Progressive Ossifying Fibrodysplasia: Symptoms, Causes, Risk Factors, Diagnosis, Treatment and Prediction

It is a condition in which the bone grows out of the skeleton.

Abnormal bone growth replaces connective tissue, including tendons and ligaments.

A genetic mutation causes progressive ossifying fibrodysplasia (FOP). The only recognized condition 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 the people with this disease also have malformed thumbs.

Excessive bone growth begins in the neck and shoulders, leading to periodic episodes of painful inflammation. A mild fever sometimes accompanies this.


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, leading to malnutrition and weight loss. Talking can also be challenging.
  • About half of people experience hearing impairment.
  • Poor blood flow can accumulate 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:

  • Language.
  • Diaphragm.
  • Extraocular muscles.
  • Cardiac muscle
  • Soft muscle


A mutation in the ACVR1 gene causes this disease. This gene is involved in the growth and development of bones. The modification 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.

Risk factor’s

Progressive ossifying fibrodysplasia is extremely rare. There are 800 confirmed cases worldwide, with 285 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 in moving.
  • 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. Specific tests and treatments for other conditions can cause outbreaks and stimulate bone growth.


No treatment 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 reduce pain and swelling during outbreaks.
  • Non-steroidal anti-inflammatory drugs between epidemics.
  • 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 more incredible bone growth.

An essential part of your treatment plan is 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, increasing 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.