Association between interleukin-17A polymorphism and coronary artery disease susceptibility in the Chinese Han population.

Coronary artery disease (CAD) is a major global health problem. In China, the incidence of CAD and the rate of mortality arising from it have increased every year. Interleukin-17A (IL-17A) is a proinflammatory cytokine produced by activated T cells, and it may be involved in the development of CAD. Genetic polymorphisms in functional regions of the IL17A gene have a plausible role in modulating the risk of CAD. To evaluate the role of IL17A polymorphisms as a risk factor for CAD, we performed a detailed analysis of possible functional single nucleotide polymorphisms (SNPs) in regulatory regions of IL17A. This study examined the potential association between CAD and five SNPs (rs8193037, rs8193036, rs3819024, rs2275913, and rs3748067) of the IL17A gene. The allelic or genotypic frequencies of the rs8193037 (promoter region) and rs8193036 (promoter region) polymorphisms in CAD were significantly different from those in healthy controls. The CAD subjects had a significantly lower frequency of the A allele of rs8193037 (P = 0.009, OR = 1.772, 95%CI = 1.146- 2.742) and the T allele of rs8193036 (P = 0.010, OR = 1.754, 95%CI = 1.139-2.701). Strong linkage disequilibrium was observed in one block (D' > 0.9). Significantly fewer T-G-G-A haplotypes (P = 0.045) were found in CAD subjects in block 1. These data suggest that IL17A gene polymorphisms confer susceptibility to CAD, and support the notion that dysfunction of IL-17A is involved in the pathophysiological process of CAD.