The PCSK9 gene E670G polymorphism affects low-density lipoprotein cholesterol levels but is not a risk factor for coronary artery disease in ethnic Chinese in Taiwan

Abstract

An E670G polymorphism of the exon 12 of the proprotein convertase subtilisin/kexin type 9 (PCSK9) gene was recently found to be associated with increased plasma low-density lipoprotein cholesterol (LDL-C) levels and severity of coronary atherosclerosis. This case-control study tested for a possible link between this PCSK9 polymorphism and the risk of coronary artery disease (CAD) in an ethnic Chinese population in Taiwan. The subjects included 202 CAD patients and 614 unrelated controls. Genotypes were determined via polymerase chain reaction, restriction mapping with MboII, and gel electrophoresis. Contradictory to the results of a previous report, a significantly lower level of LDL-C was noted in 670G carriers than in non-carriers (2.78+/-0.82 mmol/L vs. 3.02+/-0.85 mmol/L; p=0.029) among controls, after adjusting for age, gender, smoking, hypertension, diabetes mellitus, body mass index, and use of lipid-lowering agents. The 670G carrier was identified less frequently in patients with CAD than in controls (9.9% vs. 11.9%), but the difference was not significant in a multivariable logistic regression analysis (odds ratio=0.73; 95% CI=0.24-2.22; p=0.575). The G allele also occurred at similar frequencies in the two groups (5.0% vs. 6.0%; p=0.421). These results indicate that the E670G polymorphism of the PCSK9 gene modulates plasma LDL-C levels, but that it is not a risk variant for CAD in ethnic Chinese in Taiwan.