Stone Within: Understanding Fibrodysplasia Ossificans Progressiva

Labiba Khandaker

What is FOP? 

Fibrodysplasia Ossificans Progressiva (Stone Man Syndrome) 

FOP is an extremely rare genetic disorder in which muscles, tendons, ligaments, and other connective tissues are gradually replaced by bone through a process called heterotopic ossification (bone growing where it should not). Over time, this extra bone can lock joints in place, creating what is often described as a "second skeleton." (2) 

Does injury make it worse? 

Yes. Even relatively minor trauma—such as: 

● Falls 

● Bruises

● Intramuscular injections 

● Surgery 

● Dental procedures 

● Viral illnesses (in some cases)(2) 

can trigger painful flare-ups that are followed by new bone formation. Because of this, doctors try to avoid unnecessary invasive procedures in people with FOP. 

What causes it? 

FOP is caused by mutations in the ACVR1 gene. This mutation causes the body's bone-growth signaling to stay active when it should not, leading to bone forming in soft tissues. Most cases are due to a new (spontaneous) mutation rather than being inherited. (2) 

How rare is it? 

It is one of the rarest genetic disorders: 

● Approximately 1 in 1–2 million people are affected worldwide. ● Only several hundred to around a thousand diagnosed cases are known globally. (2,3) 

Is there a cure? 

There is no cure at present. Treatment focuses on: 

● Managing pain and inflammation during flare-ups 

● Preventing injuries that can trigger new bone growth 

● Preserving mobility as much as possible(3,4) 

Researchers continue to study new treatments, and a medication called palovarotene has been approved in some countries for certain patients to help reduce new bone formation. 

Works Cited (MLA 9) 

1. Orinjames.com, 2026, www.orinjames.com/FOP%20webpage%20%281%29.html. 2. “Fibrodysplasia Ossificans Progressiva.” MedlinePlus Genetics, U.S. National Library of Medicine, https://medlineplus.gov/genetics/condition/fibrodysplasia-ossificans-progressiva/. Accessed 30 June 2026.

3. National Center for Biotechnology Information. “Fibrodysplasia Ossificans Progressiva.” Genes and Disease, U.S. National Library of Medicine, 

https://www.ncbi.nlm.nih.gov/books/NBK22182/. Accessed 30 June 2026. 

4. Agrawal, Udit, and Vivek Tiwari. “Fibrodysplasia Ossificans Progressiva.” StatPearls, National Center for Biotechnology Information, 3 Aug. 2023, 

https://www.ncbi.nlm.nih.gov/books/NBK576373/. Accessed 30 June 2026.

Assessed and Endorsed by the MedReport Medical Review Board