✓ Fibrodysplasia ossificans progressiva (FOP) is a rare, autosomal dominant disorder characterized by congenital malformation of the great toes and episodes of soft tissue swelling that lead to progressive heterotopic ossification. The genetic cause of FOP was recently discovered to be a recurrent missense activating mutation in the activin A type I receptor, a bone morphogenetic protein type I receptor in all classically affected individuals worldwide. The authors present a child with the classic features of previously undiagnosed FOP who developed a paraspinal soft-tissue mass after a lumbar puncture for a fever workup. Excision of the mass resulted in a massive inflammatory response leading to progression of heterotopic ossification. Awareness of the classic clinical features of FOP prior to the appearance of heterotopic ossification can prompt early clinical diagnosis and confirmation through genetic testing, thus avoiding interventions that lead to irreversible iatrogenic harm.
Abbreviations used in this paper: FOP = fibrodysplasia ossificans progressiva; LP = lumbar puncture; MR = magnetic resonance.
Address correspondence to: Phillip B. Storm, M.D., Division of Neurosurgery, Children's Hospital of Philadelphia, 6th Floor, Wood Building, 34th Street and Civic Center Boulevard, Philadelphia, Pennsylvania 19104. email:
ShoreEMXuMFeldmanGJFenstermacherDAChoTJChoiIH: A recurrent mutation in the BMP type I receptor ACVR1 causes inherited and sporadic fibrodysplasia ossificans progressiva. Nat Genet38:525–5272006
ShoreEM, XuM, FeldmanGJ, FenstermacherDA, ChoTJ, ChoiIH, : A recurrent mutation in the BMP type I receptor ACVR1 causes inherited and sporadic fibrodysplasia ossificans progressiva. 38:525–527, 2006)| false