Genotype-phenotype correlation in children with familial Mediterranean fever in a Turkish population

Background: The aim of the present study was not only to review clinical and demographic features of child-onset familial Mediterranean fever (FMF) patients but also to investigate whether there is a phenotype-genotype correlation in the same patient population. Methods: The medical records of 102 patients with FMF were retrospectively reviewed. Patients were classified into three groups according to mutations: group 1, Met694Val-Met694Val (homozygote); group 2, Met694Val-other; and group 3, other-other. These groups were compared with regard to gender, age of onset, age of diagnosis, time interval between disease onset and diagnosis, fever, abdominal pain, arthritis, chest pain, erysipelas-like erythema, edema, amyloidosis, number of attacks per year before and after treatment, consanguinity, severity score, response of colchicines treatment, and family history of FMF and amyloidosis. Results: The presence of M694V homozygote was found to be associated with amyloidosis. Homozygosity for M694V was found in 46 patients (45%). Conclusions: M694V homozygosity is associated with phenotype II and amyloidosis compared to other common genotypes in patients with FMF. Despite current knowledge on FMF, prospective clinical studies with large numbers of patients and different ethnic groups will help us to clarify this considerable disease.