title: Mutations in the myosin VIIA gene cause non-syndromic recessive deafness.
abstract: Genetic hearing impairment affects around 1 in every 2,000 births. The bulk (approximately 70%) of genetic deafness is non-syndromic, in which hearing impairment is not associated with any other abnormalities. Over 25 loci involved in non-syndromic deafness have been mapped and mutations in connexin 26 have been identified as a cause of non-sydromic deafness. One locus for non-syndromic recessive deafness, DFNB2 (ref. 4), has been localized to the same chromosomal region, 11q14, as one of the loci, USH1B, underlying the recessive deaf-blind syndrome. Usher syndrome type 1b, which is characterized by profound congenital sensorineural deafness, constant vestibular dysfunction and prepubertal onset of retinitis pigmentosa. Recently, it has been shown that a gene encoding an unconventional myosin, myosin VIIA, underlies the mouse recessive deafness mutation, shaker-1 (ref. 5) as well as Usher syndrome type 1b. Mice with shaker-1 demonstrate typical neuroepithelial defects manifested by hearing loss and vestibular dysfunction but no retinal pathology. Differences in retinal patterns of expression may account for the variance in phenotype between shaker-1 mice and Usher type 1 syndrome. Nevertheless, the expression of MYO7A in the neuroepithelium suggests that it should be considered a candidate for non-syndromic deafness in the human population. By screening families with non-syndromic deafness from China, we have identified two families carrying MYO7A mutations.
authors.affiliation: MRC Mouse Genome Centre, Harwell, Oxfordshire, UK.
authors.forename: X Z
authors.initials: XZ
authors.lastname: Liu
authors.forename: J
authors.initials: J
authors.lastname: Walsh
authors.forename: P
authors.initials: P
authors.lastname: Mburu
authors.forename: J
authors.initials: J
authors.lastname: Kendrick-Jones
authors.forename: M J
authors.initials: MJ
authors.lastname: Cope
authors.forename: K P
authors.initials: KP
authors.lastname: Steel
authors.forename: S D
authors.initials: SD
authors.lastname: Brown
mesh_terms: D000328:Adult; D000818:Animals; D002880:Chromosomes, Human, Pair 11; D003638:Deafness / Q000235:genetics*; D004398:Dyneins; D005091:Exons; D005808:Genes, Recessive; D006579:Heterozygote; D006801:Humans; D051379:Mice; D008875:Middle Aged; D009154:Mutation; D000081412:Myosin VIIa; D009218:Myosins / Q000235:genetics*; D010375:Pedigree; D012326:RNA Splicing
chemical_list: C000631455:MYO7A protein, human; C000631456:Myo7a protein, mouse; D000081412:Myosin VIIa; D009218:Myosins; D004398:Dyneins