Mitochondrial tRNA Mutations Associated With Hearing Loss*

Abstract

Mutations in the mitochondrial tRNAs are one of the causes of sensorineural hearing loss.Some tRNA mutations such as tRNALeu(UUR) A3243G are associated with hearing impairment and other clinical symptoms,while other tRNA mutations including tRNASer(UCN) T7511C only produce the phenotype of hearing loss.These tRNA mutations are the primary factors for the development of hearing loss.On the other hand,other tRNA mutations such as tRNAThr G15927A act in synergy with the primary tRNA mutations,modulating the phenotypic manifestation.The mutations alter the secondary structures of tRNAs,impair translation and decrease the ATP production.Consequently,mitochondrial dysfunctions caused by these tRNA mutations lead to hearing loss.It this review we summarize the deafness-associated mitochondrial tRNA mutations and discuss the pathophysiology of these mitochondrial tRNA mutations.