Unravelling the mystery of Fibrodysplasia Ossificans Progressiva

* As described by Dr. Frederick Kaplan – Co-Director: Centre for Research in FOP and Related Disorders University of Pennsylvania.


What is FOP?

FOP is a catastrophic sabotage of the body’s muscular skeletal system.


Children with FOP look normal at birth except for a tell-tale malformation of the big toe. At about 2 – 5 years of age, painful swellings that look like tumors begin to seize the skeletal muscles and turn them into bone. Eventually ribbons, sheets and bone cross the joints, lock them in place and make movement completely impossible because of the armament-like exoskeleton.

Even pre-school immunizations, minor bumps, bruises and muscle fatigue can cause these to flare up. Once bone forms, it’s there permanently. The bone is normal. It just shouldn’t be there. It’s an example of too much of a good thing is very, very bad.

FOP is characterized by flare-ups which can be very painful episodes of new bone formation. They often occur very suddenly. A child will go to bed fine and then the next morning, the mother will notice a swelling on the back that’s the size of a plum or an orange. These are often mistaken for tumors and misdiagnosed. Unfortunately, children undergo biopsies that are not necessary. Not only are they not necessary but they change the trajectory of the disease because the procedures themselves are a form of trauma that leads to bone formation.

It’s a very cruel progressive disease. It steals independence from children as they are growing. Eventually all this extra bone locks up all the joints – making movement impossible.


FOP is not simply a rare problem, FOP is an ultra-rare disease – affecting

*The estimated prevalence rate of 1 in 1 million is a triangulation from published literature.
Baujat et al 2017
Connor & Evans 1982



The FOP Gene…

In 2006, we discovered the FOP gene. This was a big event.

The FOP gene is like a biological terrorist and if you want to get a terrorist, you have to know where the terrorist is. Discovering the FOP gene – that one genetic letter out of 6 million – allowed us to determine not only the town, but the street, the house and the room in which the terrorist lives.

We had identified the centre of the bulls-eye of the target for FOP. It’s not the complete puzzle, but it’s a major part of the puzzle.

Professor Fred Kaplan

Co-Director: Centre for Research in FOP and Related Disorders, University of Pennsylvania.


“I think that we are really close to having a first drug that is truly effect at inhibiting and reducing the amount of bone formation.”

Dr. Eileen Shore

Co-Director: Centre for Research in FOP and Related Disorders
University of Pennsylvania.


Four pharmaceutical companies are developing investigational drugs to treat FOP. Two of those companies are currently conducting worldwide clinical trials and a third trial is being run by Kyoto University in Japan.

Several more are poised to go on line in the next year or two. That is incredible hope.


“Time weighs heavily on our shoulders because every day is a movement lost for somebody. If I could, I would call every pharmaceutical company and say, ‘Come on, hurry up.’”

Dr. Patricia Delai

FOP Clinical Care Consultant Doctor, Brazilian FOP Association
Member of the International Clinical Care Council for the Clinical Care and Treatment of FOP.



FOP Facts

  • FOP is an ultra-rare genetic condition with only 800-900 known cases in the world
  • FOP is not contagious
  • FOP knows no ethnic, racial or gender patterns
  • FOP is misdiagnosed over 90% of the time
  • FOP is a debilitating disease of progressive immobility
  • Once bone has formed, it can’t be removed because surgery causes more bone to grow
  • Disease progression is variable and hard to predict
  • FOP does not affect intelligence
  • There are thousands of people with FOP that do not know what they have.
  • People with FOP have two malformed big toes and sometimes shortened fingers


If you have FOP, or think you know someone who has, people are ready to help, contact any of the resources below to get your questions answered.