Filaggrin gene polymorphisms are associated with atopic dermatitis in women but not in men in the Caucasian population of Central Russia

BACKGROUND AND PURPOSE: This study aimed to analyze the gender-specific association of the filaggrin (FLG) gene polymorphisms with atopic dermatitis (AD) in Caucasians from the central region of Russia. METHODS: The study sample consisted of 906 female (including 474 patients with AD and 432 controls) and 406 male (such as 226 patients with AD and 180 controls) participants. Genotyping of ten polymorphisms of the FLG gene was done. The logistic regression was used to analyze the associations. A total of 125 SNPs (seven AD-associated SNPs and 118 proxy SNPs, r(2)≥0.8) FLG gene were used for the in silico functional annotation analysis in the females. RESULTS: Significant associations were identified between seven SNPs of the FLG gene (rs12130219, rs61816761, rs558269137, rs12144049, rs3126085, rs471144, rs6661961) and AD in females: rs12144049 was associated independent individually (for allele C OR = 1.71, 95%Сl 1.19–2.46, р(perm) = 0.004 and OR = 1.76, 95%Сl 1.18–2.63, р(perm) = 0.006 according to the additive and dominant genetic models, respectively) and seven SNPs of the FLG gene within 14 haplotypes. Haplotype GGT [rs61816761-rs3126085-rs12144049] showed the strongest association (OR = 0.55, р(perm) = 0.001). No association between the analyzed SNPs and AD was determined in the male group. The subsequent bioinformatic analysis predicted the SNPs of the FLG gene that possessed epigenetic and non-synonymous effects, were involved in the control of gene expression and alternative splicing of genes that contribute to AD pathophysiology. CONCLUSION: Polymorphisms of the FLG gene are associated with AD in females but not in males in the Caucasian population of Central Russia.