253
|
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.
Collapse
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
| |
Collapse
|