A Case of Fibrodysplasia Ossificans Progressiva in Kenya

Abstract

Background: Fibrodysplasia Ossificans Progressiva (FOP) is an extremely rare and disabling disorder that affects 1 in 2 million individuals worldwide. It is caused by mutations in bone morphogenetic protein which leads to extra-skeletal ossification of soft tissues in a characteristic cranio-caudal pattern. Hallux valgus, episodic flares and progressive functional disability are characteristic features. The cause of death is often cardio-respiratory failure following thoracic insufficiency. Methods: This was a retrospective case review. Results: A two year 5-month-old boy who was otherwise normal from birth presented with a history of painful firm masses over the axilla, back, neck, elbows and occiput associated with hallux valgus and progressive inability to move both upper limbs and the neck. Radiographic features revealed pathognomonic ossification of surrounding connective tissue and histology confirmed muscle replacement by hyaline cartilage and bone. An impression of FOP was made and taper therapy with oral prednisone initiated for management of flares. Conclusions: FOP is a rare and often underdiagnosed condition. Due to the rarity of this condition, the medical fraternity’s awareness of FOP is limited and hence low diagnosis rates might reflect this lack of knowledge. This case is meant to raise awareness of this rare disease in Kenya.