Familial Mediterranean fever is a genetic disorder associated with frequent fever attacks. The disease is classified as an auto-inflammatory disease because the immune system is activated independently of a pathogen and triggers inflammation. Overall, familial Mediterranean fever is a rare disease, but it is significantly more common in certain regions and population groups. This also gives the disease its name, as the affected regions are particularly Turkey, Armenia, Italy and the Arab Emirates. Familial Mediterranean fever is a chronic disease.
Causes
Familial Mediterranean fever is an autosomal recessive inherited disease. Every person has two variants of each gene. One from the mother and one from the father.
The gene coding for familial Mediterranean fever is not a single gene. Many different genes have already been found. However, one sick gene is not enough to cause the disease to break out, because the carriers still have a healthy gene.
However, if both parents are carriers of the mutation, statistically it happens in every fourth child that both genes are affected. In these children the disease breaks out. This is completely independent of the sex of the children, since it is an autosomal disease and both men and women have each gene duplicated.
In certain regions there are particularly large numbers of gene carriers. In Turkey, for example, every tenth person carries a mutation for familial Mediterranean fever. As a result, about one in 400 children carries familial Mediterranean fever. The mutations cause the immune system to be regularly activated and thus trigger inflammation and fever attacks. The inflammations particularly affect the peritoneum, pleura, pericardium and joints.
Diagnosis
It often takes several months to years before familial Mediterranean fever is diagnosed. Those affected often come to the clinic for acute abdominal pain and fever attacks. Once other causes of the fever have been ruled out, a screening test can be performed, in which the most common genetic mutations are examined. However, if the test result is negative, familial Mediterranean fever cannot be ruled out, as only about 80 percent of those affected react positively.
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