C1494T mitochondrial DNA mutation, hearing loss, and aminoglycosides antibiotics.

UNLABELLED: In view of the complex mechanism of hearing, it is not difficult to understand that hearing impairment may result from a wide variety of genetically determined anomalies and various environmental factors. Specific mutations in the mitochondrial DNA 12S rRNA gene are responsible for maternally inherited non-syndromic hearing loss, and for increased susceptibility to the ototoxicity of aminoglycoside antibiotics. AIM: To asses the presence of C1494T mutation among individuals with normal hearing and hearing impairment who used aminoglycosides and those who had not had contact with the antibiotic. MATERIAL AND METHOD: The study was composed of 20 patients with nonsyndromic sensorineural hearing loss without prior use of aminoglycosides and 40 premature and high-risk newborns who used ototoxic drugs, of whom 20 had good hearing and 20 had hearing loss. The samples were analyzed by PCR-RFLP with the restriction enzyme Hph I. STUDY DESIGN: Experimental. RESULTS: The mitochondrial 12S rRNA C1494T mutation was not detected in any of the samples analyzed. CONCLUSION: Our data suggest that the hearing loss of the individuals we analyzed was not related to the ototoxicity of mutation C1494T, showing that this mutation is not frequent in our population.