Is Familial Mediterranean Fever hereditary?

Familial Mediterranean Fever is a hereditary autoinflammatory disorder caused by mutations in the MEFV gene, which follows an autosomal recessive inheritance pattern. Because it is inherited, the condition is passed from parents to children through genetic mutations rather than being acquired, and it typically requires two copies of the mutated gene to manifest symptoms.

Is Familial Mediterranean Fever hereditary or genetic?

Familial Mediterranean Fever is both genetic and hereditary. It is "genetic" because it is caused by specific mutations in the MEFV gene located on the short arm of chromosome 16. It is "hereditary" because these mutations are passed down through generations in families. While most cases follow a recessive pattern, some individuals with only one copy of the mutation may still experience mild or atypical symptoms, leading some researchers to debate the strictness of its classification; however, the clinical consensus remains that Familial Mediterranean Fever is primarily an autosomal recessive condition.

How is Familial Mediterranean Fever inherited?

The inheritance pattern for Familial Mediterranean Fever is autosomal recessive. This means that for a child to be affected, they must inherit one mutated copy of the MEFV gene from each parent. Parents of an affected child are typically "obligate carriers," meaning they each carry one mutated gene but do not usually show symptoms of the disease themselves. When both parents are carriers, the risks for each pregnancy are as follows:

• 25% chance that the child will have Familial Mediterranean Fever (inheriting two mutated copies).


• 50% chance that the child will be an asymptomatic carrier (inheriting one mutated copy).


• 25% chance that the child will not have the mutation at all.

Are de novo mutations common in Familial Mediterranean Fever?

De novo (spontaneous) mutations that arise for the first time in an individual are extremely rare in Familial Mediterranean Fever. The vast majority of cases occur because the mutations are inherited from parents who are carriers. Because Familial Mediterranean Fever is most prevalent in populations of Mediterranean, Middle Eastern, and North African descent, the carrier frequency in these specific ethnic groups is high, which often leads to familial clustering of the disease.

How does genetic testing and counseling work?

Genetic testing for Familial Mediterranean Fever involves sequencing the MEFV gene to identify pathogenic variants. This testing is highly recommended for confirming a clinical diagnosis, especially in patients presenting with periodic fevers and serositis. For families planning pregnancies, genetic counseling is a vital step. A genetic counselor can help determine the carrier status of partners, explain the risks of transmission, and discuss reproductive options such as prenatal diagnosis or preimplantation genetic testing (PGT) for those who wish to avoid passing the condition to their children. At DiseaseMaps.org, 264 people with Familial Mediterranean Fever have joined our community, many of whom have navigated these complex genetic discussions and can offer peer support.

Next steps

• Consult with a medical geneticist to discuss your specific family history and potential testing options.


• Request a referral to a rheumatologist who specializes in autoinflammatory diseases to manage potential symptoms.


• Connect with the 264 members on DiseaseMaps.org to share experiences and find resources for managing Familial Mediterranean Fever.


• Review your family tree with a counselor to identify relatives who may also be carriers or affected.

Medical disclaimer: This content is for informational purposes only and does not constitute professional medical advice, diagnosis, or treatment; always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.

References

• NIH Genetic and Rare Diseases Information Center (GARD): Familial Mediterranean Fever


• Orphanet: Familial Mediterranean Fever (ORPHA325)


• OMIM (Online Mendelian Inheritance in Man): MEFV Gene Entry (#249100)


• The FMF Foundation: Educational resources for patients and families