Physical mapping of the mouse tilted locus identifies an association between human deafness loci DFNA6/14 and vestibular system development

The tilted (tlt) mouse carries a recessive mutation causing vestibular dysf unction. The defect in tlt homozygous mice is limited to the utricle and sa ccule of the inner ear, which completely lack otoconia. Genetic mapping of tlt placed it in a region orthologous with human 4p16.3-p15 that contains t wo loci, DFNA6 and DFNA14, responsible for autosomal dominant, nonsyndromic hereditary hearing impairment. To identify a possible relationship between tlt in mice and DFNA6 and DFNA14 in humans, we have refined the mouse gene tic map, assembled a BAC contig spanning the tlt locus, and developed a com prehensive comparative map between mouse and human. We have determined the position of tlt relative to 17 mouse chromosome 5 genes with orthologous lo ci in the human 4p16.3-p15 region. This analysis identified an inversion be tween the mouse and human genomes that places tlt and DFNA6/14 in close pro ximity.