FAMILIAL STREPTOMYCIN OTOTOXICITY IN A SOUTH-AFRICAN FAMILY - A MITOCHONDRIAL DISORDER

The vestibular and ototoxic effects of the aminoglycoside antibiotics (streptomycin, gentamycin, kanamycin, tobramycin, neomycin) are well k nown; streptomycin, in particular, has been found to cause irreversibl e, profound, high frequency sensorineural deafness in hypersensitive p ersons. Aminoglycoside ototoxicity occurs both sporadically and within families and has been associated with a mitochondrial DNA (mtDNA) 155 5A to G point mutation in the 12S ribosomal RNA gene. We report on the molecular analysis of a South African family with streptomycin induce d sensorineural deafness in which we have found transmission of this s ame predisposing mutation. It is now possible to identify people who a re at risk of hearing loss if treated with aminoglycosides in the futu re and to counsel them accordingly. In view of the fact that aminoglyc oside antibiotics remain in widespread use for the treatment of infect ions, in particular for tuberculosis, which is currently of epidemic p roportions in South Africa, this finding has important implications fo r the family concerned. In addition, other South African families may potentially be at risk if they carry the same mutation.