What is Familial Mediterranean Fever?
Familial Mediterranean fever (FMF) is a condition caused by harmful genetic changes (mutations) in the MEFV gene. Mutations in the MEFV gene affect the production of a protein called pyrin, which is involved in controlling inflammation within the body. Uncontrolled inflammation can lead to repeated (recurrent) episodes (attacks) of pain and fever in patients with FMF.
Symptoms during an attack can include headache, fever, and pain, which are caused by inflammation of the membranes surrounding the abdomen (peritonitis), joints (synovitis), and lungs (pleuritis), or other organs. Some individuals also develop patches of red, tender, and swollen skin (Erysipelas-like erythema). The recurrent attacks usually last for one to three days and vary in severity. Between attacks, an affected individual typically feels normal, and these symptom-free periods can last for days or even years. Factors such as infection, hormone cycles, and stress may contribute to the timing of these episodes. In most individuals, the first attack occurs before the age of 20. Children who have FMF may experience episodic fever as the only symptom.
Some individuals with FMF develop a protein buildup (amyloidosis) in various parts of the body, notably the kidney. If left untreated, this can lead to life-threatening kidney failure. Individuals who do not experience the characteristic attacks of FMF can still develop this form of kidney failure.
Untreated FMF can also result in decreased fertility.
Some individuals with two mutations in the MEFV gene may never have any signs or symptoms, while some individuals with only one mutation in the MEFV gene may develop symptoms. Consequently, in the absence of a personal and/or family history of inflammatory disease, MEFV mutation status cannot be used with certainty to predict an individual's risk for symptoms.
How common is Familial Mediterranean Fever?
FMF is most common among ethnic groups from the Mediterranean region, notably individuals of Armenian, Arab, Turkish, Iraqi Jewish, and North African Jewish ancestry, in which the prevalence is approximately 1 in 200 to 1 in 1,000 individuals. In all other populations, the prevalence of FMF is lower.
How is Familial Mediterranean Fever treated?
There is no cure for FMF, but in most patients, a daily dose of the drug colchicine is effective in preventing the disease's characteristic attacks. Colchicine also prevents the dangerous buildup of proteins in the kidneys, which could otherwise lead to kidney failure.
Treatment for episodic attacks is supportive in nature, such as when medications are used to help ease pain and inflammation. Individuals who do develop serious kidney failure may require kidney transplantation.
What is the prognosis for an individual with Familial Mediterranean Fever?
With early and regular treatment, individuals with FMF can live a normal lifespan and may even be free of symptoms. The disease has the potential to be life-threatening if the patient develops kidney failure (which may result when a person is untreated or does not respond to treatment).