Genetic Update on Auditory Neuropathy

Auditory neuropathy (AN) is defined as a sensorineural hearing impairment (HI) characterized by preserved cochlear outer hair cell function with normal otoacoustic emissions but abnormal or absent brainstem evoked potentials. The prevalence of AN in HIs remains to be established and its pathophysiology has not been determined. Several environmental and genetic causes have been identified, but the majority of cases remain unexplained. In the last 10 years, many genes have been identified in isolated and/or syndromic HI. Some of them (OTOF, PJVK, DIAPH3, OPA1, FXN, PMP22, ERCC6, ERCC8, SLC19A2 and TIMM8A, for example) are responsible for phenotypes corresponding to the AN definition. This review will focus on isolated and syndromic forms of AN for which the causative genes have been identified.