Familial Mediterranean fever is an inherited inflammatory disorder that causes repeated episodes of fever, inflammation, and pain.
Familial Mediterranean fever (FMF) is an inherited inflammatory disorder that causes repeated episodes of fever, inflammation, and pain. The episodes develop over two to four hours and may last from several hours to several days. The periods of illness usually resolve without treatment but may damage body organs over time.
FMF occurs among people who live in areas around the Mediterranean Sea. Among Ashkenazi Jewish people, who make up a large portion of the Eastern European and American Jewish population, the FMF incidence * is 1 case per 73,000 people. Sephardic Jewish people, who are descended from Jewish populations in Spain, have a rate of 1 FMF case per 250 to 1,000 people. Some studies have shown that Arabic populations have a rate of 1 case per 2,600 people for FMF, and Turkish populations have a rate of 1 case per 1,000. Studies done on Armenian populations have shown a rate of 1 case per 500 people, although some studies have shown even higher rates for Armenians. FMF occurs more often in adult men than women and is usually seen in individuals younger than 40 years of age.
FMF symptoms include fever, which may range from 100° F to 104° F. If an episode is a mild one, the fever may be the only symptom. Most people with FMF experience episodes of abdominal pain and inflammation, which may be misinterpreted as appendicitis * . Consequently, people with FMF sometimes have procedures they do not really need, such as appendectomies * .
FMF on occasion causes inflammation of the tissue surrounding the lungs and heart. Inflammation of the joints is more common and usually involves the wrists, knees, and ankles. Joint symptoms may resemble those of more common medical problems such as gout * . FMF sufferers may experience skin rashes, especially on the lower extremities. Muscle pain may be confused with other muscle disorders. Male FMF sufferers may have painful inflammation of the scrotum, whereas females may experience pelvic inflammation. One-third of females with FMF are infertile, and FMF causes a higher rate of miscarriage * .
FMF sufferers sometimes develop amyloidosis * , where a protein called amyloid is deposited in body tissues, which can damage both the tissues and the kidneys that filter excess proteins from the blood. Kidney failure can occur in some patients who are not treated with medicine.
FMF is a difficult disease to live with due to its recurrent, painful, and disruptive nature. Patients who are not receiving colchicine therapy may develop kidney failure and die before the age of 50 years. If amyloidosis is a complication, the risk for renal failure is greater, and death by the age of 50 years is more likely. Daily therapy with colchicine greatly improves the chance of survival. Individuals with FMF on colchicine may have a normal lifespan if therapy is initiated before the development of excessive protein for the kidneys to filter and before kidney damage occurs.
See also Genetic Diseases: Overview
Gattorno, Marco, ed. Familial Mediterranean Fever. New York: Springer, 2015.
Sart, Ismail, Merih Birlik, and Timuçin Kaşifoğlu. “Familial Mediterranean Fever: An Updated Review.” European Journal of Rheumatology 1 (2014): 21–33. Available online at http://www.eurjrheumatol.org/sayilar/194/buyuk/21-33.pdf (accessed December 5, 2015).
National Human Genome Research Institute. “Learning About Familial Mediterranean Fever.” National Institutes of Health. https://www.genome.gov/12510679 (accessed December 5, 2015).
Center for Jewish Genetics. Ben Gurion Way, 30 South Wells St., Chicago, IL 60606. Telephone: 312-357-4718. Website: https://www.jewishgenetics.org (accessed December 5, 2015).
National Organization for Rare Disorders. 55 Kenosia Ave., PO Box 1968, Danbury, CT, 06813-1968. Toll-free: 800-9996673. Website: http://www.rarediseases.org (accessed December 5, 2015).
* genes (JEENS) are chemical structures composed of deoxyribonucleic acid (DNA) that help determine a person's body structure and physical characteristics. Inherited from a person's parents, genes are contained in the chromosomes found in the body's cells.
* recessive describes a gene that is not dominant, one that requires a second identical recessive gene in order for the trait to show in the individual. When a recessive gene is paired with a dominant one, the individual is said to be a carrier of the trait.
* incidence means rate of occurrence.
* appendicitis (ah-pen-dih-SY-tis) is an inflammation of the appendix, the narrow, finger-shaped organ that branches off the part of the large intestine in the lower right side of the abdomen.
* appendectomy a surgical procedure in which the appendix is removed.
* gout occurs when deposits of uric acid in the joints cause inflammation and pain.
* miscarriage (MIS-kare-ij) is the end of a pregnancy through the death of the embryo or fetus before birth.
* amyloidosis is a condition in which excessive amounts of a protein known as amyloid are created by the body and deposited in tissues causing damage.