A gene for autosomal dominant hearing impairment (DFNA14) maps to a regionon chromosome 4p16.3 that does not overlap the DFNA6 locus

Non-syndromic hearing impairment is one of the most heterogeneous hereditar y conditions, with more than 40 reported gene localisations. We have identi fied a large Dutch family with autosomal dominant non-syndromic sensorineur al hearing impairment. In most patients, the onset of hearing impairment is in the first or second decade of life, with a slow decline in the followin g decades, which stops short of profound deafness. The hearing loss is bila teral, symmetrical, and only affects low and mid frequencies up to 2000 Hz. In view of the phenotypic similarities of this family with an American fam ily that has been linked to chromosome 4p16.3 (DFNA6), we investigated link age to the DFNA6 region. Lod score calculations confirmed linkage to this r egion with two point lod scores above 6. However, as haplotype analysis ind icated that the genetic defect in this family is located in a 5.6 cM candid ate region that does not overlap the DFNA6 region, the new locus has been n amed DFNA6.