Familial Mediterranean fever (FMF) is a genetic condition characterized by frequent, brief episodes of intense abdominal pain and fever. Additional symptoms may include chest pain due to lung cavity inflammation and skin rashes. Patients typically appear healthy between episodes. A significant concern is the abnormal accumulation of a specific protein, amyloid, in various body tissues, which can occur even without noticeable FMF attacks. The kidneys are especially vulnerable to amyloid buildup.Taking colchicine daily can prevent fever episodes in 60% of patients and significantly decrease the frequency of attacks in another 20-30%. Consistent use of colchicine is crucial, as stopping the medication can lead to an attack within days. Even if it doesn't completely stop fever episodes, colchicine effectively prevents amyloidosis.FMF affects both males and females who inherit the gene from both parents. This gene is located on the short (p) arm of chromosome 16 and is known as MEFV. It produces a mutated protein called pyrin, whose exact function remains somewhat unclear. MEFV is part of the "myelomonocytic-specific pathway" and is classified as an "interferon-gamma immediate early gene." There are at least 28 mutations in the MEFV gene that are known to cause FMF.The disorder is named for its prevalence among families of Mediterranean descent, such as Sephardic Jews, Arabs, Turks, and Armenians. Two common mutations in the MEFV gene are believed to have originated from ancestors who lived approximately 2,500 years ago in the Middle East, a phenomenon known as the founder effect.
