Four genetic variants interact to confer susceptibility to atopic dermatitis in Chinese Han population.

Atopic dermatitis is a chronic inflammatory skin disease and is affected by environmental and genetic factors. Gene-gene/environment interactions are strongly believed to contribute to the genetic risk of common diseases. A number of gene-environment interactions of atopic dermatitis were performed. However, there are few comprehensive investigations on the gene-gene (or genetic variants) interactions for atopic dermatitis. We explored the association model of 6 single nucleotide polymorphisms (SNPs) which were most significant (P < 10E-05) in our previous genome wide association study (GWAS) for atopic dermatitis, and search for the possible genetic variant interactions based on the previous GWAS data using Generalized Multifactor Dimensionality Reduction and Plink 1.07 in the combined sample of 4,636 cases and 13,559 controls. The most significant associated evidence was observed under dominant model for SNPs rs3126085, rs12085366, and rs7701890, recessive model for SNP rs17173197, and additive model for SNPs rs2393903 and rs6010620. Three significant pair-way interactions were observed, including PRKAG2 and FLG SNPs (rs17173197 × rs3126085, P combined = 1.11E-15), PRKAG2 and TMEM232-SLC25A46 SNPs (rs17173197 × rs7701890, P combined = 2.22E-15), PRKAG2 and TNFRSF6B-ZGPAT SNPs (rs17173197 × rs6010620, P combined = 6.66E-16). Besides, a three-way significant interaction among PRKAG2, TMEM232-SLC25A46 and TNFRSF6B-ZGPAT SNPs (rs17173197 × rs7701890 × rs6010620, P combined = 5.99E-15) was observed in this study. These four genetic variant interactions confer susceptibility to atopic dermatitis, and highlight the genetic variant interactions in the etiology of atopic dermatitis in Chinese Han population.