair bundles of cochlear hair cells (HCs), but persists in mature hair bundles of vestibular HCs. Several lines of evidence support the involvement of TM usherin in the composition of the ankle links, a subset of filamentous lateral links connecting stereocilia at the base. By co-immunoprecipitation and in vitro binding assays, we establish that the usherin cytodomain can bind to whirlin and harmonin, two PDZ domain-containing proteins that are defective in genetic forms of isolated deafness and USH type I, respectively. These PDZ proteins are suitable to provide the anchoring of interstereocilia lateral links to the F-actin core of stereocilia. Our results strongly suggest that congenital deafness in USH type I and type II shares similar pathogenic mechanisms, i.e. the disruption of hair bundle links-mediated adhesion forces that are essential for the proper organization of growing hair bundles.
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Affiliation(s)
- Avital Adato
- Unité de Génétique des Déficits Sensoriels, INSERM U587, Institut Pasteur, Paris, France
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Nájera C, Beneyto M, Millán JM. [Usher syndrome: an example of genetic heterogeneity]. Med Clin (Barc) 2005; 125:423-7. [PMID: 16216190 DOI: 10.1157/13079387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Usher syndrome includes hereditary pathologies characterized by bilateral sensorineural deafness and visual impairment due to retinitis pigmentosa. Clinically, there are three distinct subtypes referred to as USH1, USH2, and USH3. Each subtype is genetically heterogeneous. Eleven different genes are implicated in the pathology; most of them are also implicated in isolated auditory or visual pathologies. MYO7A is responsible of 75% of the USH1 cases and Usherin is responsible of 82% of USH2A patients. The proteins have direct interactions with each other, are expressed in cochlea and retina and perform an essential role in stereocilia homeostasis. From 1995 we approach the study of Usher syndrome in Spain from different points of view: epidemiological, clinic, genetic and molecular. This study will provide additional insight into the pathogenic process involved in Usher syndrome, prognosis factors, and guide to the search for targeted therapies.
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Affiliation(s)
- Carmen Nájera
- Departamento de Genética, Universitat de Valencia, Valencia, Spain.
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Abstract
Mutations in seven different genes have been associated with Usher syndrome, and an additional four loci have been mapped. The identified genes encode myosin VIIa, harmonin (a PDZ-domain protein), cadherin 23, protocadherin 15, sans (a scaffold-like protein), usherin and clarin. Three clinical types of Usher syndrome have been described: USH1 patients have severe to profound congenital hearing loss, vestibular dysfunction, and retinal degeneration beginning in childhood, those with USH2 have moderate to severe congenital hearing loss, normal vestibular function, and later onset of retinitis pigmentosa, and USH3 patients have progressive hearing loss, which distinguishes them from the other two types. The shaker-1, waltzer, Ames waltzer, and Jackson shaker mice provide murine models for four of the genetic forms of Usher syndrome. Ongoing studies are enabling early diagnosis of Usher syndrome in children who present with hearing loss, thus providing time to prepare for the onset of visual loss.
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Affiliation(s)
- Bronya J B Keats
- Department of Genetics, Louisiana State University Health Sciences Center, New Orleans, Louisiana 70112, USA.
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Ramzan K, Shaikh RS, Ahmad J, Khan SN, Riazuddin S, Ahmed ZM, Friedman TB, Wilcox ER, Riazuddin S. A new locus for nonsyndromic deafness DFNB49 maps to chromosome 5q12.3-q14.1. Hum Genet 2004; 116:17-22. [PMID: 15538632 DOI: 10.1007/s00439-004-1205-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2004] [Accepted: 09/21/2004] [Indexed: 11/24/2022]
Abstract
Cosegregation of markers on chromosome 5q12.3-q14.1 with profound congenital deafness in two Pakistani families (PKDF041 and PKDF141) defines a new recessive deafness locus, DFNB49. A maximum two-point lod score of 4.44 and 5.94 at recombination fraction theta=0 was obtained for markers D5S2055 and D5S424 in families PKDF041 and PKDF141, respectively. Haplotype analysis revealed an 11 cM linkage region flanked by markers D5S647 (74.07 cM) and D5S1501 (85.25 cM). Candidate deafness genes in this region include SLC30A5, OCLN, GTF2H2, and BTF3, encoding solute carrier family 30 (zinc transporter) member 5, occludin, RNA polymerase II transcription initiation factor, and basic transcription factor 3, respectively. Sequence analysis of the coding exons of SLC30A5 in DNA samples from two affected individuals of families PKDF041 and PKDF141 revealed no mutation. The mapping of DFNB49 further confirms the heterogeneity underlying autosomal recessive forms of nonsyndromic deafness.
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Affiliation(s)
- Khushnooda Ramzan
- National Centre of Excellence in Molecular Biology, University of the Punjab, 87-West Canal Bank Road, Thokar Niaz Baig, Lahore 53700, Pakistan
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Seyedahmadi BJ, Rivolta C, Keene JA, Berson EL, Dryja TP. Comprehensive screening of the USH2A gene in Usher syndrome type II and non-syndromic recessive retinitis pigmentosa. Exp Eye Res 2004; 79:167-73. [PMID: 15325563 DOI: 10.1016/j.exer.2004.03.005] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2003] [Accepted: 03/10/2004] [Indexed: 10/26/2022]
Abstract
A screen of the entire coding region of the USH2A gene in 129 unrelated patients with Usher syndrome type II (USH2) and in 146 unrelated patients with non-syndromic autosomal recessive retinitis pigmentosa (ARRP) uncovered 54 different sequence variations, including 18 likely pathogenic mutations (13 frameshift, three nonsense, and two missense), 12 changes of uncertain pathogenicity (11 missense changes and one in-frame deletion), and 24 non-pathogenic rare variants or polymorphisms. Of the 18 likely pathogenic mutations, nine were novel. Among the USH2 patients, 50 (39%) had one or two likely pathogenic mutations. The most common mutant allele in USH2 patients was E767fs, which was found in 29 patients, including one homozygote. Among the ARRP patients, we found 17 (12%) with one or two likely pathogenic mutations. The most common mutant allele in ARRP patients was C759F and it was found in 10 patients. The C759F allele was also found in two USH2 patients; in neither of them was a change in the other allele found. The second most common mutant allele in both patient groups was L1447fs (found in 6/50 USH2 patients and 6/17 ARRP patients). Of the 50+17=67 patients with identified USH2A mutations, only one mutation in one allele was found in 41+12=53 (79%); the reason for the high proportion of patients with only one identified mutation is obscure. Our results indicate that USH2A mutations are found in about 7% of all cases of RP in North America, a frequency similar to the RPGR gene (8%) and the rhodopsin gene (10%).
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Affiliation(s)
- Babak Jian Seyedahmadi
- Ocular Molecular Genetics Institute, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston, MA 02114, USA
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19
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Abstract
Over the past decade, there has been an exponential increase in our knowledge of heritable eye conditions. Coincidentally, our ability to provide accurate genetic diagnoses has allowed appropriate counseling to patients and families. A summary of our current understanding of ocular genetics will prove useful to clinicians, researchers, and students as an introduction to the subject.
