The mitochondrial tRNAThr G15930A may be a novel mutation associated with hearing impairment

Abstract

Mutations in mitochondrial DNA (mtDNA) were the important causes for non-syndromic hearing loss (NSHL). However, the molecular mechanism underlying mt-tRNA mutations and NSHL remained poorly understood. In this study, we reported here the clinical, genetic, and molecular characterization of a Han Chinese family with maternally inherited NSHL. Clinical evaluation showed a variable age at onset of NSHL. Molecular analysis of the matrilineal relatives from this family showed the presence of a novel mt-tRNAThr G15930A mutation, together with a set of genetic polymorphisms belonging to East Asia haplogroup B4b1. Interestingly, the G15930A mutation, which is localized at the highly conserved nucleotide of the anticodon stem of tRNAThr, created a novel base-pairing. Bioinformatics analysis showed that the G15930A mutation altered the secondary structure of tRNAThr and may result a failure in tRNA metabolism. As a result, the G15930A mutation may cause the mitochondrial dysfunction that was responsible for NSHL. Taken together, our data indicated that the G15930A may be a novel mutation associated with NSHL. Thus, our finding provided novel insight into the pathophysiology of maternally inherited NSHL.

Keywords

• mitochondrial
• trnathr
• g15930a
• nshl