ABSTRACT
Studies in molecular genetics are accumulating an impressive quantity of knowledge on the aetiopathology of hearing loss, as the mapping and cloning of genes reveal their functions in the inner ear, its structural organisation, and its homeostasis. Currently, several hundred chromosomal loci have been identified and associated with syndromal and nonsyndromal hearing impairments. This number has been estimated to represent about half of the genetic changes resulting in hearing impairments. Thus, genetic factors have to be considered in diagnostic audiology much more frequently than in the past. At present, clinical audiology has to meet two requirements. First, there is the need for deeper knowledge of the pathophysiological changes that gene mutations induce in the auditory system; second, there is a need for new audiological diagnostic tools sensitive enough to elucidate these changes. This could help to better define the phenotype and narrow, to within a reasonable range, the set of genetic investigations necessary.
