Conductive hearing loss in individuals with fibrodysplasia ossificans progressiva.

Fibrodysplasia ossificans progressiva (FOP) is a very rare genetic disorder that is characterized by progressive heterotopic ossification of soft tissues and congenital malformation of the great toes. Although previous case studies have reported hearing loss in individuals with FOP, there have been no large-scale studies regarding the nature or cause of the hearing loss. Here, we report the findings of a two-part study. In Part I, we report the findings of a postal survey regarding hearing loss that was sent to 102 individuals with FOP. In Part II, we report the findings of on-site hearing evaluations of eight individuals with FOP. The findings of both studies indicate that individuals with FOP are at risk for hearing loss and that the type of loss is predominantly conductive in nature, similar to that seen in individuals who have otosclerosis.