Effect of polymorphisms of endothelial nitric oxide synthase on ischemic stroke: A case-control study in a Chinese population

BackgroundNitric oxide (NO) synthesized by endothelial nitric oxide synthase (eNOS) plays a key role in vascular regulation and atherosclerosis, therefore, eNOS may be a candidate gene for ischemic stroke (IS). However, it is still controversial whether eNOS polymorphisms are a risk factor for IS.MethodsThree polymorphisms of the eNOS gene (− 922A/G, − 786T/C, 894G/T) were determined by using TaqMan SNP genotyping assay in 309 Chinese patients with IS and 309 Chinese controls.ResultsThe frequency of eNOS − 922 G allele was significantly higher in the patients than the controls (12.14% vs 8.09%, P = 0.018). The distribution of eNOS genotypes differed insignificantly between the 2 groups. The frequency of the eNOS − 786 CC genotype was higher in the patients than the controls (OR = 3.819, P = 0.029). With respect to − 922A/G, the AG + GG genotype increased the risk for IS (OR = 1.523, P = 0.047). After adjustment for confounding factors, the odds ratios of − 786 CC and − 922 variant genotype (AG + GG) for IS were 4.580 and 1.656, respectively. However, haplotype analysis revealed the frequencies of Hap4 (GCG) and Hap7 (GCT) were significantly higher in the patients than the controls (P = 0.035, 0.042).ConclusionseNOS − 922A/G and − 786T/C may affect the susceptibility to IS and certain haplotypes of the eNOS gene may be associated with a higher susceptibility to IS.