Maternally transmitted non-syndromic deafness was described recently both in pedigrees with susceptibility to aminoglycoside ototoxicity and in a large Arab-Israeli pedigree. Because of the known action of aminoglycosides on bacterial ribosomes, we analysed the sequence of the mitochondrial rRNA genes of three unrelated patients with familial aminoglycoside-induced deafness. We also sequenced the complete mitochondrial genome of the Arab-Israeli pedigree. All four families shared a nucleotide 1555 A to G substitution in the 12S rRNA gene, a site implicated in aminoglycoside activity. Our study offers the first description of a mitochondrial rRNA mutation leading to disease, the first cases of non-syndromic deafness caused by a mitochondrial DNA mutation and the first molecular genetic study of antibiotic-induced ototoxicity.

Recessive loss-of-function mutations of ADA2, a growth factor that is the major extracellular adenosine deaminase, can cause polyarteritis nodosa vasculopathy with highly varied clinical expression. (Funded by the Shaare Zedek Medical Center and others.).