TMC1 and hearing loss disorder: In this study, we sought to (1) elucidate the prevalence of hearing loss (HL) caused by TMC1 variants in a large cohort of non-syndromic hearing loss patients, (2) analyze the rate of HL deterioration in TMC1-associated ADNSHL patients, and (3) carry out haplotype analysis of the TMC1: NM_138691:c.1627G > A:p.Asp543Asn variant identified from 11 unrelated ADNSHL families to confirm whether the mutation occurred by founder mutation or in a mutational hotspot.