Evaluation of 20 years experience of fibrodysplasia ossificans progressiva in Iran: lessons for early diagnosis and prevention.

Fibrodysplasia ossificans progressiva (FOP) is a rare genetic inflammatory disorder characterized by progressive heterotopic ossification presenting as recurrent soft tissue masses and swelling which may cause disabling, restricted joint mobility. Congenital malformations of the hallux are characteristic features of classic FOP, predating the appearance of disabling features. As no definite treatment is available, the early diagnosis and prevention of exacerbating factors may lead to significant benefits in terms of the life quality of patients.