Mitochondrial rRNA and tRNA and hearing function.

The human ear is a delicate sensory apparatus of hearing for normal communication, and its proper functioning is highly dependent on mitochondrial oxidative phosphorylation. The first mitochondrial point mutation for nonsyndromic and aminoglycoside-induced hearing loss was identified in 1993. Since then a number of inherited mitochondrial mutations have been implicated in hearing loss. Most of the molecular defects responsible for mitochondrial disorder-associated hearing loss are mutations in the 12S rRNA gene and tRNA genes. In this review, after a short description of normal hearing mechanisms and mitochondrial genetics, we outline the recent advances that have been made in the identification of deafness-associated mitochondrial mutations, and discuss how mitochondrial dysfunction contributes to hearing loss.