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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-rareHi FOP

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-image

tooltip-image Heterotopic 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.1-3

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

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Connect with a local physician familiar with FOP

Search our database to locate your colleagues with experience in the management of patients with FOP and find out how you contact them.

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†

*Based on one study that used probabilistic record-linkage of two French databases to estimate the prevalence of FOP in France as of 1 January 2012; †Based on one study that estimated the incidence of FOP in the US by compiling records of patients seen by the authors (at the University of Pennsylvania, the Mayo Clinic and the University of California 
San Fransisco) and patients known to the International Fibrodysplasia Ossificans Progressive Association. The cut-off date for inclusion in the analysis was 22 July 2020.

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 at: 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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All rights reserved. January 2024