Mitochondrial disease and ototoxicity

Como parte del programa de “screening” genetico para la perdida de la audicion; se realizo el estudio de mutaciones en los genes rRNA 12S y tRNAser (UCN), a partir del DNA mitocondrial, que estan asociadas con la perdida de audicion inducida por antibioticos aminoglucosidos (ATB-AG) y de presentacion no sindromica. Se estudiaron 40 pacientes con sorderaneurosensorial, la cual podria haber sido causada posterior al tratamiento con ATB-AG. El sujeto afectado y el control, luego del examen fisico completo y extraccion de DNA a partir de sangre periferica, se amplifico y estudio segmentos en el gen 12S rRNA y en el gen tRNAser (UCN) por PCR-RFLP. En presencia de una mutacion, se analizo el genoma mitocondrial completo en el probando y su familia por linea materna. Estos resultadosse han correlacionado con los valores de la relacion dela citocromo oxidasa / citrato sintasa, el cual indica unapobre actividad de la citocromo oxidasa. La clinica en el“pedigree” por linea materna y los estudios moleculares,bioquimicos y morfologicos, podria indicar que se tratade una presentacion sindromica de la mutacion 7444G>Aen Cordoba - Argentina.(AU) As part of the "screening" for genetic hearing loss,was performed to study mutations in 12S rRNA and tRNAser(UCN) genes from mitochondrial DNA, which are associatedwith hearing loss induced by antibiotics aminoglycosides(ATB-AG) and non-syndromic presentation. We studied40 patients with sensorineural hearing loss, which could have been caused subsequent to treatment with ATB - AG. The affected individual and control, after a completephysical examination and extraction of DNA fromperipheral blood, was amplified and studied segments inthe 12S rRNA and tRNAser (UCN) genes by PCR-RFLP. In the presence of a mutation, we analyzed the complete mitochondrial genome in the proband and his family from maternal line. These results werecorrelated with the values of the ratio of the cytochromeoxidase / citrate synthase, which indicates a poor activity of cytochrome oxidase. The clinic in the "pedigree" frommaternal line and molecular, biochemical and morphological might indicate that it is a syndromic presentation of the mutation 7444G> A in Cordoba - Argentina.(AU)