Objective: Familial Mediterranean Fever (FMF) is the most common hereditary autoinflammatory disease characterized by recurrent, febrile episodes accompanied by peritonitis, pleuritis, and arthritis. The present study aims to evaluate the distribution of MEFV gene mutations in a large patient group from a single center and compares with other studies from different regions of Turkey.

Materials and Methods: In this study, demographic and clinical informations, MEFV mutation reports, and molecular testing methods of 1113 patients admitted to pediatric genetic and medical genetic outpatient clinics of a city-state hospital with the suspicion of FMF were investigated retrospectively.

Results: 854 patients (76.7%) had at least one mutation in MEFV, whereas 259 patients (23.3%) had no mutation. Among 854 patients, 394 (46.1%) were heterozygous, 63 (7.4%) were homozygous, 240 (28.1%) were compound heterozygous and 157 (18.4%) had complex genotype. 31 different mutations and total 1507 mutations were detected. The most common five mutations were R202Q, M694V, E148Q, M608I, and P369S. 777 patients (91%) underwent MEFV sequencing and 77 patients (9%) were analyzed with strip assay technique. The most common mutation in the patients underwent strips assay was M694V (45.9%), whereas in the exon 2,3,5,10 of MEFV sequenced patients R202Q (38.3%) was detected as the most common mutation.

Conclusion: In conclusion, our study revealed different results from the previous studies from Turkey. We had a high mutation detection rate and P369S was the one of the commonest mutation in our study. According to the method used to detect MEFV variants, the mutation frequencies may vary in between the studies.