FOP is frequently misdiagnosed, learn about the signs and symptoms.
Find the most up-to-date and reliable information and resources on FOP.
Fibrodysplasia Ossificans Progressiva or FOP is an ultra-rare genetic disorder that causes bone to form where it should not –outside of the skeleton and in the soft and connective tissues such as in the muscles, tendons and ligaments.1,2
FOP is ultra-rare – only around one or two people per million have the condition.2,3
FOP is caused by having a faulty copy of a gene that is involved in the normal formation of bone.4 Researchers discovered the gene responsible for extra bone formation in FOP in 2006.4
Getting a diagnosis of FOP is important as it can make a big difference in how you, or your loved one’s, health is managed.2 Knowing it is FOP means that interventions and treatments that might make FOP worse can be avoided as much as possible and mean you get the appropriate care. 3
The hallmark first sign of FOP is having shortened and turned-in great toes at birth.