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This website is intended for
U.S. healthcare professionals only.

Fibrodysplasia Ossificans Progressiva (FOP)

If you see lumps and
bumps like these

Go feet first

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Not actual patient; depiction of a person living with FOP.

What is FOP icon

What is FOP?

FOP is a progressive, disabling, ultra-rare Hi FOPUltra-rare
The Food and Drugs Administration defines a rare disease as any condition affecting less than 200,000 people. There is no formal definition of an ultra-rare disease in the US,6 but in the UK, the National Institute for Health and Care Excellence has defined it as a prevalence of <1 per 50,000 people.7
genetic disorder that is characterized by cumulative and irreversible heterotopic ossification (HO)tooltip-imagetooltip-imageHeterotopic ossification
Heterotopic ossification, or HO, is the presence of bone where bone should normally not exist.3
within soft and connective tissues that leads to loss of mobility and shortened life expectancy.3

Resources icon


Browse a host of downloadable resources to learn more about FOP, including guidance for emergency care and a diagnostic handbook.

FOP estimated prevalence

FOP has an estimated prevalence of

1.36 per million4

FOP prevalence in the US has been estimated at

0.88 per million5

1. Pignolo RJ et al. Orphanet J Rare Dis 2019;14:98. 2. Kaplan FS et al. J Bone 2010;92:686–691. 3. Kaplan FS et al. J Bone Joint Surg Am 1993;75:220–30. 4. Baujat G et al. Orphanet J Rare Dis 2017;12:123; 5. Pignolo R et al. Orphanet J Rare Dis 2021;16:350. 6. Rare diseases at FDA. U.S. Food & Drug Administration. Available Accessed July 2023. 7. Harari S and Humbert M. Eur Res Rev 2020;29:200195.


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Please always consult a healthcare professional if you require healthcare advice or if you have any specific concerns regarding Fibrodysplasia Ossificans Progressiva. This website has been developed by Ipsen in collaboration with those living with Fibrodysplasia Ossificans Progressiva and the healthcare professionals who care for them. The information provided here is not intended to replace professional advice.

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