It is a condition in which the bone grows out of the skeleton.
Abnormal bone growth replaces connective tissue, including tendons and ligaments.
Progressive ossifying fibrodysplasia (FOP) is caused by a genetic mutation. It is the only recognized condition that causes one organ system to metamorphose into another.
There is no cure for this chronic and progressive disorder. The goal of treatment is to reduce symptoms.
Progressive ossifying fibrodysplasia becomes apparent early in childhood. Babies are usually born with short, malformed large fingers. Problems in bones and joints make it difficult for babies to learn to crawl.
Approximately half of people with this disease also have malformed thumbs.
Excessive bone growth tends to begin in the neck and shoulders, leading to periodic episodes of painful inflammation. This is sometimes accompanied by a mild fever.
The disease progresses at a different rate for each person. Eventually, it affects the trunk, back, hips and extremities. As the disease progresses, the following symptoms may appear:
- The movement can be severely restricted as the bone grows in joints.
- The spine can be deformed or fused.
- Limited mobility can cause balance and coordination problems that can cause injuries due to falls.
- Bone growth in the chest can restrict breathing, which increases the risk of respiratory infection.
- Limited movement of the jaw can make it difficult to eat, which can lead to malnutrition and weight loss. Talking can also be difficult.
- About half of people experience hearing impairment.
- Poor blood flow can lead to the accumulation of blood in the arms or legs, causing visible swelling.
- A person with FOP can finally be completely immobilized.
Progressive ossifying fibrodysplasia does not cause additional bone growth to:
- Extraocular muscles.
- Cardiac muscle
- Soft muscle
This disease is caused by a mutation in the ACVR1 gene. This gene is involved in the growth and development of bones. The mutation allows them to grow without control.
The gene can be inherited from one of the parents, but in most cases of FOP, it is a new mutation in a person with no family history of the disease.
A father with FOP has a 50% chance of inheriting it from his son.
Progressive ossifying fibrodysplasia is extremely rare. There are 800 confirmed cases worldwide, with 285 of them in the United States.
Gender, ethnicity and race play no role. Unless you have a father with FOP, there is no way to assess your risk of developing the disease.
Because it is so rare, most doctors have never seen a case of progressive ossifying fibrodysplasia.
The diagnosis depends on the clinical history and the clinical examination. Symptoms of FOP include:
- Malformations of the big toe.
- Spontaneous outbreaks of inflammation or swelling of soft tissues.
- Increased outbreaks after injury, viral illness or immunizations.
- Difficulty to move.
- Frequent injuries due to the fall.
Excess bone formation can be seen in imaging tests such as X-rays, but they are not necessary for diagnosis. The diagnosis can be confirmed with genetic tests.
The misdiagnosis rate could be as high as 80%. The most common misdiagnosis is cancer, aggressive juvenile fibromatosis and fibrous dysplasia .
At first, the symptom that can distinguish FOP from these other conditions is a deformed big toe.
It is vital to get the correct diagnosis as soon as possible. This is because certain tests and treatments for other conditions can cause outbreaks and stimulate bone growth.
There is no treatment that can slow or stop the progression of the disease. But the treatment of specific symptoms can improve the quality of life. Some of them are:
- Corticosteroids to reduce pain and swelling during outbreaks.
- Non-steroidal anti-inflammatory drugs between outbreaks.
- Assistive devices, such as orthotics or special shoes to help walk.
- Occupational therapy
There is nothing that can make the new bones disappear. The surgery would result in greater bone growth.
An important part of your treatment plan has to do with what to avoid. A biopsy, for example, can cause rapid bone growth in the area.
Intramuscular injections, like most immunizations, can also cause problems. The dental work must be done with great care, avoiding injections and stretching the jaw.
Closed trauma or injury due to a fall can cause an attack. Any physical activity that increases these risks should be avoided.
FOP can be dangerous during pregnancy, which can increase the chances of breakouts and complications for both the mother and the baby.
Progressive ossifying fibrodysplasia is chronic and there is no cure. The treatment can help relieve symptoms and improve the quality of life.
The speed of progression is different for everyone and is difficult to predict. Some people spend months or even years without an outbreak.
The disease can become severely disabling. Most people with FOP will need a wheelchair when they reach 20 years old. The average life expectancy for people with FOP is 40 years.