Patients and Families
What does FOP stand for and when was it first documented?
A - FOP or Fibrodysplasia ossificans progressiva (Fibro-dis-playsha os-sih-fih-cans pro-gress-eva) means "soft connective tissue that progressively turns to bone." The earliest documented cases date back to the 17th and 18th centuries.
Q - How many people have FOP?
A - It is estimated that FOP affects about 3,500 people worldwide or approximately one in two million people. Such statistics may be better grasped by the following example: if a large football stadium holds 100,000 fans, one would need to fill nearly 20 football stadiums to find one person who has FOP. At the present time, researchers are aware of approximately 800 people throughout the world who have FOP.
Q - Can the extra bone be removed?
A – No, new bone will grow back and further impair mobility. Surgical intervention often results in a worsening of the condition.
Q - How is the extra bone in FOP different from the normal bone?
A - The extra bone in FOP forms by a progressive transformation of soft tissue into cartilage and bone. This is the same process by which bone regenerates (heals) after a fracture (break) occurs and is nearly identical to the process by which bone forms normally in an embryo. The abnormality in FOP occurs not in the manner of bone formation but rather in its timing and location.
Q - What is a flare-up and is it painful?
A - A flare-up occurs when the body starts to generate new bone. No one knows what initiates this process, but once it begins, it leads to tissue swelling and much discomfort. Sometimes the individual will not feel well and may develop a low-grade fever. While there is no medication or therapy that can stop the process of bone formation once it has begun, a physician can prescribe medicine to help relieve the pain. A single flare-up may continue for as long as 6-8 weeks. Multiple flare-ups may also occur during an active period of FOP. When a flare-up is in progress, joint stiffness may occur overnight. The stiffness comes from swelling and pressure inside the muscle during the earliest stages of new bone formation. While flare-ups are usually painful, the degree of pain can vary. Most people find that the pain subsides when a flare-up is over; it appears that it is the process of extra bone formation, rather than the extra bone itself, which usually leads to pain.
Q - Will FOP get worse? Does it ever stop or go away?
A - Unfortunately, FOP does not improve over time. The "P" in FOP stands for "progressiva." That means that FOP will progress, or get worse, as a person ages. As FOP is part of a person's genetic make-up, people with FOP are born with the condition, even though the extra bone may not have appeared at birth. So people with FOP will not outgrow the condition. Nor can the extra bone that has been produced by FOP disappear. The body of a person with FOP does not make extra bone all of the time; a person with FOP may go months or years without a flare-up. Yet there is always a chance that extra bone can form, either without any warning ("spontaneous flare-up") or following trauma, such as a bump, fall, muscle overexertion, an injury, intramuscular injections, surgery, or even some viruses. It is unclear why the disease is active sometimes and quiet or dormant at other times.
Q - What parts of the body are involved in FOP? How does FOP affect mobility?
A - FOP affects the neck, spine, chest, shoulders, elbows, wrists, hips, knees, ankles, jaw, and many areas in between. The progression of ossification follows a characteristic pattern. Usually extra bone forms in the neck, spine, and shoulders before developing in the elbows, hips and knees. The muscles of the diaphragm, tongue, eyes, face, and heart are characteristically spared. The well-documented and characteristic progression of FOP, as well as the regions not affected, likely hold important clues to the cause and development of the disease.
FOP affects mobility because the body's joints, such as the knees or the elbows, connect the bones and aid in movement. In FOP, extra bone replaces the ligaments (which cover the joints), as well as muscles and tendons (which move the joints). Consequently, movement in areas affected by FOP becomes difficult or impossible.
Q - What physical variations are seen from person to person?
A - The largest variation seen is the timing and rate of extra bone formation. Another common variation includes the severity of movement restriction. For example, an elbow could be fixed in a closed position, putting the hand permanently across the chest, or the elbow may be left with some range of motion.
Q - Is there any treatment for FOP?
A - At this time, there is no treatment for FOP. For now, medication is only helpful to manage the symptoms of FOP (pain, inflammation, etc.) For more information, please read The Medical Management of Fibrodysplasia Ossificans Progressiva: Current Treatment Considerations
Q - How does FOP affect a child's school life?
A - FOP does not affect a person's intelligence or cognitive abilities. It does, however, negatively impact the child's ability to safely access the school premises, use and manipulate the school's materials, and function academically in a typical way. For a detailed discussion of the various issues that may arise in school and the ways others have dealt with them, please read FOP and School and Classroom Talk to Students.