Association of Extracellular Superoxide Dismutase Gene with Cerebral Infarction in Women: a Haplotype-based Case-control Study

It has been reported that oxidative stress is a factor in cerebral infarction (CI). Extracellular superoxide dismutase (EC-SOD) is important in preventing oxidative stress, and the cerebral infarct size of EC-SOD knockout mice is significantly larger than that in wild-type controls. The aim of this study was to investigate the relationship between CI and the human EC-SOD gene using single-nucleotide polymorphism (SNP) in Japanese individuals. We selected five single-nucleotide polymorphisms of the human EC-SOD gene (rs13306703, rs699473, rs17881426, rs2536512 and rs1799895) and performed a case-control study using each SNP and haplotype in 175 CI patients (103 men, 72 women) and 299 controls (144 men and 155 women). Among women, there were significant differences between the CI and control group in overall distribution of alleles for rs699473 (men: OR=1.031, 95% CI: 0.705-1.506, women: OR=1.916, 95% CI: 1.196-3.071) and rs2536512 (men: OR=0.774, 95% CI: 0.523-1.146, women: OR=2.107, 95% CI: 1.227-3.462). In a haplotype-based case control on rs13306703, rs699473 and rs1799895 in women, the frequency of the C-C-C haplotype was significantly higher in the CI group than in the control group (men; 51.5% vs 51.4% p=0.9865, women; 62.5% vs 49.7% p=0.0108). Multiple logistic regression analysis also revealed a significant difference in C-C-C haplotype in women, even after adjustment for confounding factors (OR=2.205, 95% CI: 1.069-4.552 p=0.032). The C-C-C haplotypes could be genetic markers for CI, and the EC-SOD gene may be a susceptibility gene for CI in women.