A novel locus for autosomal dominant nonsyndromic hearing loss, DFNA50, maps to chromosome 7q32 between the DFNB17 and DFNB13 deafness loci

Abstract

N Nonsyndromic sensorineural hearing impairment (NSSHI) is the most common form of genetic deafness. Approximately 20% of cases segregate as autosomal dominant (AD) traits, for which about 40 DFNA loci have been mapped and 17 genes have been identified, making ADNSSHI an extremely heterogeneous disorder. N In this study, we report the mapping of a novel autosomal dominant deafness locus on 7q32, DFNA50, by studying a large multigenerational Spanish family segregating postlingual and progressive ADNSSHI affecting all frequencies. A maximum LOD score of 10.66 at h = 0 was obtained for marker D7S530. The analysis of recombinant haplotypes located DFNA50 within a 3.8 cM region delimited by markers D7S1875 and D7S2519. N Four deafness loci (DFNB14, DFNB4, DFNB17, and DFNB13) were previously mapped to chromosome 7q, but their genetic intervals do not overlap with that of DFNA50, which is located 3.8 cM distal to DFNB17 and 13.7 cM proximal to DFNB13. N Sequencing of two candidate genes, SMOH and UBE2H, within the DFNA50 interval did not reveal the cause of deafness in this family