Is Fibrodysplasia ossificans progressiva hereditary?

Fibrodysplasia ossificans progressiva (FOP) is a genetic condition caused by a mutation in the ACVR1 gene, but it is rarely hereditary in the traditional sense. Most cases of Fibrodysplasia ossificans progressiva occur as a de novo (spontaneous) mutation, meaning the individual is the first in their family to be affected.

Is Fibrodysplasia ossificans progressiva hereditary?

While Fibrodysplasia ossificans progressiva is genetic, it is not typically passed down from parents. It follows an autosomal dominant inheritance pattern; however, because the condition significantly affects reproductive health and mobility, the vast majority of cases arise from a new mutation in the egg or sperm cell at conception. In the rare event that an individual with Fibrodysplasia ossificans progressiva decides to have children, there is a 50% chance of passing the ACVR1 mutation to each offspring.

How is the genetic cause of FOP identified?

Genetic testing for Fibrodysplasia ossificans progressiva is performed through molecular analysis of the ACVR1 gene. Because the clinical presentation can be mistaken for other conditions, such as aggressive fibromatosis or soft tissue tumors, molecular confirmation is essential. Genetic counseling is strongly recommended for families to understand the risks and the nature of the de novo mutation.

What are the testing and reproductive options?

For those navigating a diagnosis of Fibrodysplasia ossificans progressiva, clinical geneticists provide guidance on the following:

• Diagnostic Testing: Confirms the presence of the specific ACVR1 mutation.


• Prenatal Diagnosis: Available via chorionic villus sampling (CVS) or amniocentesis for parents who carry the mutation.


• Preimplantation Genetic Testing (PGT): An option for individuals with the condition who wish to undergo IVF to screen embryos before pregnancy.


• Recurrence Risk: While the risk for siblings of an affected child is generally low (less than 1%), parental germline mosaicism should be discussed with a genetic counselor.

Next steps

• Consult with a clinical geneticist to confirm your ACVR1 mutation status.


• Connect with the 49 members of the DiseaseMaps.org Fibrodysplasia ossificans progressiva community to share experiences.


• Reach out to the International FOP Association (IFOPA) for specialized resources and clinical trial updates.

Medical disclaimer: This information is for educational purposes only and does not replace professional medical advice, diagnosis, or treatment.

References

• NIH Genetic and Rare Diseases Information Center (GARD): Fibrodysplasia ossificans progressiva.


• Orphanet: Fibrodysplasia ossificans progressiva (ORPHA:337).


• Online Mendelian Inheritance in Man (OMIM): #135100.


• International FOP Association (IFOPA) clinical guidelines.