Photos of a Fibrodysplasia Ossificans Progressiva, or FOP patient with severe bone formation. It is caused by a genetic mutation of the body’s repair mechanism that is supposed to stop skeletal growth after the body is fully formed. But instead, this protein never turns off. It is forever poised to send out signals telling the body to create more bone. The trigger for FOP’s errant bone formation is physical trauma to the body, anything from a bump, bruise or even dental work or an immunization shot. This damage should prompt the body to make repairs to itself, but FOP causes the body to make new and unneeded bone. Surgical procedures to remove this bone result in even more new growth since surgery itself causes intense physical trauma.