Familial Mediterranean fever: an animated, cited guide
This page needs JavaScript for its animations. The outline and key answers are below, and every claim in the full version carries a numbered citation.
Not medical advice. FMF Companion is an educational synthesis of published literature. It does not replace a clinician.
What is in it
- What FMF is Who gets it, the numbers, and what an attack looks like.
- The gene and inheritance MEFV, pyrin, the common variants and an animated Punnett square.
- Pyrin, animated How pyrin guards RhoA, and what FMF variants change.
- An attack, hour by hour 72 hours of fever, pain, CRP and SAA, site by site.
- Colchicine inside the cell From the pill to the neutrophil to the microtubule.
- Colchicine over months Why the benefit builds slowly, and what it prevents.
- Dosing, safety and interactions What the guidelines and the label publish.
- AA amyloidosis Serum amyloid A to fibril to kidney, over years.
- Diagnosis and criteria Tel Hashomer, Livneh and the Eurofever/PRINTO calculator.
- The differential TRAPS, MKD, CAPS, PFAPA, Behçet and the surgical abdomen.
- The treatment ladder Colchicine first, then IL-1 blockade.
- Living with FMF Pregnancy, surgery, school, triggers and monitoring.
- Toward a cure What a cure would need, and the evidence for each route.
- History and people 1908 to the discovery that pyrin senses RhoA.
- Flashcards, quiz and glossary Revision for students.
- Sources Every reference behind the app.
Common questions
What is familial Mediterranean fever?
Familial Mediterranean fever is an inherited autoinflammatory disease. It causes recurrent, self-limited attacks of fever with inflammation of a lining membrane, most often the peritoneum, so attacks usually bring severe abdominal pain. Attacks typically last 12 to 72 hours and stop on their own.
Which gene causes familial Mediterranean fever?
MEFV, on the short arm of chromosome 16 at band 16p13.3. It encodes pyrin, also called marenostrin. Most disease-associated variants sit in exon 10, which encodes the B30.2 domain, and the commonest are M694V, M680I, M694I and V726A.
How long does an FMF attack last?
Usually 12 to 72 hours, then it resolves without antibiotics. The Livneh criteria define a typical attack as recurrent, febrile at 38 degrees Celsius or above, and lasting 12 hours to 3 days. Joint attacks can take longer to settle.
Why does colchicine take months to work?
Colchicine is daily prevention, not a treatment for an attack already under way. It builds up inside white blood cells over days, attacks were already weeks apart so fewer of them only becomes visible over months, doses are adjusted in steps, and its largest benefit, preventing AA amyloidosis, accrues over years.
What is the most serious complication of FMF?
AA amyloidosis. Persistently raised serum amyloid A protein forms fibrils that deposit in organs, above all the kidney, where the first sign is protein in the urine, progressing to nephrotic syndrome and kidney failure. Taken regularly, colchicine prevents it.
Who gets familial Mediterranean fever?
It is most common in people of eastern Mediterranean origin: Sephardic and Mizrahi Jews, Armenians, Turks and Arabs, though it is reported worldwide. In endemic countries prevalence is roughly 1 in 500 to 1 in 1,000, and 80 to 90 percent of patients have their first attack before the age of 20.
Is familial Mediterranean fever inherited?
Classically yes, in an autosomal recessive pattern, so two variant copies are usually needed and each child of two carriers has a one in four chance. There are exceptions: some variants act dominantly, and a substantial minority of patients with typical disease carry only one identifiable variant.