RESUMO
BACKGROUND: Familial Mediterranean fever (FMF) is an autosomal recessive autoinflammatory disorder that is characterized by recurrent episodes of fever, peritonitis, pleuritis, pericarditis, and/or arthritis. MEFV is the responsible gene for FMF, of which more than 310 mutations have been reported; M694V, M694I, V726A, E148Q, and M680I mutations are the five most frequent mutations responsible for the majority of FMF patients in the Middle East. AIM: To study the genetic background of FMF among Egyptian children to detect the most frequent MEFV mutations and to study the response of colchicine therapy with different gene mutations. METHODS: This cross-sectional study included 109 pediatric patients already diagnosed clinically with FMF, and were following-up at the Rheumatology Outpatient Clinic, Children's Hospital, Cairo University. RESULTS: Out of 109 patients, 95 had positive-MEFV mutation (87.16%), of which the most frequent mutations were E148Q (24/95 patients, 25.26%), V726A (19/95 patients, 20%), M680I (19/95 patients, 20%), M694V (17/95 patients, 17.89%), and M694I (7 patients, 7.37%). A better response to colchicine therapy was noted in E148Q mutation; on the other hand, more severe cases were reported with M694V mutations. CONCLUSION: E148Q, V726A, M680I, M694V and M694I mutations are the most frequent mutations denoting the heterogeneous mutation pattern and the milder form of the disease among Egyptian patients. M694V mutations may indicate a more severe disease score.
RESUMO
BACKGROUND: Familial Mediterranean fever (FMF) is an autosomal recessive disease characterized by self-limiting recurrent attacks of fever and serosal inflammation, leading to abdominal, thoracic or articular pain. OBJECTIVE: To detect variable clinical presentations and genotypic distribution of different groups of FMF patients and the efficacy of colchicine therapy in treatment of these groups of FMF after one year. METHODS: A cross-sectional study was conducted on 70 patients already diagnosed with FMF and following-up at the Rheumatology Clinic, Children's Hospital - Cairo University. Diagnosis of FMF was determined according to Tel Hashomer criteria for FMF. All patients were subjected to a questionnaire including detailed history with emphasis on clinical manifestations and colchicine dose to control attacks. Mutational analysis was performed for all study subjects covering 12 mutations in the MEFV gene: E148Q, P369S, F479L, M680I (G/C), M680I (G/A), I692del, M694V, M694I, K695R, V726A, A744S and R761H. Response to colchicine treatment was evaluated as complete, incomplete and unresponsive. RESULTS: Out of the 70 patients- 40 males and 30 females- fever was the most common presenting feature, followed by abdominal pain, and arthritis; documented in 95.7%, 94.3%, and 77.1% of cases respectively. Mutational analysis detected gene mutation on both alleles in 20 patients (homozygotes), on only 1 allele in 40 patients (heterozygotes), and on none of the alleles (uncharacterized cases). Mild to moderate disease severity score (according to Tel Hashomer key to severity score) was detected in a significant proportion of heterozygotes and the uncharacterized group than the homozygotes. All patients received colchicine therapy; 22.9% of them showed complete response, 74.3% showed incomplete response and 2.9% showed no response to therapy. The colchicine dose needed to control attacks was significantly lower in heterozygotes than the homozygotes(P=0.04). Also patients' response to colchicine therapy was significantly better in the heterozygous group(P=0.023). CONCLUSION: Fever, abdominal pain and arthritis are the most common presenting features for homozygous, Heterozygous and uncharacterized patients. E148Q, V726A, and M680I were the most common mutations detected in the heterozygous group. Homozygosity were found for M680I, M694V, and M694I mutations in 13 patients (65% of homozygotes). Heterozygotes presenting with severe phenotype should be further analyzed for less common second MEFV mutation using gene sequencing. The colchicine dose required to control the attacks was significantly lower and patients' response to colchicine therapy was significantly better in the heterozygous group than homozygous group.