VDR Gene Polymorphisms and Allergic Diseases: Evidence from a Meta-analysis.

Associations between vitamin D receptor ( VDR ) gene polymorphisms and allergic diseases were already reported by many publications. The aim of this meta-analysis was to clarify associations between VDR gene polymorphisms and allergic diseases by combing the results of all relevant publications. Eligible publications were searched from Pubmed, Embase, WOS and CNKI. We used Review Manager to combine the results of individual studies. Twenty-one studies were included in this study. Combined results proved that VDR rs1544410 BsmI (over-dominant comparison: p = .04, OR = 1.14, 95% CI 1.01-1.29; allele comparison: p = .03, OR = 1.11, 95% CI 1.01-1.22) and rs731236 TaqI (dominant comparison: p = .01, OR = 1.18, 95% CI 1.04-1.33) polymorphisms were both associated with allergic diseases. In subgroup analyses by type of disease, we confirmed positive results for rs1544410 BsmI polymorphism in both asthma and atopic dermatitis, and for rs731236 TaqI polymorphism in atopic dermatitis. Besides, in subgroup by ethnicity of participants, we observed significant associations with allergic diseases for rs7975232 ApaI polymorphism in Caucasians, for rs1544410 BsmI polymorphism in Asians and Caucasians, and for rs731236 TaqI polymorphism in Asians. We also investigated associations between VDR rs2228570 FokI polymorphism and allergic diseases, yet no any positive results were detected for this polymorphism. If we only focused on asthma, then positive findings were detected for rs1544410 BsmI polymorphism in Caucasians, and for rs731236 TaqI polymorphism in Asians. Collectively, this meta-analysis proved that VDR rs7975232 ApaI, rs1544410 BsmI and rs731236 TaqI gene polymorphisms may confer susceptibility to allergic diseases in certain populations.