[Frontiers in Bioscience 17, 1251-1265, January 1, 2012]
Genetics of isolated auditory neuropathies
Francisco J. del Castillo1, 2, Ignacio del Castillo1, 2
1Unidad de Genetica Molecular, Hospital Universitario Ramon y Cajal, IRYCIS, Madrid, Spain, 2Centro de Investigacion Biomedica en Red de Enfermedades Raras, CIBERER, Madrid, Spain
TABLE OF CONTENTS
Auditory neuropathies are disorders combining absent or abnormal auditory brainstem responses with preserved otoacoustic emissions and/or cochlear microphonics. These features indicate a normal function of cochlear outer hair cells. Thus, the primary lesion might be located in the inner hair cells, in the auditory nerve or in the intervening synapse. Auditory neuropathy is observed in up to 10% of deaf infants and children, either as part of some systemic neurodegenerative diseases or as an isolated entity. Research on the genetic causes of isolated auditory neuropathies has been remarkably successful in the last few years. Here we review the current knowledge on the structure, expression and function of the genes and proteins so far known to be involved in these disorders, as well as the clinical features that are associated with mutations in the different genes. This knowledge is permitting to classify isolated auditory neuropathies into etiologically homogeneous types, so providing clues for the better diagnosis, management and therapy of the affected subjects.