[Audiologic evaluation in a family showing diabetes mellitus and deafness associated with a mutation in mitochondrial DNA].
An A to G transition at nucleotide 3,243 in the tRNA(Leu)(UUR) gene of mitochondrial DNA has recently been identified as a pathogenic point mutation which is associated with diabetes mellitus and sensorineural deafness in several pedigrees. We have also reported a family showing the association of deafness and diabetes mellitus as the predominant clinical features with this mutation. Audiologic data from two patients in this family are presented. Both had a bilaterally symmetrical sensorineural hearing loss at all frequencies. As is often the case with deafness associated with a mitochondrial disorder, the pure-tone threshold values were maximal at high frequencies in both patients. The audiologic work-up presented not only cochlear characteristics but also signs suggestive of retrocochlear disturbance with poor speech discrimination scores as compared to pure-tone thresholds, although auditory brain-stem responses showed neither wave delay nor prolonged interpeak latencies.
D000293:Adolescent; D001299:Audiometry; D004272:DNA, Mitochondrial / Q000235:genetics*; D003638:Deafness / Q000150:complications / Q000235:genetics* / Q000503:physiopathology; D048909:Diabetes Complications; D003920:Diabetes Mellitus / Q000235:genetics*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017237:Mitochondrial Encephalomyopathies / Q000503:physiopathology; D017354:Point Mutation
D004272:DNA, Mitochondrial