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

Abstract

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. A retrospective study of 12 consecutive FOP patients referred to and admitted in the rheumatology unit at an urban tertiary care academic center between 1991 and 2011. Data, such as age, gender, and past medical history, were collected from the medical history, physical examination, and skeletal survey in order to characterize the clinical presentations. All 12 children (six boys and six girls; ages 2.0-13.5 years) had congenital malformations of the great toes (microdactyly and hallux valgus deformity), in addition to heterotopic ossification presenting as multiple soft tissue tumor-like swellings. Spinal involvement, most notably in the cervical region, suggestive of an early FOP, was present in 83.3 %. Eleven patients (91.6 %) had a prior history of direct physical trauma, while 7 of 11 (63.6 %) had undergone invasive diagnostic procedures, both correlating with the exacerbations of their condition. Clinical awareness of fibrodysplasia ossificans progressiva and its early diagnostic features, particularly congenital malformations of the hallux, during a thorough neonatal examination may lead to an early diagnosis preventing the development of disabling, practically irreversible lesions of heterotopic ossification. Genetic and molecular studies can play a considerable role in the diagnosis of FOP in suspected cases. Early institution of prophylactic and precautionary measures, such as categorical avoidance of trauma and invasive procedures, can significantly reduce the debilitating acute exacerbations of the condition.