The common TMC1 mutation c.100C>T (p.Arg34X) is not a significant cause of deafness in British Asians.

TMC1, a second-tier deafness gene below GJB2, is an appreciable cause of recessive nonsyndromic hearing loss (DFNB7/11) in North Africa, the Middle East, and parts of South Asia. Additionally, a single founder mutation, c.100C>T (p.Arg34X), dominates the TMC1 mutation spectrum. We investigated the frequency of TMC1 c.100C>T in a large set of British Asians with hearing loss, collectively a group with high prevalence of genetic deafness and limited routine clinical testing options beyond GJB2, on a candidate basis. An estimate of 0.21% (95% confidence interval, 0.04%-1.18%) was gained, indicating no significant enrichment in our set. Identification of the common non-GJB2 deafness genes and mutations in British Asian communities would require data from autozygosity mapping and/or massively parallel sequencing of gene panels.