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Affiliation(s)
- Ian M MacDonald
- Department of Ophthalmology, University of Alberta, Edmonton, Alberta, Canada
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Affiliation(s)
- R Siddiqi
- Weill Medical College of Cornell University, New York, NY 10021, USA.
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21
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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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Ouyang XM, Yan D, Hejtmancik JF, Jacobson SG, Li AR, Du LL, Angeli S, Kaiser M, Balkany T, Liu XZ. Mutational spectrum in Usher syndrome type II. Clin Genet 2004; 65:288-93. [PMID: 15025721 DOI: 10.1046/j.1399-0004.2004.00216.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Usher syndrome type II is an autosomal recessive disorder characterized by moderate to severe hearing impairment and progressive visual loss due to retinitis pigmentosa (RP). We carried out a mutation screening of the USH2A gene in 88 probands with Usher syndrome type II to determine the frequency of USH2A mutations as a cause for USH2. Six mutations, including 2299delG, 921-922insCAGC, R334W, N346H, R626X, and N357T were identified, with 2299delG mutation being the most frequent (16.5% of alleles), accounting for 77.5% of the pathologic alleles. Thirty-five percent (31/88) of the probands had a USH2A mutation. Nine of them carried two pathogenic mutations: six cases were homozygotes and three were compound heterozygotes. Twenty-two probands (25%) were found to carry only single USH2A mutations. One new missense mutation (N357T) occuring within the laminin N-terminal (type VI) domain of usherin was identified. Eight polymorphisms were found, five of which are novel. Our data support the view that the 2299delG is the most common mutation in USH2A.
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Affiliation(s)
- X M Ouyang
- Department of Otolaryngology, University of Miami, Miami, FL 33136, USA
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Weston MD, Luijendijk MWJ, Humphrey KD, Möller C, Kimberling WJ. Mutations in the VLGR1 gene implicate G-protein signaling in the pathogenesis of Usher syndrome type II. Am J Hum Genet 2004; 74:357-66. [PMID: 14740321 PMCID: PMC1181933 DOI: 10.1086/381685] [Citation(s) in RCA: 239] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2003] [Accepted: 11/20/2003] [Indexed: 11/04/2022] Open
Abstract
Usher syndrome type II (USH2) is a genetically heterogeneous autosomal recessive disorder with at least three genetic subtypes (USH2A, USH2B, and USH2C) and is classified phenotypically as congenital hearing loss and progressive retinitis pigmentosa. The VLGR1 (MASS1) gene in the 5q14.3-q21.1 USH2C locus was considered a likely candidate on the basis of its protein motif structure and expressed-sequence-tag representation from both cochlear and retinal subtracted libraries. Denaturing high-performance liquid chromatography and direct sequencing of polymerase-chain-reaction products amplified from 10 genetically independent patients with USH2C and 156 other patients with USH2 identified four isoform-specific VLGR1 mutations (Q2301X, I2906FS, M2931FS, and T6244X) from three families with USH2C, as well as two sporadic cases. All patients with VLGR1 mutations are female, a significant deviation from random expectations. The ligand(s) for the VLGR1 protein is unknown, but on the basis of its potential extracellular and intracellular protein-protein interaction domains and its wide mRNA expression profile, it is probable that VLGR1 serves diverse cellular and signaling processes. VLGR1 mutations have been previously identified in both humans and mice and are associated with a reflex-seizure phenotype in both species. The identification of additional VLGR1 mutations to test whether a phenotype/genotype correlation exists, akin to that shown for other Usher syndrome disease genes, is warranted.
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Affiliation(s)
- Michael D. Weston
- Center for the Study and Treatment of Usher Syndrome, Department of Genetics, Boys Town National Research Hospital, Omaha; Departments of Biomedical Sciences and Biology, Creighton University, Omaha; Department of Human Genetics, University Medical Center Nijmegen, Nijmegen, The Netherlands; and Department of Audiology, Sahlgrenska University Hospital, Göteborg, Sweden
| | - Mirjam W. J. Luijendijk
- Center for the Study and Treatment of Usher Syndrome, Department of Genetics, Boys Town National Research Hospital, Omaha; Departments of Biomedical Sciences and Biology, Creighton University, Omaha; Department of Human Genetics, University Medical Center Nijmegen, Nijmegen, The Netherlands; and Department of Audiology, Sahlgrenska University Hospital, Göteborg, Sweden
| | - Kurt D. Humphrey
- Center for the Study and Treatment of Usher Syndrome, Department of Genetics, Boys Town National Research Hospital, Omaha; Departments of Biomedical Sciences and Biology, Creighton University, Omaha; Department of Human Genetics, University Medical Center Nijmegen, Nijmegen, The Netherlands; and Department of Audiology, Sahlgrenska University Hospital, Göteborg, Sweden
| | - Claes Möller
- Center for the Study and Treatment of Usher Syndrome, Department of Genetics, Boys Town National Research Hospital, Omaha; Departments of Biomedical Sciences and Biology, Creighton University, Omaha; Department of Human Genetics, University Medical Center Nijmegen, Nijmegen, The Netherlands; and Department of Audiology, Sahlgrenska University Hospital, Göteborg, Sweden
| | - William J. Kimberling
- Center for the Study and Treatment of Usher Syndrome, Department of Genetics, Boys Town National Research Hospital, Omaha; Departments of Biomedical Sciences and Biology, Creighton University, Omaha; Department of Human Genetics, University Medical Center Nijmegen, Nijmegen, The Netherlands; and Department of Audiology, Sahlgrenska University Hospital, Göteborg, Sweden
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Abstract
Association of sensorineural deafness and progressive retinitis pigmentosa with and without a vestibular abnormality is the hallmark of Usher syndrome and involves at least 12 loci among three different clinical subtypes. Genes identified for the more commonly inherited loci are USH2A (encoding usherin), MYO7A (encoding myosin VIIa), CDH23 (encoding cadherin 23), PCDH15 (encoding protocadherin 15), USH1C (encoding harmonin), USH3A (encoding clarin 1), and USH1G (encoding SANS). Transcripts from all these genes are found in many tissues/cell types other than the inner ear and retina, but all are uniquely critical for retinal and cochlear cell function. Many of these protein products have been demonstrated to have direct interactions with each other and perform an essential role in stereocilia homeostasis.
