Familial Mediterranean Fever: Clinical and Genetic Characteristics among Lebanese Pediatric Population

Objective: The aim of our study was to evaluate the clinical features, to define the frequency ofmutation type, to assess genotype-phenotype correlation and the response to colchicine in childhood-onset Familial Mediterranean fever (FMF) in Lebanon. Methods: The characteristics of 550children, presenting with FMF symptoms between January 2003 and January 2013 and having apositive Mediterranean fever gene (MEFV gene) mutation, were prospectively investigated. Theclinical and genetic characteristics as well as the response to colchicine and its side effects werestudied in 321 FMF children. The mutations were correlated with clinical presentation and diseaseseverity. Results: Out of the 321 patients (183 males and 138 females), abdominal pain was themost common presenting feature documented in 84.7%. Mutational analysis detected simple heterozygotes,compound heterozygotes and homozygotes in 56.4%, 30.9% and 11.2% patients respectively.The most frequent mutation was M694V (37.2%), followed by E148Q mutation (27.4%).71% patients received colchicine therapy; only 33.3% of them showed complete response. Genotype-phenotype correlation showed that M694V followed by E148Q was associated with moderateto severe disease form (71.6% and 62.7% respectively, P = 0.005). There was no association betweenmutation type and colchicine response. Conclusion: The most important features were thepredominance of the M694V and E148Q. The M694V subgroup, followed by E148Q subgroup had ahigh disease severity score. Our data indicate an enhanced expression of the disease with E148Qmutation.