Two novel missense mutations in the TECTA gene in Korean families with autosomal dominant nonsyndromic hearing loss.

The TECTA gene, which encodes alpha-tectorin, is known as a causative gene for DFNA8/DFNA12, and DFNB21 hearing loss in humans. In the present study, mutation analysis of the TECTA gene was performed in 62 Korean patients with hereditary hearing loss. Two novel nucleotide substitutions, p.V317E and p.T1866M, were identified for the first time in the Korean population. These mutations result in the substitution of amino acids in the zonadhesin (ZA) and the zona pellucida (ZP) domains, and show a genotype-phenotype correlation, which is a characteristic of TECTA-related mutations in autosomal dominant nonsyndromic hearing loss. Both mutations are located in highly conserved regions of alpha-tectorin and were not found in 120 unrelated control subjects with normal hearing. Based on this evidence, it is likely that both mutations are the pathogenic ones causing the hearing loss. This study provides useful information for the functional study of hereditary hearing loss caused by tectorial membrane defects.