Polymorphisms of the filaggrin gene are associated with atopic dermatitis in the Caucasian population of Central Russia

Association of the filaggrin (FLG) gene with atopic dermatitis (AD) in Caucasians from Central Russia was studied in the sample of 700 patients and 612 controls. In total ten SNPs of the gene (rs61816761, rs12130219, rs77199844, rs558269137, rs4363385, rs12144049, rs471144, rs6661961, rs10888499, rs3126085), their haplotypes and interlocus interactions were analyzed using logistic regression. The functional effects of the AD risk candidate loci and their proxies (136 SNPs) were evaluated by in silico analysis. All analyzed SNPs were associated with AD: two SNPs (rs3126085 and rs12144049) manifested the independent association, nine SNPs were associated within 30 haplotypes, and seven SNPs showed interlocus interaction effects within ten most significant epistatic models. Alleles A rs3126085 and C rs12144049 were associated with a higher risk of AD according to the allelic (ORs being 1.75, pperm = 0.002 and 1.45, pperm = 0.011 respectively), additive (ORs being 1.69, pperm = 0.004 and 1.47, pperm = 0.011 respectively) and dominant (ORs being 1.79, pperm = 0.004 and 1.63, pperm = 0.005 respectively) genetic models. Three haplotypes, GT[rs3126085-rs12144049] (OR = 0.60), GGT[rs61816761-rs3126085-rs12144049] (OR = 0.59), and AWGGT[rs12130219-rs558269137-rs61816761rs3126085-rs12144049] (OR = 0.63) demonstrated the protective effect (pperm = 0.001). The in silico analysis suggested that the AD risk variants and their proxies apparently produce various effects on 38 genes in various tissue/organs (including 20 genes in the skin). The biological process enrichment analyses suggest that the target AD candidate genes influence the formation of the cornified envelope, keratinization and cornification, and more than twenty other pathways related to skin development, programmed cell death, and regulation of water loss via skin.

Automated summary

This study investigated the association between filaggrin (FLG) gene and atopic dermatitis (AD) in Caucasians from Central Russia. The results showed that multiple SNPs of the FLG gene were associated with AD and had an impact on the disease. Additionally, protective haplotypes were identified. In silico analysis revealed that the AD risk variants and their proxies had effects on various tissue/organs, particularly the skin.