Fibrodysplasia Ossificans Progressiva

Abstract

I n 2006, researchers at the University of Pennsylvania 1 mapped to chromosome 2q23-24, and a recurrent mutation in the activin receptor type 1 (ACVR1), a bone morphogenetic protein for fibrodysplasia ossificans progressiva (FOP), was identified. The FOP is a rare autosomal dominant disease that affects 1 in 2 million individuals. The diagnosis of FOP is made by the association of progressive ossifying soft tissue swellings and great toe malformations. In this sense, Kaplan et al. 2 described the plain film characteristic findings of FOP including ectopic ossifications within soft tissues, deformed shortened great toes, or prominent calcaneal spur. Osseous bridging might be seen, and computed tomography (CT) scan can provide important information about these. 3 The most common cause of death is cardiorespiratory failure as a result of thoracic insufficiency syndrome. 4 We present the case of a 22-year-old woman who presented to the emergency with worsening of her usual dyspnea associated to sore throat and cough. On examination, she presented limitation of the thoracic movements and musculoskeletal deformities. A chest radiograph revealed multiple heterotopic ossifications of soft tissue without pulmonary infiltrates (Fig. , A). In CT scan, osseous bridging is present (Fig. , B). In this patient, antibiotic treatment was started for respiratory tract symptoms and history of intermittent corticosteroid therapy for FOP. As is demonstrated in this case, radiographic findings are important as a detection method for this disease. There is no effective treatment, although bisphosphonates or corticosteroids could improve symptoms. 5 Currently, there is an increasing consensus about the necessity for further treatment research.