Coexisting Diseases in Patients with Familial Mediterranean Fever.

Background and Aims: Familial Mediterranean fever (FMF) is a prototype of autoinflammatory disease and mainly associated with MEFV gene mutations. This single-center study as an experience represents FMF-coexisting disease in the FMF registration database.

Methods: Four hundred patients who had FMF based on clinical criteria (Tel-Hashomer) and/or MEFV mutations enrolled the study. Twelve most common MEFV mutations (P369S, F479L, M680I (G/C), M680I (G/A), I692del, M694V, M694I, K695R, V726A, A744S, R761H, E148Q) were analyzed if needed by the reverse hybridization assay. Any co-existed disease had been confirmed by a related subspecialist. All data were analyzed by a simple analytical method.

Results: Fifty-seven (14%) patients had associated disease, 32 patients were male and 24 patients were under 10 years old. They included 92 MEFV variant alleles and only in five patients there were not any mutations. The most common variant alleles were M694V (36%), E148Q (22%), V726A (17%), M680I (1%) and M694I (0.07%) respectively. Rheumatologic disorders were the most common coexisting disease, then followed by gastrointestinal and neurological disorders. Some rare diseases such as TTP, growth hormone deficiency, multiple sclerosis, idiopathic ascites, Leiden factor V deficiency and Felty syndrome have been detected. Homozygote mutations of ( M694V-M694V ) were associated with idiopathic ascites, orchitis and pericarditis.

Conclusion: Coexisting disease in patients with FMF is presented with positive MEFV gene mutations particularly with these five common variant alleles: M694V, E148Q, V726A, M680I , and M694I . The commonly associated diseases are rheumatologic, gastrointestinal and CNS disorders.