Association of 4b/a and T786C polymorphisms of endothelial nitric oxide synthase gene and carotid atherosclerosis

Objective:To investigate the association of endothelial nitric oxide synthase(eNOS) gene 4b/a and T786C polymorphisms with carotid atherosclerosis(CAS) in elderly Han population. Method:Five hundred andtwenty-one eldly Han patients undergone B-mode ultrasonography to carotid artery were enrolled in the study,among which 266 patients were CAS group,255 patients were control group.The eNOS gene 4b/a and T786C polymorphisms ware analyzed by PCR and PCR-RFLP,respectively.The plasma lipid levels and other risk factors were also determined in both groups. Result:The two polymorphisms were in linkage disequilibrium(LD).For both polymorphisms the genotypic frequencies and the allele frequency did not differ significantly between the CAD patients and controls(all P0.05).Before or after the adjustment of common risk factors such as age and gender,the association between either polymorphism and CAS failed to achieve statistical significance(all P0.05).The haplotype analysis revealed that the haplotype 4a-T was significantly associated with CAS with the adjustment for the common CAS risk factors(OR=2.86,95%CI:1.11-7.40,P=0.030). Conclusion:These results suggest that either of the 4b/a and T786C polymorphisms of the eNOS gene is associated with CAS in the studied Han population,but the constructed haplotype 4a-T may be an independent genetic marker of CAS.