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Affiliation(s)
- Z M Ahmed
- National Center of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
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Pearsall N, Bhattacharya G, Wisecarver J, Adams J, Cosgrove D, Kimberling W. Usherin expression is highly conserved in mouse and human tissues. Hear Res 2002; 174:55-63. [PMID: 12433396 DOI: 10.1016/s0378-5955(02)00635-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Usher syndrome is an autosomal recessive disease that results in varying degrees of hearing loss and retinitis pigmentosa. Three types of Usher syndrome (I, II, and III) have been identified clinically with Usher type II being the most common of the three types. Usher type II has been localized to three different chromosomes 1q41, 3p, and 5q, corresponding to Usher type 2A, 2B, and 2C respectively. Usherin is a basement membrane protein encoded by the USH2A gene. Expression of usherin has been localized in the basement membrane of several tissues, however it is not ubiquitous. Immunohistochemistry detected usherin in the following human tissues: retina, cochlea, small and large intestine, pancreas, bladder, prostate, esophagus, trachea, thymus, salivary glands, placenta, ovary, fallopian tube, uterus, and testis. Usherin was absent in many other tissues such as heart, lung, liver, kidney, and brain. This distribution is consistent with the usherin distribution seen in the mouse. Conservation of usherin is also seen at the nucleotide and amino acid level when comparing the mouse and human gene sequences. Evolutionary conservation of usherin expression at the molecular level and in tissues unaffected by Usher 2a supports the important structural and functional role this protein plays in the human. In addition, we believe that these results could lead to a diagnostic procedure for the detection of Usher syndrome and those who carry an USH2A mutation.
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Affiliation(s)
- Nicole Pearsall
- Boys Town National Research Hospital, 555 No. 30th St., Omaha, NE, USA
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Staub E, Pérez-Tur J, Siebert R, Nobile C, Moschonas NK, Deloukas P, Hinzmann B. The novel EPTP repeat defines a superfamily of proteins implicated in epileptic disorders. Trends Biochem Sci 2002; 27:441-4. [PMID: 12217514 DOI: 10.1016/s0968-0004(02)02163-1] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Recent studies suggest that mutations in the LGI1/Epitempin gene cause autosomal dominant lateral temporal epilepsy. This gene encodes a protein of unknown function, which we postulate is secreted. The LGI1 protein has leucine-rich repeats in the N-terminal sequence and a tandem repeat (which we named EPTP) in its C-terminal region. A redefinition of the C-terminal repeat and the application of sensitive sequence analysis methods enabled us to define a new superfamily of proteins carrying varying numbers of the novel EPTP repeats in combination with various extracellular domains. Genes encoding proteins of this family are located in genomic regions associated with epilepsy and other neurological disorders.
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Affiliation(s)
- Eike Staub
- metaGen Pharmaceuticals GmbH, Oudenarder Strasse 16, D-13347 Berlin, Germany.
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27
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Adato A, Vreugde S, Joensuu T, Avidan N, Hamalainen R, Belenkiy O, Olender T, Bonne-Tamir B, Ben-Asher E, Espinos C, Millán JM, Lehesjoki AE, Flannery JG, Avraham KB, Pietrokovski S, Sankila EM, Beckmann JS, Lancet D. USH3A transcripts encode clarin-1, a four-transmembrane-domain protein with a possible role in sensory synapses. Eur J Hum Genet 2002; 10:339-50. [PMID: 12080385 DOI: 10.1038/sj.ejhg.5200831] [Citation(s) in RCA: 128] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2002] [Revised: 04/26/2002] [Accepted: 05/01/2002] [Indexed: 11/09/2022] Open
Abstract
Usher syndrome type 3 (USH3) is an autosomal recessive disorder characterised by the association of post-lingual progressive hearing loss, progressive visual loss due to retinitis pigmentosa and variable presence of vestibular dysfunction. Because the previously defined transcripts do not account for all USH3 cases, we performed further analysis and revealed the presence of additional exons embedded in longer human and mouse USH3A transcripts and three novel USH3A mutations. Expression of Ush3a transcripts was localised by whole mount in situ hybridisation to cochlear hair cells and spiral ganglion cells. The full length USH3A transcript encodes clarin-1, a four-transmembrane-domain protein, which defines a novel vertebrate-specific family of three paralogues. Limited sequence homology to stargazin, a cerebellar synapse four-transmembrane-domain protein, suggests a role for clarin-1 in hair cell and photoreceptor cell synapses, as well as a common pathophysiological pathway for different Usher syndromes.
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Affiliation(s)
- Avital Adato
- Department of Molecular Genetics and The Crown Human Genome Center, The Weizmann Institute of Science, Rehovot, 76100, Israel.
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Tsilou ET, Rubin BI, Caruso RC, Reed GF, Pikus A, Hejtmancik JF, Iwata F, Redman JB, Kaiser-Kupfer MI. Usher syndrome clinical types I and II: could ocular symptoms and signs differentiate between the two types? ACTA OPHTHALMOLOGICA SCANDINAVICA 2002; 80:196-201. [PMID: 11952489 DOI: 10.1034/j.1600-0420.2002.800215.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
PURPOSE Usher syndrome types I and II are clinical syndromes with substantial genetic and clinical heterogeneity. We undertook the current study in order to identify ocular symptoms and signs that could differentiate between the two types. METHODS Sixty-seven patients with Usher syndrome were evaluated. Based on audiologic and vestibular findings, patients were classified as either Usher type I or II. The severity of the ocular signs and symptoms present in each type were compared. RESULTS Visual acuity, visual field area, electroretinographic amplitude, incidence of cataract and macular lesions were not significantly different between Usher types I and II. However, the ages when night blindness was perceived and retinitis pigmentosa was diagnosed differed significantly between the two types. CONCLUSIONS There seems to be some overlap between types I and II of Usher syndrome in regard to the ophthalmologic findings. However, night blindness appears earlier in Usher type I (although the difference in age of appearance appears to be less dramatic than previously assumed). Molecular elucidation of Usher syndrome may serve as a key to understanding these differences and, perhaps, provide a better tool for use in clinical diagnosis, prognosis and genetic counseling.
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Affiliation(s)
- Ekaterini T Tsilou
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland 20892, USA.
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29
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Abstract
Usher syndrome (USH) is defined by the association of sensorineural deafness and visual impairment due to retinitis pigmentosa. The syndrome has three distinct clinical subtypes, referred to as USH1, USH2, and USH3. Each subtype is genetically heterogeneous, and 12 loci have been detected so far. Four genes have been identified, namely, USH1B, USH1C, USH1D, and USH2A. USH1B, USH1C, and USH1D encode an unconventional myosin (myosin VIIA), a PDZ domain-containing protein (harmonin), and a cadherin-like protein (cadherin-23), respectively. Mutations of these genes cause primary defects of the sensory cells in the inner ear, and probably also in the retina. In the inner ear, the USH1 genes, I propose, are involved in the same signaling pathway, which may control development and/or maintenance of the hair bundles of sensory cells via an adhesion force (a) at the junctions between these cells and supporting cells and (b) at the level of the lateral links that interconnect the stereocilia. In contrast, the molecular pathogenesis of USH2A, which is owing to a defect of a novel extracellular matrix protein, is likely to be different from that of USH1.
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Affiliation(s)
- C Petit
- Unité de Génétique des Déficits Sensoriels, CNRS URA 1968 Institut Pasteur, Paris, Cedex 15, 75724 France.
