GWAS-identified variants to allergic disease and early environmental exposure in Chinese schoolchildren with allergic rhinitis induced by house dust mite.

Abstract

There is growing evidence that environmental exposure in early life is associated with the development of childhood allergic rhinitis. To investigate whether polymorphisms in previously published genome wide association studies (GWAS) allergic disease loci are associated with childhood house dust mite-induced allergic rhinitis (HDM-AR) and interaction effects of genetic and environmental factors on it. 156 cases diagnosed by HDM-AR and 173 controls were enrolled. Potential confounders were analyzed by using Logistic regression. Twenty-one single nucleotide polymorphisms (SNPs) of GWAS-related allergic diseases including EMSY-LRRC32, IL18R1, IL18RAP, IL13, IL4, HLA region, KIF3A were genopyped and analyzed using the improved multiplex ligation detection reaction (imLDR) technique in all the subjects. Only IL18R1_rs2287037 was associated with HDM-AR in children. After adjusting for several likely confounders, the protective TT genotype of IL18R1_rs2287037 was found in the population analyzed with the fittest recessive model. (adjusted odds ratio [aOR]: 0.44; 95% confidence interval [CI]: 0.21-0.95). The rs2287037_ TT might interact with early-life exclusive breastfeeding in the first 4 months (aOR: 0.33; 95%CI: 014-0.97) or full-term birth (aOR: 0.45; 95%CI: 0.19-0.95) exposure to decrease the risk of HDM-AR. These data suggest that IL18R1 polymorphism may play a role in controlling risk to HDM-AR and underline the importance of early environmental exposure into studies of genetic risk factors.