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