Background: Reproducibility of results is important for the validity of genetic association studies. Recently, 3 functional polymorphisms, G(-930)A in CYBA, T481S in CLCNKB, and E65K in KCNMB1, were reported to be associated with blood pressure (BP) status and the aim of this study was to confirm those findings using a large cohort representing the general Japanese population.
Methods and results: The study population consisted of 3,652 subjects recruited from the Suita study as representative of the general population in Japan. The genotypes of the 3 polymorphisms were determined by the TaqMan method. Logistic analysis indicated that the CYBA/G(-930)A polymorphism was associated with hypertension in male subjects. In the male population, the odds ratio of the GG genotype over GA + AA was 1.27 (95% confidence interval 1.01-1.57, p=0.034). Moreover, residuals of systolic and diastolic BP values were significantly higher in subjects with the GG genotype than in those with the GA or AA genotype (p=0.0007). However, such significant effects of the genotype on BP status were not observed in the female population. The significance of the CLCNKB/T481S and KCNMB1/E65K polymorphisms were not replicated in the present study.
Conclusion: The significance of the G(-930)A polymorphism of CYBA was confirmed in the present study with adequate statistical power, which strengthens the hypothesis that this polymorphism is important in the pathogenesis of hypertension and confers susceptibility.