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Bhattacharya G, Miller C, Kimberling WJ, Jablonski MM, Cosgrove D. Localization and expression of usherin: a novel basement membrane protein defective in people with Usher's syndrome type IIa. Hear Res 2002; 163:1-11. [PMID: 11788194 DOI: 10.1016/s0378-5955(01)00344-6] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
People with Usher's syndrome type IIa have mutations in a novel gene encoding a protein with domains commonly found in many types of extracellular matrix and cell surface receptor proteins. Here we report that this protein, which we refer to as usherin, is a new basement membrane protein. In the mouse, usherin has a broad, but not ubiquitous, tissue distribution. Usherin is found in all of the capillary and structural basement membranes of the human and mouse retina and in the murine inner ear at both post-natal day 0 and in the adult. High levels of usherin are also observed in tissues not affected in Usher's syndrome type IIa, including spleen, testis, oviduct, epididymis, submaxillary gland, and large and small intestines. Many organs are completely devoid of usherin, including the brain, skin, kidney, lung, liver, and skeletal muscle. Expression was observed in the smooth muscle of the small intestine, colon, and oviduct, however, usherin is not present in cardiac smooth muscle. Usherin is critical for normal development and tissue homeostasis in the inner ear and retina, illustrating yet another example of the importance of basement membranes in the development and function of tissues.
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31
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Leroy BP, Aragon-Martin JA, Weston MD, Bessant DA, Willis C, Webster AR, Bird AC, Kimberling WJ, Payne AM, Bhattacharya SS. Spectrum of mutations in USH2A in British patients with Usher syndrome type II. Exp Eye Res 2001; 72:503-9. [PMID: 11311042 DOI: 10.1006/exer.2000.0978] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Usher syndrome (USH) is a combination of a progressive pigmentary retinopathy, indistinguishable from retinitis pigmentosa, and some degree of sensorineural hearing loss. USH can be subdivided in Usher type I (USHI), type II (USHII) and type III (USHIII), all of which are inherited as autosomal recessive traits. The three subtypes are genetically heterogeneous, with six loci so far identified for USHI, three for USHII and only one for USHIII. Mutations in a novel gene, USH2A, encoding the protein usherin, have recently been shown to be associated with USHII. The gene encodes a protein with partial sequence homology to both laminin epidermal growth factor and fibronectin motifs. We analysed 35 British and one Pakistani Usher type II families with at least one affected member, for sequence changes in the 20 translated exons of the USH2A gene, using heteroduplex analysis and sequencing. Probable disease-causing mutations in USH2A were identified in 15 of 36 (41.7%) Usher II families. The most frequently encountered mutation (11/15 families or 11/18 mutated alleles) was del2299G in exon 13, resulting in a frameshift and premature stop codon. Other mutations include insertions and point mutations, of which two are previously unreported. Five different polymorphisms were also detected. Our results indicate that mutations in this gene are responsible for disease in a large proportion of British Usher type II patients. Moreover, if screening for mutations in USH2A is considered, it is sensible to screen for the del2299G mutation first.
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Affiliation(s)
- B P Leroy
- Department of Molecular Genetics, Institute of Ophthalmology, London, UK.
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32
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Otterstedde CR, Spandau U, Blankenagel A, Kimberling WJ, Reisser C. A new clinical classification for Usher's syndrome based on a new subtype of Usher's syndrome type I. Laryngoscope 2001; 111:84-6. [PMID: 11192904 DOI: 10.1097/00005537-200101000-00014] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES Usher's syndrome is an autosomal recessive disorder characterized by sensorineural hearing loss and progressive visual loss secondary to retinitis pigmentosa. Usher's syndrome is both clinically and genetically heterogeneous. Three clinical types are known today. METHODS We conducted a study on 74 patients with Usher's syndrome, performing complete audiological and neurotological examinations. RESULTS Twenty-six patients had total profound hearing loss and retinitis pigmentosa (Usher's syndrome type I), and 48 patients had moderate to severe sensorineural hearing loss and retinitis pigmentosa (Usher's syndrome type II). We identified 9 of the 26 Usher's syndrome patients with profound hearing loss who showed a normal response to bithermal vestibular testing. CONCLUSIONS The combination of profound hearing loss and normal response to bithermal vestibular testing has not been previously described in Usher's syndrome. Therefore we describe a new subtype of Usher's syndrome type I and suggest a modified clinical classification for Usher's syndrome.
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Affiliation(s)
- C R Otterstedde
- Department of Otolaryngology-Head and Neck Surgery, University of Heidelberg, Germany
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33
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Astuto LM, Weston MD, Carney CA, Hoover DM, Cremers CWRJ, Wagenaar M, Moller C, Smith RJH, Pieke-Dahl S, Greenberg J, Ramesar R, Jacobson SG, Ayuso C, Heckenlively JR, Tamayo M, Gorin MB, Reardon W, Kimberling WJ. Genetic heterogeneity of Usher syndrome: analysis of 151 families with Usher type I. Am J Hum Genet 2000; 67:1569-74. [PMID: 11060213 PMCID: PMC1287932 DOI: 10.1086/316889] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2000] [Accepted: 10/11/2000] [Indexed: 11/03/2022] Open
Abstract
Usher syndrome type I is an autosomal recessive disorder marked by hearing loss, vestibular areflexia, and retinitis pigmentosa. Six Usher I genetic subtypes at loci USH1A-USH1F have been reported. The MYO7A gene is responsible for USH1B, the most common subtype. In our analysis, 151 families with Usher I were screened by linkage and mutation analysis. MYO7A mutations were identified in 64 families with Usher I. Of the remaining 87 families, who were negative for MYO7A mutations, 54 were informative for linkage analysis and were screened with the remaining USH1 loci markers. Results of linkage and heterogeneity analyses showed no evidence of Usher types Ia or Ie. However, one maximum LOD score was observed lying within the USH1D region. Two lesser peak LOD scores were observed outside and between the putative regions for USH1D and USH1F, on chromosome 10. A HOMOG chi(2)((1)) plot shows evidence of heterogeneity across the USH1D, USH1F, and intervening regions. These results provide conclusive evidence that the second-most-common subtype of Usher I is due to genes on chromosome 10, and they confirm the existence of one Usher I gene in the previously defined USH1D region, as well as providing evidence for a second, and possibly a third, gene in the 10p/q region.
