Association of ABCA1 Haplotypes with Coronary Artery Disease

Background: Adenosine triphosphate (ATP)-binding-cassette-transporter-A1 (ABCA1) transports cholesterol from cells into apolipoprotein A1 to form high-density lipoprotein (HDI) cholesterol. Methods: We investigated the frequencies of ABCA1 functional variants in 273 patients with coronary artery disease (CAD) and 261 age-matched, healthy blood donors in southwest Iran. Sequence-specific primer polymerase-chain reaction (SSP-PCR) and polymerase chain reaction-restriction fragment-length polymorphism (PCR-RFLP) were used for genotyping. Results: Frequencies of the rs2422493-TT genotype and T-allele, rs1800976-GG genotype, and G-allele in the promoter and rs2230806-GG genotype and G allele in the exon of the ABCA1 gene were higher in the patients. Abnormal left ventricular size and left-artery disease correlated with rs2422493-T and rs1800976-G alleles, respectively. Wall-motion abnormalities correlated with the rs1883025-G allele and rs2230806-A allele. Regarding the rs2422493/rs1800976/rs2230806/ rs1883025 haplotype, T-G-G-A and T-G-A-A were more frequent in case individuals, whereas C-C-G-G was more frequent in control individuals. Conclusions: The rs2422493-T allele and the rs1800976-G allele increase the risk of disease, as single polymorphisms and in the haplotype. The effect of the rs1883025-G allele is prominent in the haplotype, rather than individually. Considering that G allele of rs2230806 in the third place is present in both susceptible and protective haplotypes, the susceptibility haplotype can be defined as T-G-X-A.