Demographic, clinic, and genetic characteristics in 149 children diagnosed with familial mediterranean fever

Abstract

Familial Mediterranean fever (FMF) is a hereditary disease characterized by recurrent attacks of fever, peritonitis, pleuritis and/or synovitis. In this study, we retrospectively evaluated demographic, clinical findings, and genetic features in 149 children (63 male/86 female) with FMF. The mean age of the patients at the time of diagnosis was 6.44 ± 3.21 years. A positive family history for FMF was present in 26%, and 8% of the patients had consanguinity between the parents. The frequency of family history of FMF was found to be higher in patients diagnosed under 10 years of age (p=0.038). Frequencies of the most frequent symptoms observed in cases during episodes were abdominal pain (95%), fever (68%), and arthralgia/arthritis (23%). Genetic analysis revealed that 16% of the patients had homozygous mutations, 32% had heterozygous mutations, and 38% had compound heterozygous mutations, while no mutations were detected in 21 (14%). There were mutant genes in 218 alleles, the most frequently observed were R202Q (48%), M694V (24%), and E148Q (17%). Patients with non-R202Q compound heterozygous mutation had higher frequency of high fever, CRP (C-reactive protein) levels, and fibrinogen levels during the episodes (p=0.006, p=0.001, and p=0.042, respectively). Thus, our study showed that R202Q mutation appeared to have no significant disease-causing and clinical effects, while mutations at exon 10 were associated with increased severity of symptoms as well as elevated levels of acute phase reactants. Further studies with larger FMF populations may shed more light on the role of these mutations in the pathogenesis of FMF.