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Affiliation(s)
- Lisa M. Astuto
- Center for Hereditary Communication Disorders, Boys Town National Research Hospital, Omaha; Department of Otorhinolaryngology, University Hospital, Nijmegen, the Netherlands; Department of Audiology, Sahlgrenska University Hospital, Gothenburg, Sweden; Department of Otolaryngology, University of Iowa, Iowa City; Department of Human Genetics, University of Cape Town Medical School, Cape Town; Department of Ophthalmology, Scheie Eye Institute, Philadelphia; Fundacion Jimenez Diaz, Madrid, Spain; Jules Stein Eye Institute, University of California at Los Angeles School of Medicine, Los Angeles; Instituto de Genetica Humana, Universidad Javeriana, Bogota, Colombia; Departments of Ophthalmology and Human Genetics, University of Pittsburgh, Pittsburgh; Institute of Child Health, University of London, London
| | - Michael D. Weston
- Center for Hereditary Communication Disorders, Boys Town National Research Hospital, Omaha; Department of Otorhinolaryngology, University Hospital, Nijmegen, the Netherlands; Department of Audiology, Sahlgrenska University Hospital, Gothenburg, Sweden; Department of Otolaryngology, University of Iowa, Iowa City; Department of Human Genetics, University of Cape Town Medical School, Cape Town; Department of Ophthalmology, Scheie Eye Institute, Philadelphia; Fundacion Jimenez Diaz, Madrid, Spain; Jules Stein Eye Institute, University of California at Los Angeles School of Medicine, Los Angeles; Instituto de Genetica Humana, Universidad Javeriana, Bogota, Colombia; Departments of Ophthalmology and Human Genetics, University of Pittsburgh, Pittsburgh; Institute of Child Health, University of London, London
| | - Carol A. Carney
- Center for Hereditary Communication Disorders, Boys Town National Research Hospital, Omaha; Department of Otorhinolaryngology, University Hospital, Nijmegen, the Netherlands; Department of Audiology, Sahlgrenska University Hospital, Gothenburg, Sweden; Department of Otolaryngology, University of Iowa, Iowa City; Department of Human Genetics, University of Cape Town Medical School, Cape Town; Department of Ophthalmology, Scheie Eye Institute, Philadelphia; Fundacion Jimenez Diaz, Madrid, Spain; Jules Stein Eye Institute, University of California at Los Angeles School of Medicine, Los Angeles; Instituto de Genetica Humana, Universidad Javeriana, Bogota, Colombia; Departments of Ophthalmology and Human Genetics, University of Pittsburgh, Pittsburgh; Institute of Child Health, University of London, London
| | - Denise M. Hoover
- Center for Hereditary Communication Disorders, Boys Town National Research Hospital, Omaha; Department of Otorhinolaryngology, University Hospital, Nijmegen, the Netherlands; Department of Audiology, Sahlgrenska University Hospital, Gothenburg, Sweden; Department of Otolaryngology, University of Iowa, Iowa City; Department of Human Genetics, University of Cape Town Medical School, Cape Town; Department of Ophthalmology, Scheie Eye Institute, Philadelphia; Fundacion Jimenez Diaz, Madrid, Spain; Jules Stein Eye Institute, University of California at Los Angeles School of Medicine, Los Angeles; Instituto de Genetica Humana, Universidad Javeriana, Bogota, Colombia; Departments of Ophthalmology and Human Genetics, University of Pittsburgh, Pittsburgh; Institute of Child Health, University of London, London
| | - Cor W. R. J. Cremers
- Center for Hereditary Communication Disorders, Boys Town National Research Hospital, Omaha; Department of Otorhinolaryngology, University Hospital, Nijmegen, the Netherlands; Department of Audiology, Sahlgrenska University Hospital, Gothenburg, Sweden; Department of Otolaryngology, University of Iowa, Iowa City; Department of Human Genetics, University of Cape Town Medical School, Cape Town; Department of Ophthalmology, Scheie Eye Institute, Philadelphia; Fundacion Jimenez Diaz, Madrid, Spain; Jules Stein Eye Institute, University of California at Los Angeles School of Medicine, Los Angeles; Instituto de Genetica Humana, Universidad Javeriana, Bogota, Colombia; Departments of Ophthalmology and Human Genetics, University of Pittsburgh, Pittsburgh; Institute of Child Health, University of London, London
| | - Mariette Wagenaar
- Center for Hereditary Communication Disorders, Boys Town National Research Hospital, Omaha; Department of Otorhinolaryngology, University Hospital, Nijmegen, the Netherlands; Department of Audiology, Sahlgrenska University Hospital, Gothenburg, Sweden; Department of Otolaryngology, University of Iowa, Iowa City; Department of Human Genetics, University of Cape Town Medical School, Cape Town; Department of Ophthalmology, Scheie Eye Institute, Philadelphia; Fundacion Jimenez Diaz, Madrid, Spain; Jules Stein Eye Institute, University of California at Los Angeles School of Medicine, Los Angeles; Instituto de Genetica Humana, Universidad Javeriana, Bogota, Colombia; Departments of Ophthalmology and Human Genetics, University of Pittsburgh, Pittsburgh; Institute of Child Health, University of London, London
| | - Claes Moller
- Center for Hereditary Communication Disorders, Boys Town National Research Hospital, Omaha; Department of Otorhinolaryngology, University Hospital, Nijmegen, the Netherlands; Department of Audiology, Sahlgrenska University Hospital, Gothenburg, Sweden; Department of Otolaryngology, University of Iowa, Iowa City; Department of Human Genetics, University of Cape Town Medical School, Cape Town; Department of Ophthalmology, Scheie Eye Institute, Philadelphia; Fundacion Jimenez Diaz, Madrid, Spain; Jules Stein Eye Institute, University of California at Los Angeles School of Medicine, Los Angeles; Instituto de Genetica Humana, Universidad Javeriana, Bogota, Colombia; Departments of Ophthalmology and Human Genetics, University of Pittsburgh, Pittsburgh; Institute of Child Health, University of London, London
| | - Richard J. H. Smith
- Center for Hereditary Communication Disorders, Boys Town National Research Hospital, Omaha; Department of Otorhinolaryngology, University Hospital, Nijmegen, the Netherlands; Department of Audiology, Sahlgrenska University Hospital, Gothenburg, Sweden; Department of Otolaryngology, University of Iowa, Iowa City; Department of Human Genetics, University of Cape Town Medical School, Cape Town; Department of Ophthalmology, Scheie Eye Institute, Philadelphia; Fundacion Jimenez Diaz, Madrid, Spain; Jules Stein Eye Institute, University of California at Los Angeles School of Medicine, Los Angeles; Instituto de Genetica Humana, Universidad Javeriana, Bogota, Colombia; Departments of Ophthalmology and Human Genetics, University of Pittsburgh, Pittsburgh; Institute of Child Health, University of London, London
| | - Sandra Pieke-Dahl
