Evaluation of the frequency of R202Q mutation in patients with familial mediterranean fever in the middle black sea region of Turkey

Abstract

Familial Mediterranean Fever is a chromosomal inherited inflammatory disease, often accompanied by symptoms such as joint pain, abdominal pain and fever. Although Familial Mediterranean Fever is a chronic disease, it can show acute recurrent attacks. These attacks last for a short time, but their frequency is not exactly known. The Mediterranean Fever (MEFV) gene encodes a protein called pyrin that causes FMF disease. Hundreds of mutations have been identified in the MEFV gene, mostly in exon 2 and exon 10. We investigated the mutation prevalence in patients with FMF in the Central Black Sea region of Turkey. We retrospectively examined data from 617 patients tested for molecular genetics. In the study, Light Cycler (Roche) Real Time PCR system and TIB Molbiol LightSNiP reagents were used for mutation analysis. The mutations detected in the analyzed samples, in descending frequencies were 44.91% for R202Q; 22.46% for M694V; 10.82% for E148Q; and 8.24% for V726A. The frequencies of four mutations were detected in the 1-2% range. R652H and M694I mutations were not detected. The highest allele frequency was detected as 27.86% in R202Q mutation. We found the frequency of the M694V allele, which is common in patients with FMF, was 13.24% and for V726A it was 4.20%. For other mutations detected less frequently, we found allele frequencies as below 1 percent. At least one mutation was detected in most of the patients (71.89%). We identified 16 compound and 3 complex genotypes. As a result, we found a high linkage disequilibrium between the R202Q mutation discussed in our study and the M694V mutation, which is quite common in FMF patients. Comprehensive genotyping studies in larger populations are needed to clarify the genetics of the disease and to contribute to diagnostic testing.