Hereditary sensorineural hearing loss of unknown cause involving mitochondrial DNA 1555 mutation

We report on a family with maternally inherited sensorineural hearing loss, in which no history of aminoglycoside injection and no other specific etio logy could be identified in any member. A 1555 A-to-G mutation of mitochond rial DNA was found in all members demonstrating hearing loss. The hearing i n the propositus and his sister was severely impaired at a younger age than that in the mother. This case suggests that the 1555 point mutation of mit ochondrial DNA has potential to promote inherited nonsyndromic hearing loss without any known etiology. Copyright (C) 2000 S. Karger AG, Basel.