Sensorineural Hearing Loss Associated with Mitochondrial DNA Mutation

Abstract

A-to-G mutation at nucleotide positions 3243 and 1555 of mitochondrial DNA may cause sensorineural hearing loss. We studied such mutation in patients with bilateral sensorineural hearing loss of unknown etiology, finding 3 cases of A3243G mutation and 1 of A1555G mutation in 46 cases. It 3243 mutation is reported to be associated with diabetes mellitus and maternally inherited sensorineural hearing loss, and our study showed 3 cased of A3243G mutation in 8 cases having both maternally inherited hearing loss and diabetes mellitus. A case of A1555G mutation occurred in 1 case of maternally inherited hearing loss. Hearing loss related to A3243G mutation was characterized by late onset in adulthood and slow progression. That in A1555G mutation was characterized by comparatively rapid hearing loss.