Background: Oxygen free radicals such as superoxide anion have been implicated in the pathogenesis of atherosclerosis and coronary heart disease (CHD). The nonglycosylated 22 kDa alpha-subunit of the NADH/NADPH oxidase (p22 phox) of the vasculature acts as the final electron transporter in the generation of superoxide anion. Recently, a common polymorphism (C242T) at codon 72 in the p22 phox gene has been reported to be associated with CHD risk.
Study design: We examined the role of the C242T polymorphism with the risk of CHD in a biracial sample of Asian Indians and Chinese from Singapore. The sample comprised angiographically confirmed CHD patients (126 Asian Indians and 151 Chinese) and age- and sex-matched healthy control subjects (154 Asian Indians and 167 Chinese).
Results: The frequency of the T allele was significantly higher in Asian Indian control subjects than in Chinese control subjects (0.38 vs. 0.09; P < 0. 0001). However, there was no difference in the frequency of this allele between case patients and control subjects either in Chinese (0.10 vs. 0.09) or Asian Indians (0.38 vs. 0.40). This polymorphism was also not associated with plasma lipid and apolipoprotein levels in any group.
Conclusions: The p22 phox codon 72 polymorphism is not associated with the risk of CHD in the present samples of Asian Indians and Chinese.