Background and aims A retrospective evaluation of clinical findings and genetic analysis of patients with Familial Mediterranean Fever (FMF) in Umraniye region of Istanbul.

Methods 44 patients with FMF were evaluated retrospectively in the Department of Paediatrics between 2013–2014 years.

Results The mean age of 44 patients was 8.8 years. Female-male ratio was 1.2:1. The clinical characteristics of patients were recorded as fever (84%), abdominal pain (72.7%), recurrent infection story (47.7%), myalgia (43.1%), arthritis (15.9%; monoarthritis, 11.4%, polyarthritis 4.5%), pleuritis (11%), erysipelas-like erythema (7%), vasculitis (2.2%). MEFV gene analysis in patients has revealed 8 mutations. The most common mutation type was M694V (47.7%) followed by E148Q (38.6%), R202Q (15.9%), M680I (11.3%), V726A (9%), P369S (6.8%), M694I and K695 (2.2%), respectively. The M694V mutation was detected in 58% of homozygous mutations. Patients with homozygous M694V mutation have shown significantly more often joint complaints when compared to patients with other mutations. The joint complaint was usually seen in the form of monoarthritis. The clinical immigrant polyarthritis ratio was 2.2%.

Conclusions Although most previous genetic studies showed that M694V mutation was the leading locus of risk for developing amyloidosis, we couldn’t determine amyloidosis in our study. In comparation with national studies, clinical signs of pleuritis, arthritis and erysipelas-like erythema determinated at lower rates in our study. The M680I mutation, which is very rare among Jews and relatively more prevalent in Aermenians and Arabs, was the fourth most common mutation in our study, although it was the second common mutation in nationwide studies.