Clinical and audiological follow up of a family with the 8363G > A mutation in the mitochondrial DNA

Hearing loss is relatively common in mtDNA-related disorders. While auditory function has been assessed folly in the syndrome of mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes, few studies have investigated the degree of progressive hearing deficit in individuals bearing other mtDNA mutations. We performed a 4-year clinical and audiological follow LIP in a family carrying the 8363G > A mutation in the mitochondrial transfer ribonucleic acid lysine (tRNA(Lys)) gone who displayed a progressive neuro-muscular disease. In addition to Pore tone audiometry, we considered distortion products of otoacoustic emissions, a sensitive indicator of cochlear dysfunction, as well as brainstem auditory evoked responses. A generalized increase in the auditory threshold at follow LIP, indicating a cochlear impairment in three cases, was noted. Distortion products Of otoacoustic emissions may reveal sub-clinical cochlear dysfunction, even in oligosymptomatic patients. A complete and periodical assessment of the hearing function Should be encouraged in asymptomatic relatives of patients carrying the tRNA(Lys), 8363G > A Mutation. (C) 2009 Elsevier B.V. All rights reserved.