Deafness, Autosomal Dominant 27

Clinical Features

Peters et al. (2008) described a 3-generation family ('LMG2') segregating autosomal dominant hearing loss. All affected individuals exhibited nonsyndromic bilateral progressive sensorineural hearing loss. The reported age of onset in the 11 affected individuals ranged from 7 to 28 years. Affected individuals under the age of 40 years exhibited moderate to profound hearing loss (40- to 90-decibel loss), whereas older affected individuals had severe to profound hearing loss.

Mapping

Peters et al. (2008) performed a genomewide scan in a 3-generation family with autosomal dominant hearing loss and found significant linkage to markers in a 5.7-cM (8.85-Mb) interval on chromosome 4q12-q13.1 (maximum lod = 4.67 at theta = 0 for D4S398). The authors designated the locus DFNA27, and noted that the DFNA27 gene may be allelic to that causing recessive nonsyndromic deafness at DFNB55 (609952), a locus defined by a consanguineous Pakistani family that spans 11.3 Mb between markers D4S2978 and D4S2367 on chromosome 4q12-q13.2 and completely encompasses the DFNA27 interval defined by the LMG2 family.

Molecular Genetics

In a 3-generation family with autosomal dominant hearing loss mapping to chromosome 4q12-q13.1, Peters et al. (2008) sequenced and excluded 8 candidate genes.