A rare novel mutation in TECTA causes autosomal dominant nonsyndromic hearing loss in a Mongolian family

Background: The genetic basis of autosomal dominant nonsyndromic hearing loss is complex. Genetic factors are responsible for approximately 50% of cases with congenital hearing loss. However, no previous studies have documented the clinical phenotype and genetic basis of autosomal dominant nonsyndromic hearing loss in Mongolians. Methods: In this study, we performed exon capture sequencing of a Mongolian family with hereditary hearing loss and identified a novel mutation in TECTA gene, which encodes alpha - tectorin, a major component of the inner ear extracellular matrix that contacts the specialized sensory hair cells. Results: The novel G -> T missense mutation at nucleotide 6016 results in a substitution of amino acid aspartate at 2006 with tyrosine (Asp2006Tyr) in a highly conserved zona pellucida (ZP) domain of alpha tectorin. The mutation is not found in control subjects from the same family with normal hearing and a genotype-phenotype correlation is observed. Conclusion: A novel missense mutation c.6016 G > T ( p.Asp2006Tyr) of TECTA gene is a characteristic TECTA-related mutation which causes autosomal dominant nonsyndromic hearing loss. Our result indicated that mutation in TECTA gene is responsible for the hearing loss in this Mongolian family.