GENETIC AND CLINICAL-FEATURES OF SENSORINEURAL HEARING-LOSS ASSOCIATED WITH THE 1555-MITOCHONDRIAL-MUTATION

Five Japanese families showing aminoglycoside-induced hearing loss wer e genetically as well as clinically investigated. A mitochondrial muta tion at nucleotide 1555 was found in 28 out of 32 subjects, One hundre d American control subjects did not show any evidence of the mutation at nucleotide 1555, suggesting that the 1555 A-->G (A1555G) mitochondr ial mutation may be found more frequently among populations in the Asi an continent, Many subjects who harbor this mitochondrial mutation exh ibit a mild, high-frequency, progressive hearing loss even without ami noglycoside injection, The results presented here appear to support th e hypothesis that the A1555G mutation may play a more general role in causing hearing loss.