- Center for Hereditary Communication Disorders, Boys Town National Research Hospital, Omaha; Department of Otorhinolaryngology, University Hospital, Nijmegen, the Netherlands; Department of Audiology, Sahlgrenska University Hospital, Gothenburg, Sweden; Department of Otolaryngology, University of Iowa, Iowa City; Department of Human Genetics, University of Cape Town Medical School, Cape Town; Department of Ophthalmology, Scheie Eye Institute, Philadelphia; Fundacion Jimenez Diaz, Madrid, Spain; Jules Stein Eye Institute, University of California at Los Angeles School of Medicine, Los Angeles; Instituto de Genetica Humana, Universidad Javeriana, Bogota, Colombia; Departments of Ophthalmology and Human Genetics, University of Pittsburgh, Pittsburgh; Institute of Child Health, University of London, London
| | - Jacquie Greenberg
- Center for Hereditary Communication Disorders, Boys Town National Research Hospital, Omaha; Department of Otorhinolaryngology, University Hospital, Nijmegen, the Netherlands; Department of Audiology, Sahlgrenska University Hospital, Gothenburg, Sweden; Department of Otolaryngology, University of Iowa, Iowa City; Department of Human Genetics, University of Cape Town Medical School, Cape Town; Department of Ophthalmology, Scheie Eye Institute, Philadelphia; Fundacion Jimenez Diaz, Madrid, Spain; Jules Stein Eye Institute, University of California at Los Angeles School of Medicine, Los Angeles; Instituto de Genetica Humana, Universidad Javeriana, Bogota, Colombia; Departments of Ophthalmology and Human Genetics, University of Pittsburgh, Pittsburgh; Institute of Child Health, University of London, London
| | - Raj Ramesar
- Center for Hereditary Communication Disorders, Boys Town National Research Hospital, Omaha; Department of Otorhinolaryngology, University Hospital, Nijmegen, the Netherlands; Department of Audiology, Sahlgrenska University Hospital, Gothenburg, Sweden; Department of Otolaryngology, University of Iowa, Iowa City; Department of Human Genetics, University of Cape Town Medical School, Cape Town; Department of Ophthalmology, Scheie Eye Institute, Philadelphia; Fundacion Jimenez Diaz, Madrid, Spain; Jules Stein Eye Institute, University of California at Los Angeles School of Medicine, Los Angeles; Instituto de Genetica Humana, Universidad Javeriana, Bogota, Colombia; Departments of Ophthalmology and Human Genetics, University of Pittsburgh, Pittsburgh; Institute of Child Health, University of London, London
| | - Samuel G. Jacobson
- Center for Hereditary Communication Disorders, Boys Town National Research Hospital, Omaha; Department of Otorhinolaryngology, University Hospital, Nijmegen, the Netherlands; Department of Audiology, Sahlgrenska University Hospital, Gothenburg, Sweden; Department of Otolaryngology, University of Iowa, Iowa City; Department of Human Genetics, University of Cape Town Medical School, Cape Town; Department of Ophthalmology, Scheie Eye Institute, Philadelphia; Fundacion Jimenez Diaz, Madrid, Spain; Jules Stein Eye Institute, University of California at Los Angeles School of Medicine, Los Angeles; Instituto de Genetica Humana, Universidad Javeriana, Bogota, Colombia; Departments of Ophthalmology and Human Genetics, University of Pittsburgh, Pittsburgh; Institute of Child Health, University of London, London
| | - Carmen Ayuso
- Center for Hereditary Communication Disorders, Boys Town National Research Hospital, Omaha; Department of Otorhinolaryngology, University Hospital, Nijmegen, the Netherlands; Department of Audiology, Sahlgrenska University Hospital, Gothenburg, Sweden; Department of Otolaryngology, University of Iowa, Iowa City; Department of Human Genetics, University of Cape Town Medical School, Cape Town; Department of Ophthalmology, Scheie Eye Institute, Philadelphia; Fundacion Jimenez Diaz, Madrid, Spain; Jules Stein Eye Institute, University of California at Los Angeles School of Medicine, Los Angeles; Instituto de Genetica Humana, Universidad Javeriana, Bogota, Colombia; Departments of Ophthalmology and Human Genetics, University of Pittsburgh, Pittsburgh; Institute of Child Health, University of London, London
| | - John R. Heckenlively
- Center for Hereditary Communication Disorders, Boys Town National Research Hospital, Omaha; Department of Otorhinolaryngology, University Hospital, Nijmegen, the Netherlands; Department of Audiology, Sahlgrenska University Hospital, Gothenburg, Sweden; Department of Otolaryngology, University of Iowa, Iowa City; Department of Human Genetics, University of Cape Town Medical School, Cape Town; Department of Ophthalmology, Scheie Eye Institute, Philadelphia; Fundacion Jimenez Diaz, Madrid, Spain; Jules Stein Eye Institute, University of California at Los Angeles School of Medicine, Los Angeles; Instituto de Genetica Humana, Universidad Javeriana, Bogota, Colombia; Departments of Ophthalmology and Human Genetics, University of Pittsburgh, Pittsburgh; Institute of Child Health, University of London, London
| | - Marta Tamayo
- Center for Hereditary Communication Disorders, Boys Town National Research Hospital, Omaha; Department of Otorhinolaryngology, University Hospital, Nijmegen, the Netherlands; Department of Audiology, Sahlgrenska University Hospital, Gothenburg, Sweden; Department of Otolaryngology, University of Iowa, Iowa City; Department of Human Genetics, University of Cape Town Medical School, Cape Town; Department of Ophthalmology, Scheie Eye Institute, Philadelphia; Fundacion Jimenez Diaz, Madrid, Spain; Jules Stein Eye Institute, University of California at Los Angeles School of Medicine, Los Angeles; Instituto de Genetica Humana, Universidad Javeriana, Bogota, Colombia; Departments of Ophthalmology and Human Genetics, University of Pittsburgh, Pittsburgh; Institute of Child Health, University of London, London
| | - Michael B. Gorin
- Center for Hereditary Communication Disorders, Boys Town National Research Hospital, Omaha; Department of Otorhinolaryngology, University Hospital, Nijmegen, the Netherlands; Department of Audiology, Sahlgrenska University Hospital, Gothenburg, Sweden; Department of Otolaryngology, University of Iowa, Iowa City; Department of Human Genetics, University of Cape Town Medical School, Cape Town; Department of Ophthalmology, Scheie Eye Institute, Philadelphia; Fundacion Jimenez Diaz, Madrid, Spain; Jules Stein Eye Institute, University of California at Los Angeles School of Medicine, Los Angeles; Instituto de Genetica Humana, Universidad Javeriana, Bogota, Colombia; Departments of Ophthalmology and Human Genetics, University of Pittsburgh, Pittsburgh; Institute of Child Health, University of London, London
| | - Willie Reardon
- Center for Hereditary Communication Disorders, Boys Town National Research Hospital, Omaha; Department of Otorhinolaryngology, University Hospital, Nijmegen, the Netherlands; Department of Audiology, Sahlgrenska University Hospital, Gothenburg, Sweden; Department of Otolaryngology, University of Iowa, Iowa City; Department of Human Genetics, University of Cape Town Medical School, Cape Town; Department of Ophthalmology, Scheie Eye Institute, Philadelphia; Fundacion Jimenez Diaz, Madrid, Spain; Jules Stein Eye Institute, University of California at Los Angeles School of Medicine, Los Angeles; Instituto de Genetica Humana, Universidad Javeriana, Bogota, Colombia; Departments of Ophthalmology and Human Genetics, University of Pittsburgh, Pittsburgh; Institute of Child Health, University of London, London
