Carrier rate in Sephardic Jews:
1 in 3 to 1 in 7 in North African Jews, Iraqi
Jews, Armenians and Turks. It is estimated to be as high as 1 in 5
for Ashkenazi Jews, in whom the disease is much milder.
Approximately 1 in 200 for Sephardic Jews
Carrier rate in the general population:
Other ethnic groups in which it occurs:
Age of onset of symptoms:
Episodes of fever, rash, difficulty breathing, arthritis and painful inflammation in the abdomen, chest or joints normally begin in childhood or early adolescence. These vary in severity and can last between 12 and 72 hours. Left untreated, amyloidosis can result in kidney failure, and fertility may be reduced. Stress and extreme physical exercise have been shown to precipitate attacks. There are no symptoms between episodes.
Lifespan is normal in individuals with the
disorder, especially with management.
What causes the features of the disease:
White blood cells require a protein called
pyrin (also known as marenostrin) to help regulate inflammation,
which in turn is a site-specific process that fights infection and
repairs tissue. When mutations on the MEFV gene reduce the amount of
pyrin manufactured, the body loses control of the inflammation
process, which is then prolonged or inappropriate to the body's
condition. Familial Mediterranean fever (FMF) is an episodic
condition which can also result in amyloidosis, or potentially
dangerous buildup of protein in organs and tissues.
Treatment or management:
While the underlying cause of the disorder
has no cure, the symptoms of inflammation can be managed with
non-steroidal anti-inflammatory drugs (NSAIDs). Renal failure can be
addressed with organ donation. A drug called colchicine, which
prevents inflammatory attacks and amyloidosis, may be prescribed as
well, though some affected individuals may not be responsive to this
Carrier testing - number of mutations screened for and detection rate in the
Sephardic Jewish population:
Genetic testing of the MEFV gene can identify
up to 80% of Iraqi Jewish carriers, 90% of Ashkenazi Jewish carriers
and 95% of North African Jewish carriers.
Other testing information:
A physician knowledgeable of the symptoms can make a clinical diagnosis of FMF, or a simple blood test can be performed to check for mutations on the MEFV gene.
Researchers are currently testing various treatments for
FMF. Goto www.clinicaltrials.gov
to learn more.
For more information:
National Organization for Rare Disorders: