title: Mutation analysis of the MYO7A and CDH23 genes in Japanese patients with Usher syndrome type 1.
abstract: Usher syndrome (USH) is an autosomal recessive disorder characterized by retinitis pigmentosa and hearing loss. USH type 1 (USH1), the second common type of USH, is frequently caused by MYO7A and CDH23 mutations, accounting for 70-80% of the cases among various ethnicities, including Caucasians, Africans and Asians. However, there have been no reports of mutation analysis for any responsible genes for USH1 in Japanese patients. This study describes the first mutation analysis of MYO7A and CDH23 in Japanese USH1 patients. Five mutations (three in MYO7A and two in CDH23) were identified in four of five unrelated patients. Of these mutations, two were novel. One of them, p.Tyr1942SerfsX23 in CDH23, was a large deletion causing the loss of 3 exons. This is the first large deletion to be found in CDH23. The incidence of the MYO7A and CDH23 mutations in the study population was 80%, which is consistent with previous findings. Therefore, mutation screening for these genes is expected to be a highly sensitive method for diagnosing USH1 among the Japanese.
authors.affiliation: Department of Otolaryngology, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nakanishi
authors.forename: Masafumi
authors.initials: M
authors.lastname: Ohtsubo
authors.forename: Satoshi
authors.initials: S
authors.lastname: Iwasaki
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Hotta
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Takizawa
authors.forename: Katsuhiro
authors.initials: K
authors.lastname: Hosono
authors.forename: Kunihiro
authors.initials: K
authors.lastname: Mizuta
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Mineta
authors.forename: Shinsei
authors.initials: S
authors.lastname: Minoshima
mesh_terms: D000293:Adolescent; D000328:Adult; D015703:Antigens, CD / Q000235:genetics*; D044466:Asian People; D001483:Base Sequence; D015820:Cadherins / Q000235:genetics*; D004252:DNA Mutational Analysis; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D009154:Mutation; D000081412:Myosin VIIa; D009218:Myosins / Q000235:genetics*; D010375:Pedigree; D052245:Usher Syndromes / Q000235:genetics*
chemical_list: D015703:Antigens, CD; C050361:CDH2 protein, human; D015820:Cadherins; C000631455:MYO7A protein, human; D000081412:Myosin VIIa; D009218:Myosins