P065 A case of fibrodysplasia ossificans progressiva in Kenya

Abstract Background Fibrodysplasia Ossificans Progressiva (FOP) is an extremely rare and disabling disorder affecting 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. The objective of our case study is to describe a rare but interesting case of fibrodysplasia ossificans progressiva (FOP) in an African setting. Methods This was a retrospective case review Results Two-year-old boy presented with painful firm masses of bony consistency over the axilla, neck, occiput and the forehead for seven months. He developed progressive inability to lift the arms, flex his neck and had a characteristic stiff posture while walking. The masses had a waxing and waning nature lasting about 4–5 days but with no complete resolution. He was previously treated with antibiotics for lymphadenitis which was diagnosed by biopsy of the neck mass at a different health facility. On examinationhe had bony masses on the posterior aspect of the neck tender on palpation and attached to the underlying subcutaneous tissue. Similar masses were found on his anterior and posterior chest wall measuring 1 cm by 1 cm anteriorly and larger masses- measuring 5 cm by 5 cm posteriorly. He had bilateral hallux valgus and both elbows held in fixed flexion. His fingers had varying degrees of fixed flexion. The lower limbs were unaffected. Laboratory evaluation within normal ranges. extensive dystrophic soft tissue calcification around both elbows outlining the joint capsules. dystrophic soft tissue calcification in the bilateral axillae extensive “sheet like” soft tissue dystrophic calcifications overlying the posterior elements of the vertebral column separate from the vertebrae. Histology showed muscle replacement by hyaline cartilage and bone with intervening fibromyxoid stroma. Discussion & Conclusions This case is meant to raise awareness of this rare disease across Africa. The misdiagnosis of FOP approaches 90% of cases worldwide. Definitive genetic testing of FOP is now available and can now confirm a diagnosis before the appearance of heterotopic ossifications. Clinical suspicion of FOP early in life on the basis of malformed great toes can lead to early clinical diagnosis. Current management focuses on early diagnosis, avoidance of trauma and optimization of function. A short course of oral steroids is beneficial in prevention of flares.