Strong Genetic

Familial Mediterranean Fever (FMF)

Name: Familial Mediterranean Fever (FMF)
Creator: Realised
Published: 2026-03-01

GeneMEFVrsIDrs28940579, rs28940580, rs3743930, rs28940578InheritanceAutosomal recessiveCarrier frequency~1 in 5 Armenians, ~1 in 5 Sephardic Jews, ~1 in 5 Turks, ~1 in 7 ArabsSystemCarrier Screening

Summary

Familial Mediterranean Fever is an autoinflammatory condition causing recurrent episodes of fever accompanied by serositis — intense abdominal pain, chest pain, or joint pain and swelling. Episodes typically last 1 to 3 days, resolve on their own, and then recur unpredictably. The primary long-term risk is AA amyloidosis, a progressive kidney disease caused by chronic inflammation, which develops in untreated individuals over years or decades. FMF is highly treatable — colchicine prevents attacks in over 90% of patients and prevents amyloidosis almost entirely. For the minority who do not respond to colchicine, IL-1 inhibitor biologics (anakinra, canakinumab) provide effective alternative tr

Practical takeaway

This matters most when planning children and when your ancestry places your partner at elevated carrier risk. In populations of Armenian, Sephardic Jewish, Turkish, or Arab descent, carrier rates are remarkably high — roughly 1 in 5. If your partner shares one of these ancestries, carrier testing through a GP or genetic counselling service is straightforward and informative. Even if your child were to inherit FMF, the prognosis with treatment is excellent — colchicine is inexpensive, well-tolerated, and dramatically effective. A genetic counsellor can discuss the specifics of variant combinations and their implications for disease severity. Realised does not calculate reproductive risk or advise on reproductive decisions.

Evidence detail

What Carrier Status Means For You

In most autosomal recessive conditions, carriers are completely unaffected. FMF is unusual in this regard — some heterozygous carriers do experience mild inflammatory symptoms, including occasional fever episodes, abdominal pain, or joint inflammation. This pseudo-dominant pattern is well documented in the medical literature and is more common with certain variants (particularly M694V). If you experience unexplained recurrent fevers or episodic inflammatory pain, mentioning your carrier status to your doctor may be clinically useful. For family planning: if both you and your partner carry MEFV variants, each child has a 25% chance of having FMF, a 50% chance of being a carrier, and a 25% chance of inheriting neither variant.

Population Context

FMF carrier rates are among the highest of any recessive condition in Mediterranean and Middle Eastern populations. The persistence of such high carrier frequencies across multiple distinct populations has led to speculation about heterozygote advantage — carriers may have had enhanced innate immune responses that protected against historically endemic infections. Armenian, Sephardic Jewish, Turkish, and Arab populations all have carrier rates near 1 in 5, while the condition is rare in Northern European, East Asian, and Sub-Saharan African populations. The M694V variant is associated with more severe disease and higher amyloidosis risk, while E148Q is associated with milder presentations and its pathogenic significance is still debated in some clinical contexts.

Limitations

23andMe tests 7 of over 300 known MEFV variants. The tested panel covers the most common pathogenic variants in Mediterranean and Middle Eastern populations (M694V, M680I, V726A, E148Q) but may miss rarer variants. The E148Q variant's pathogenic significance remains debated — it is common in many populations and may represent a low-penetrance variant rather than a classical pathogenic mutation. Genotype-phenotype correlation in FMF is imperfect: the same variant combination can produce different severity in different individuals. A "not detected" result does not eliminate carrier risk, particularly in high-frequency populations. Comprehensive carrier screening through a clinical laboratory covers more variants and provides clinical interpretation of variant combinations.

Sources (6)

Open in the Library: search, filter, every entry →