Objective: To investigate the possible association between the glutamate-cysteine ligase catalytic subunit gene (GCLC) C-129T and modifier subunit gene (GCLM) G-23T polymorphisms with coronary heart disease (CHD) in Chinese population.
Methods: GCLC C-129T and GCLM G-23T genotypes were determined in 212 CHD patients and 218 healthy individuals using a PCR-based restriction fragment length polymorphism (RFLP) method. Odds ratio (OR) for CHD and 95% confidence interval (CI) from unconditional logistic regression models were used to evaluate relative risks.
Results: The T allele of the GCLC C-129T polymorphism was more frequently found in CHD cases than in controls (P < 0.01) and individuals with GCLC-129T allele had a significantly higher risk for CHD (OR = 2.38, 95% CI: 1.25 - 4.54) as compared to individuals with the -129C allele. When compared with CC homozygote, CT heterozygote had a 2.14-fold higher risk for CHD (95% CI: 1.08 - 4.24, P < 0.05) and carriers of the-129T allele (CT or TT genotype) also had a similarly 2.28-fold higher risk for CHD (95% CI: 1.16 - 4.49, P < 0.05). In contrast, the frequency of T allele of the GCLM G-23T polymorphism was lower in CHD patients than that of controls (0.174 vs. 0.264) and individuals with the GCLM-23T allele had a significantly lower risk for CHD (OR = 0.59, 95% CI: 0.42 - 0.82, P < 0.01) as compared to the -23G allele. When compared with GG homozygote, the OR of CHD for GT heterozygote was 0.71 (95% CI: 0.47 - 1.08, P > 0.05), for TT homozygote was 0.18 (95% CI: 0.06 - 0.55, P < 0.01), and for carriers of the -23T allele (GT or TT genotype) was 0.61 (95% CI: 0.42 - 0.92, P < 0.05).
Conclusion: The GCLC C-129T polymorphism may be one of the genetic risk factor while the GCLM G-23T polymorphism may be one of the genetic protective factors for CHD in this Chinese population.