Associations between common polymorphisms of adenosine triphosphate-binding cassette transporter A1 and coronary artery disease in a Tunisian population

Abstract

Background: The adenosine triphosphate-binding cassette transporter A1 (ABCA1) protein plays an important role in the first step of the reverse cholesterol transport system.

Aims: We studied the association of four polymorphisms in the ABCA1 gene (G1051A, G2706A, G2868A and -565C/T) with lipid profile and coronary artery disease.

Methods: Overall, 316 Tunisian patients underwent coronary angiography. Genotyping was performed using polymerase chain reaction-restriction fragment length polymorphism analysis. Lipid and apolipoprotein concentrations were measured.

Results: Only carriers of the G2706A allele were associated with a decreased risk of significant stenosis (odds ratio [OR] 0.66, 95% confidence interval [CI] 0.22-0.92, p = 0.029), without pronounced effects on high-density lipoprotein (HDL) cholesterol. This protective effect was significant in smokers and diabetes. Carriers of the G1051A allele were associated only with increased concentrations of HDL cholesterol (p = 0.032). G2868A and -565C/T did not show any association with lipids or risk of significant stenosis. When ABCA1 polymorphisms were combined in haplotypes possessing G1051A, G2706A, G2868A and -565C/T, (AAGC) seemed to be most protective against significant stenosis (OR 0.5, 95% CI 0.29-0.96, p = 0.048) whereas (GGAT) was probably the most atherogenic (OR 1.26, 95% CI 1.03-1.56, p = 0.025).

Conclusion: Only the G2706A allele seems to be associated with a reduced risk of significant stenosis without important modification of HDL-cholesterol concentration, and appears to be more protective for smokers and diabetic patients. We found that (AAGC) seems to be a protective haplotype whereas (GGAT) has an atherogenic effect in a Tunisian population.