Familial Mediterranean fever is an inflammatory disorder that causes recurrent fevers and painful inflammation of your abdomen, lungs and joints.Nonsense or missense mutations in the MEFV (Mediterranean fever) gene appear to cause the disease in many cases. MEFV produces a protein called pyrin (derived from the association with predominant fever) or marenostrin (derived from the phrase "our sea," because of the Mediterranean heritage of most patients).
The protein is expressed mostly in neutrophils. Its exact function is unknown, but it may function as an inhibitor of chemotactic factor (C5a) or perhaps of interleukin (IL)–8. Individuals with normal pyrin/marenostrin levels may have the ability to deactivate the target chemotactic factor when it is produced in response to an inflammatory stimulus. However, patients with FMF lack this ability, resulting in uninhibited activity of the chemotactic factor and episodes of inflammation (with accompanying fever) in the peritoneum, pleura, and joints.
Medications used to control signs and symptoms of familial Mediterranean fever include:
The frequency of FMF in any location depends on the ethnic background of the population. To survive ethnic and religious persecution, many Mediterranean families converted to other religions or intermarried members of other ethnic groups, thus carrying the MEFV gene with them. In Ashkenazi Jewish people (descended from Eastern European Jewish people and including most European and American Jewish people), the prevalence of FMF is 1 case per 73,000 population, with a MEFV gene frequency now estimated at perhaps 1 per 5, in contrast to previous estimates of 1 per 135.