Fibrodysplasia ossificans progressiva (FOP) is a severely disabling heritable disorder of connective tissue characterized by congenital malformations of the great toes and progressive heterotopic ossification that forms qualitatively normal bone in characteristic extraskeletal sites. The disease is fibrodysplasia ossificans progressiva (Monarch Disease Ontology term MONDO_0007606). Also known as: FOP, Stone Man syndrome, Stone man syndrome, fop, progressive myositis ossificans, progressive ossifying myositis.