As of importance of
interleukin-4 (IL-4) in inhibiting the production of proinflammatory
cytokines, the
IL4 gene polymorphisms were investigated in patients with
febrile seizure. This association has not been investigated yet, except 1 study which has been done in Japanese population. Eighty-two patients with
febrile seizure were enrolled in this study, compared with 139 controls. The allele and genotype frequency of 3 single-nucleotide polymorphisms of
IL4 gene were determined. Frequency of the
IL4-590/C allele in the patient group was significantly higher than in the control group (P < .0001). Frequency of the following genotypes was significantly lower in patients compared to controls:
IL-4 (-590) TC (P = .0001) and
IL-4 (-33) TC (P = .001). The most frequent
IL-4 haplotype in the patient group was TCC (P = .00) haplotype. In contrast, frequencies of GCC (P = .01), TTT (P = .009), and TTC (P = .0007) haplotypes were significantly lower in
febrile seizure patients. Certain alleles, genotypes, and haplotypes in the
IL4 gene were overrepresented in Iranian patients with
febrile seizure, which could predispose individuals to this disease, and further investigations in other ethnicities are required.