Polymorphism of angiotensin-converting enzyme, angiotensinogen, and apolipoprotein E genes in Korean patients with cerebral infarction

The homozygous deletion allele of the angiotensin-converting enzyme gene (ACE/DD), homozygous threonine allele of the angiotensinogen gene (AGN/TT), and the ɛ4 allele of the apolipoprotein E gene (apoE/ɛ4) are reported to be associated with ischemic heart disease. Cerebral infarction (CI) is another atherosclerotic disease, and the effects of these polymorphisms on CI have been confusing. The frequency of the DD genotype of the ACE gene, but not the TT genotype of the AGN gene and the ɛ4 allele of ApoE, was significantly higher in subjects with than those without CI in Japan. In this study, we investigated whether ACE/DD, AGN/TT, and apoE/ɛ4 genotypes are associated with CI and whether genetic risk is enhanced by the effect of one upon another. We ascertained these genotypes in patients with CI (n=365), diagnosed by brain computed tomography. Control subjects for the infarction group were randomly selected from 319 subjects matched for age, gender, and history of hypertension with patients. The ACE/DD genotype was not associated with CI. Frequency of the AGN/TT genotype was higher in patients with CI than in controls (x²=12.287, p<0.05). The frequency of t allele was 0.88 in patients and 0.82 in controls (x ²=11.041, p<0.05; odds ratio, 1.7). Furthermore, the AGN/TT genotype increased the relative risk for CI in subjects with the ACE/DD genotype (x ²=7.8, p<0.05; odds ratio, 1.9). There was no significant association between apoE/ɛ4 and CI. These results suggest that AGN/TT predicts CI and ACE/DD enhances the risk for CI associated with AGN/TT in a Korean population.