General (What is Fibrodysplasia Ossificans Progressiva?)

Fibrodysplasia Ossificans Progressiva A.K.A FOP is the genetic disorder in which connective tissue (tendons and ligaments) and muscles are gradually turned to bone. This process is called Ossificaton, when new bones are formed outside of the skeleton. Extra skeletal bone formation causes decreasing ability to move when the joints become effective. Over time people with FOP start to experience malnutrition because they cannot fully open their mouths to eat food. People affected with FOP will start to have breathing problems, because extra bone is constricting their rib cage. This dissorder is so rare that only one in two million people or 2,500 world wide are affected with FOP.


Pictured below are two (a. and b. are the same case/skeleton but with different views) cases of FOP showing the excess bone compared to the one above which is a normal Skeleton.



When you are born with Fibrodysplasia Ossificans Progressiva or FOP, there is nothing noticeable that is wrong with you except that your big toe has malformations. When you are in the ages of 10 to 20 (the first two decades of your life) painful fibrous nodules form over the neck back and shoulders. The Nodules form in to bone as child matures (heterotopic ossification). Next FOP progresses along the limbs and torso of the person. These lesions over time replace the body's muscles with standard looking bone. Attempted removal of the extra bones leads to replacement bones that are harder and stronger formation. FOP cases may vary, sometimes muscle may progress into bone more rapidly, sometimes less rapidly.


People who have FOP can live a some what long life into their 50's, 60's, and sometimes even their 70's. FOP affects most parts of your body including the neck, spine, chest, elbows, wrists, shoulders, hips, knees, ankles, the jaw, and other areas in between. Ossification follows a patern, extra bone forms in the spine, neck, and shoulders before forming in the arms hips, and knees. Although there is a pattern where the ossificatin will moove to the rate at which it will progress is spuratic. When an area is affected by FOP movement in the areas becomes difficult or immpossible. A flare-up occurs when the body starts to develop new bone. No one knows what triggers its proccess, but once it starts, tissue starts to swell, and causes great pain. Sometimes the effects of a flare-up is not feeling well, or a low-grade fever. There is no medication to stop the flare-ups, only to ease the pain caused by them. Flare-ups may continue for as long as 6-8 weeks. Sometimes there are overlapping flare-ups, in which pain does not go away easily.


FOP is inherited in an autosomal dominant pattern. An autosomal dominant pattern is when one copy of the alter gene in each cell is able to cause FOP. When one parent carries the mutated gene there is a 50-50 chance the dissorder will be carried on into the child. In most cases of FOP it is a result from mutations of the gene. This occurs in people who have no history of FOP in their family. In a few cases, the person who has been affected has inherited the mutation from one affected parent. Researchers believe that a gene mutation on chromosome 4 is responsible for this genetic disorder.


The two diagrams (above and below)
show the chance
of inheriting the dissorder
through genetics(autosomal dominant).
The father in both cases carries
the heterozygus mutated gene.


Treatment/Medical Advances-

The treatment for FOP has not been developed yet. Surgery is not an option because if you remove excess bone, harder bone will reform. There is a lot of reaserch being conducted to develop a new drug that may help to control excess bone growth. Pain medication is avalible to relive symptoms and inflamation. Since each case is different and unique, the disease progression is generally unpredictable.

Discussion Questions-

-Where does the calcification of muscles, tendons, and ligaments start, and how does it progress?

-What is the most common sign of having FOP at birth?

-What is the result of trying to remove excess bone that has been formed?

"Internatonal Fibrodysplasia Ossificans Progressiva Association"( IFOPA Website)
Date assesed May, 10. Date Edited March 30, 2007
"Genetics Home Referance" (Fibrodysplasia Ossificans Progressiva)
Date assesed May 10, 2007. Date Edited May 11, 2007.
"What is FOP" (Fibrodysplasia Ossificans Progressiva. A guide book for families)
Date assesed May 14, 2007. Date edited March 30, 2007
"Case 02" (Fibrodysplasia Ossificans Progressiva)
Date assesed May 14, 2007. Date edited Febuary 11, 2007
"Treatment for FOP" (UCSF Childrens Hospital-Fibrodysplasia Ossificans Progressiva)
Date assesed May 15, 2007. Date Edited May 8, 2007
"Fibrodysplasia Ossificans Progressiva"(USCF Childrens hospital-Fibrodysplasia Ossificans Progressiva)
Date assesed May 15,2007. Date Edited May 8, 2007

By Megan and Alexander.