Endothelial nitric oxide synthase gene polymorphisms and the risk of silent brain infarction.
Silent brain infarction (SBI), a unique cerebrovascular disorder, is frequently detected on magnetic resonance imaging (MRI) of apparently healthy elderly persons, and it is known to increase the risk of stroke and other related diseases. Although detailed mechanisms of SBI pathogenesis have yet to be determined, recent studies suggest that SBI is significantly influenced by genetic factors. In this study, we investigated polymorphisms in the endothelial nitric oxide synthase (eNOS) gene (i.e., -786T>C, 4a4b and 894G>T) as possible risk factors for SBI. We enrolled 269 patients with SBI and 234 control subjects and examined their fasting plasma homocysteine and folate levels, and analyzed for eNOS polymorphisms and haplotypes. The prevalence of SBI was shown to be significantly higher in patients with the eNOS 894GT genotype (OR, 2.00; 95% CI, 1.30-3.08) and 894GT+TT genotype (OR, 2.05; 95% CI, 1.34-3.16), compared with the 894GG genotype. However, in the case of -786T>C and 4a4b polymorphisms, no significant difference was observed between SBI patients and normal subjects. Interestingly, we found that the prevalence of SBI can increase twice as high when either -786T>C or 4a4b polymorphism was combined with 894G>T polymorphism, -786TC+CC/894GT+TT (OR, 3.83; 95% CI, 1.24-11.80) and 4a4b+4a4a/894GT+TT (OR, 4.08; 95% CI, 1.34-12.40), respectively. According to haplotype analysis, we found that three haplotypes (-786T-4b-894G, -786T-4b-894T and -786C-4a-894T) were shown to be significantly different between SBI patients and control subjects. These results indicate that eNOS polymorphisms and haplotypes serve as risk factors for SBI, and three different polymorphic loci in the eNOS gene play interactively, thereby leading to synergistic effects for the generation of SBI.
Song
Jihwan
J
CHA Stem Cell Institute, School of Medicine, CHA University, Seoul 135-081, Korea.
Kim
Ok Joon
OJ
Kim
Hyun Sook
HS
Bae
Su Jin
SJ
Hong
Sun Pyo
SP
Oh
Doyeun
D
Kim
Nam Keun
NK
D000368:Aged; D020520:Brain Infarction / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D052250:Nitric Oxide Synthase Type III / Q000235:genetics*; D011110:Polymorphism, Genetic; D012307:Risk Factors
D052250:Nitric Oxide Synthase Type III