ABSTRACT
In 1993, a five-generation family with hereditary hearing impairment associated with cochleosaccular degeneration was identified (Fig. 1) (1). Through linkage analysis, this family was mapped to chromosome 22q12.2-q13.3, spanning a 17-23-cM region, defining a new locus for nonsyndromic hereditary hearing impairment DFNA17 (2). Subsequently, a mutation in MYH9, responsible for the DFNA17 was identified (3). The mutation R705H, a consequence of G-A transition in the nucleotide sequence, is considered critical for the ATPase activity of the myosin motor domain. Simultaneously, mutations in MYH9 have also been identified in hereditary macrothrombocytopenia (4, 5). Herein, the DFNA17 phenotype and genotype-phenotype correlations are discussed.
