What Is Fibrodysplasia Ossificans Progressiva?

Definition: Fibrodysplasia Ossificans Progressiva (FOP) is a very rare genetic condition in which any trauma, particularly soft tissue injuries (e.g. blunt force trauma, muscle injections, blood draws), can cause the rapid formation of bone tissue in muscles, tendons, and ligaments.

Clinical Symptoms:

- Progressive stiffening of joints, starting in the neck, shoulders, and back

- Limited movement and eventual immobility

- Bony bumps over joints

- Muscle pain and swelling

- Difficulty swallowing (due to jawbone involvement)

- Respiratory problems (due to chest and rib involvement)

- Vision problems (due to involvement of eye muscle)

- Hearing loss (due to involvement of ear tissues)

- Growth abnormalities

- Facial deformity

- Limited chest expansion (can lead to breathing difficulties)

- Scoliosis (curvature of the spine)

- Progressive contracture formation due to excessive bone growth

Genetics:

- Mutation of the ACVR1 (activin A receptor, type I) gene

- Autosomal dominant trait (each child of an affected parent has a 50% chance of inheriting the FOP mutation)

- Sporadic cases (no family history) of FOP are more common (60-75% of cases)

Diagnosis:

- Based on clinical symptoms, characteristic radiological findings (CT scan, MRI), and genetic testing

Treatment:

- Currently, no cure or effective treatment to stop or reverse the ectopic bone formation.

- Management strategies focus on pain relief, physical therapy, surgery (to remove problematic bone growths and correct deformities), and genetic counseling.