Molecular biology of otosclerosis.

Otosclerosis is a bone disease of the human otic capsule, which is among the most common causes of acquired hearing loss. The pathologic process is characterized by a wave of abnormal bone remodeling in specific sites of predilection within the endochondral layer of the temporal bone. Although the cause of otosclerosis remains uncertain, there is a clear genetic predisposition with half of all cases occurring in families with more than one affected member. There is also compelling evidence that measles virus may play a role in some cases. Ultimately, how genetic factors and viral infection result in otosclerosis must be explained by effects on the molecular factors that control bone remodeling.