| | - William J. Kimberling
- Center for Hereditary Communication Disorders, Boys Town National Research Hospital, Omaha; Department of Otorhinolaryngology, University Hospital, Nijmegen, the Netherlands; Department of Audiology, Sahlgrenska University Hospital, Gothenburg, Sweden; Department of Otolaryngology, University of Iowa, Iowa City; Department of Human Genetics, University of Cape Town Medical School, Cape Town; Department of Ophthalmology, Scheie Eye Institute, Philadelphia; Fundacion Jimenez Diaz, Madrid, Spain; Jules Stein Eye Institute, University of California at Los Angeles School of Medicine, Los Angeles; Instituto de Genetica Humana, Universidad Javeriana, Bogota, Colombia; Departments of Ophthalmology and Human Genetics, University of Pittsburgh, Pittsburgh; Institute of Child Health, University of London, London
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34
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Weston MD, Eudy JD, Fujita S, Yao SF, Usami S, Cremers C, Greenburg J, Ramesar R, Martini A, Moller C, Smith RJ, Sumegi J, Kimberling WJ. Genomic structure and identification of novel mutations in usherin, the gene responsible for Usher syndrome type IIa. Am J Hum Genet 2000; 66:1199-210. [PMID: 10729113 PMCID: PMC1288187 DOI: 10.1086/302855] [Citation(s) in RCA: 132] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/1999] [Accepted: 01/14/2000] [Indexed: 01/11/2023] Open
Abstract
Usher syndrome type IIa (USHIIa) is an autosomal recessive disorder characterized by moderate to severe sensorineural hearing loss and progressive retinitis pigmentosa. This disorder maps to human chromosome 1q41. Recently, mutations in USHIIa patients were identified in a novel gene isolated from this chromosomal region. The USH2A gene encodes a protein with a predicted molecular weight of 171.5 kD and possesses laminin epidermal growth factor as well as fibronectin type III domains. These domains are observed in other protein components of the basal lamina and extracellular matrixes; they may also be observed in cell-adhesion molecules. The intron/exon organization of the gene whose protein we name "Usherin" was determined by direct sequencing of PCR products and cloned genomic DNA with cDNA-specific primers. The gene is encoded by 21 exons and spans a minimum of 105 kb. A mutation search of 57 independent USHIIa probands was performed with a combination of direct sequencing and heteroduplex analysis of PCR-amplified exons. Fifteen new mutations were found. Of 114 independent USH2A alleles, 58 harbored probable pathologic mutations. Ten cases of USHIIa were true homozygotes and 10 were compound heterozygotes; 18 heterozygotes with only one identifiable mutation were observed. Sixty-five percent (38/58) of cases had at least one mutation, and 51% (58/114) of the total number of possible mutations were identified. The allele 2299delG (previously reported as 2314delG) was the most frequent mutant allele observed (16%; 31/192). Three new missense mutations (C319Y, N346H, and C419F) were discovered; all were restricted to the previously unreported laminin domain VI region of Usherin. The possible significance of this domain, known to be necessary for laminin network assembly, is discussed in the context of domain VI mutations from other proteins.
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Affiliation(s)
- M. D. Weston
- Department of Genetics, Boys Town National Research Hospital, and Center for Molecular Genetics, Monroe-Meyer Institute for Genetics and Rehabilitation, University of Nebraska Medical Center, Omaha; Department of Otorhinolaryngology, Hirosaki University School of Medicine, Hirosaki, and Department of Otorhinolaryngology, Shinshu University School of Medicine, Matsumoto, Japan; Katholieke Universiteit Nijmegen, Nijmegen, The Netherlands; University of Cape Town Medical School, Department of Genetics, Cape Town, South Africa; ENT Department, Universita di Ferrara, Ferrara, Italy; Department of Audiology, Sahlgrenska University Hospital, Gotebörg, Sweden; Molecular Otolaryngology Research Laboratories, Department of Otolaryngology-Head and Neck Surgery, University of Iowa, Iowa City
| | - J. D. Eudy
- Department of Genetics, Boys Town National Research Hospital, and Center for Molecular Genetics, Monroe-Meyer Institute for Genetics and Rehabilitation, University of Nebraska Medical Center, Omaha; Department of Otorhinolaryngology, Hirosaki University School of Medicine, Hirosaki, and Department of Otorhinolaryngology, Shinshu University School of Medicine, Matsumoto, Japan; Katholieke Universiteit Nijmegen, Nijmegen, The Netherlands; University of Cape Town Medical School, Department of Genetics, Cape Town, South Africa; ENT Department, Universita di Ferrara, Ferrara, Italy; Department of Audiology, Sahlgrenska University Hospital, Gotebörg, Sweden; Molecular Otolaryngology Research Laboratories, Department of Otolaryngology-Head and Neck Surgery, University of Iowa, Iowa City
| | - S. Fujita
- Department of Genetics, Boys Town National Research Hospital, and Center for Molecular Genetics, Monroe-Meyer Institute for Genetics and Rehabilitation, University of Nebraska Medical Center, Omaha; Department of Otorhinolaryngology, Hirosaki University School of Medicine, Hirosaki, and Department of Otorhinolaryngology, Shinshu University School of Medicine, Matsumoto, Japan; Katholieke Universiteit Nijmegen, Nijmegen, The Netherlands; University of Cape Town Medical School, Department of Genetics, Cape Town, South Africa; ENT Department, Universita di Ferrara, Ferrara, Italy; Department of Audiology, Sahlgrenska University Hospital, Gotebörg, Sweden; Molecular Otolaryngology Research Laboratories, Department of Otolaryngology-Head and Neck Surgery, University of Iowa, Iowa City
| | - S.-F. Yao
- Department of Genetics, Boys Town National Research Hospital, and Center for Molecular Genetics, Monroe-Meyer Institute for Genetics and Rehabilitation, University of Nebraska Medical Center, Omaha; Department of Otorhinolaryngology, Hirosaki University School of Medicine, Hirosaki, and Department of Otorhinolaryngology, Shinshu University School of Medicine, Matsumoto, Japan; Katholieke Universiteit Nijmegen, Nijmegen, The Netherlands; University of Cape Town Medical School, Department of Genetics, Cape Town, South Africa; ENT Department, Universita di Ferrara, Ferrara, Italy; Department of Audiology, Sahlgrenska University Hospital, Gotebörg, Sweden; Molecular Otolaryngology Research Laboratories, Department of Otolaryngology-Head and Neck Surgery, University of Iowa, Iowa City
| | - S. Usami
