Deafness can arise through defects in conduction through the outer or middle ear (conductive deafness), even though the sound-detection system is normal. A common cause is otosclerosis. See also ankylosis. Sensorineural deafness is a result of insensitivity of the inner ear, the cochlea, or dysfunction in the auditory nervous system. Cochlear defects can arise through mutations in various genes, including those for barttin, catechol-O-methyltransferase, claudin-14, cochlin, connexin, cryopyrin (Muckle–Wells syndrome), diaphanous-related formins, espin, harmonin, M-channels, otoferlin, pejvakin, radixin, V-type ATPase, whirlin, and wolframin. Deafness can also be a feature of disorders that affect multiple systems, e.g. Alport's syndrome, CHARGE syndrome, hypoparathyroidism, Jervell and Lange-Nielsen syndrome, LEOPARD syndrome, Mohr–Tranebjaerg syndrome, multiple epiphyseal dysplasia, oculodentodigital dysplasia, Pendred's syndrome, Usher's syndrome, Waardenburg's syndrome, and Woodhouse–Sakati syndrome. Some of these conditions affect structural proteins, other are involved in ion channels or synaptic structure. The mouse mutant diminuendo is interesting because it affects a miRNA. See also tubby.
Subjects: Medicine and Health.