- Department of Genetics, Boys Town National Research Hospital, and Center for Molecular Genetics, Monroe-Meyer Institute for Genetics and Rehabilitation, University of Nebraska Medical Center, Omaha; Department of Otorhinolaryngology, Hirosaki University School of Medicine, Hirosaki, and Department of Otorhinolaryngology, Shinshu University School of Medicine, Matsumoto, Japan; Katholieke Universiteit Nijmegen, Nijmegen, The Netherlands; University of Cape Town Medical School, Department of Genetics, Cape Town, South Africa; ENT Department, Universita di Ferrara, Ferrara, Italy; Department of Audiology, Sahlgrenska University Hospital, Gotebörg, Sweden; Molecular Otolaryngology Research Laboratories, Department of Otolaryngology-Head and Neck Surgery, University of Iowa, Iowa City
| | - C. Cremers
- Department of Genetics, Boys Town National Research Hospital, and Center for Molecular Genetics, Monroe-Meyer Institute for Genetics and Rehabilitation, University of Nebraska Medical Center, Omaha; Department of Otorhinolaryngology, Hirosaki University School of Medicine, Hirosaki, and Department of Otorhinolaryngology, Shinshu University School of Medicine, Matsumoto, Japan; Katholieke Universiteit Nijmegen, Nijmegen, The Netherlands; University of Cape Town Medical School, Department of Genetics, Cape Town, South Africa; ENT Department, Universita di Ferrara, Ferrara, Italy; Department of Audiology, Sahlgrenska University Hospital, Gotebörg, Sweden; Molecular Otolaryngology Research Laboratories, Department of Otolaryngology-Head and Neck Surgery, University of Iowa, Iowa City
| | - J. Greenburg
- Department of Genetics, Boys Town National Research Hospital, and Center for Molecular Genetics, Monroe-Meyer Institute for Genetics and Rehabilitation, University of Nebraska Medical Center, Omaha; Department of Otorhinolaryngology, Hirosaki University School of Medicine, Hirosaki, and Department of Otorhinolaryngology, Shinshu University School of Medicine, Matsumoto, Japan; Katholieke Universiteit Nijmegen, Nijmegen, The Netherlands; University of Cape Town Medical School, Department of Genetics, Cape Town, South Africa; ENT Department, Universita di Ferrara, Ferrara, Italy; Department of Audiology, Sahlgrenska University Hospital, Gotebörg, Sweden; Molecular Otolaryngology Research Laboratories, Department of Otolaryngology-Head and Neck Surgery, University of Iowa, Iowa City
| | - R. Ramesar
- Department of Genetics, Boys Town National Research Hospital, and Center for Molecular Genetics, Monroe-Meyer Institute for Genetics and Rehabilitation, University of Nebraska Medical Center, Omaha; Department of Otorhinolaryngology, Hirosaki University School of Medicine, Hirosaki, and Department of Otorhinolaryngology, Shinshu University School of Medicine, Matsumoto, Japan; Katholieke Universiteit Nijmegen, Nijmegen, The Netherlands; University of Cape Town Medical School, Department of Genetics, Cape Town, South Africa; ENT Department, Universita di Ferrara, Ferrara, Italy; Department of Audiology, Sahlgrenska University Hospital, Gotebörg, Sweden; Molecular Otolaryngology Research Laboratories, Department of Otolaryngology-Head and Neck Surgery, University of Iowa, Iowa City
| | - A. Martini
- Department of Genetics, Boys Town National Research Hospital, and Center for Molecular Genetics, Monroe-Meyer Institute for Genetics and Rehabilitation, University of Nebraska Medical Center, Omaha; Department of Otorhinolaryngology, Hirosaki University School of Medicine, Hirosaki, and Department of Otorhinolaryngology, Shinshu University School of Medicine, Matsumoto, Japan; Katholieke Universiteit Nijmegen, Nijmegen, The Netherlands; University of Cape Town Medical School, Department of Genetics, Cape Town, South Africa; ENT Department, Universita di Ferrara, Ferrara, Italy; Department of Audiology, Sahlgrenska University Hospital, Gotebörg, Sweden; Molecular Otolaryngology Research Laboratories, Department of Otolaryngology-Head and Neck Surgery, University of Iowa, Iowa City
| | - C. Moller
- Department of Genetics, Boys Town National Research Hospital, and Center for Molecular Genetics, Monroe-Meyer Institute for Genetics and Rehabilitation, University of Nebraska Medical Center, Omaha; Department of Otorhinolaryngology, Hirosaki University School of Medicine, Hirosaki, and Department of Otorhinolaryngology, Shinshu University School of Medicine, Matsumoto, Japan; Katholieke Universiteit Nijmegen, Nijmegen, The Netherlands; University of Cape Town Medical School, Department of Genetics, Cape Town, South Africa; ENT Department, Universita di Ferrara, Ferrara, Italy; Department of Audiology, Sahlgrenska University Hospital, Gotebörg, Sweden; Molecular Otolaryngology Research Laboratories, Department of Otolaryngology-Head and Neck Surgery, University of Iowa, Iowa City
| | - R. J. Smith
- Department of Genetics, Boys Town National Research Hospital, and Center for Molecular Genetics, Monroe-Meyer Institute for Genetics and Rehabilitation, University of Nebraska Medical Center, Omaha; Department of Otorhinolaryngology, Hirosaki University School of Medicine, Hirosaki, and Department of Otorhinolaryngology, Shinshu University School of Medicine, Matsumoto, Japan; Katholieke Universiteit Nijmegen, Nijmegen, The Netherlands; University of Cape Town Medical School, Department of Genetics, Cape Town, South Africa; ENT Department, Universita di Ferrara, Ferrara, Italy; Department of Audiology, Sahlgrenska University Hospital, Gotebörg, Sweden; Molecular Otolaryngology Research Laboratories, Department of Otolaryngology-Head and Neck Surgery, University of Iowa, Iowa City
| | - J. Sumegi
- Department of Genetics, Boys Town National Research Hospital, and Center for Molecular Genetics, Monroe-Meyer Institute for Genetics and Rehabilitation, University of Nebraska Medical Center, Omaha; Department of Otorhinolaryngology, Hirosaki University School of Medicine, Hirosaki, and Department of Otorhinolaryngology, Shinshu University School of Medicine, Matsumoto, Japan; Katholieke Universiteit Nijmegen, Nijmegen, The Netherlands; University of Cape Town Medical School, Department of Genetics, Cape Town, South Africa; ENT Department, Universita di Ferrara, Ferrara, Italy; Department of Audiology, Sahlgrenska University Hospital, Gotebörg, Sweden; Molecular Otolaryngology Research Laboratories, Department of Otolaryngology-Head and Neck Surgery, University of Iowa, Iowa City
| | - William J. Kimberling
- Department of Genetics, Boys Town National Research Hospital, and Center for Molecular Genetics, Monroe-Meyer Institute for Genetics and Rehabilitation, University of Nebraska Medical Center, Omaha; Department of Otorhinolaryngology, Hirosaki University School of Medicine, Hirosaki, and Department of Otorhinolaryngology, Shinshu University School of Medicine, Matsumoto, Japan; Katholieke Universiteit Nijmegen, Nijmegen, The Netherlands; University of Cape Town Medical School, Department of Genetics, Cape Town, South Africa; ENT Department, Universita di Ferrara, Ferrara, Italy; Department of Audiology, Sahlgrenska University Hospital, Gotebörg, Sweden; Molecular Otolaryngology Research Laboratories, Department of Otolaryngology-Head and Neck Surgery, University of Iowa, Iowa City
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