Are IVS4 SNPs of OLR1 gene associated with coronary artery disease: Is there a linkage between IVS4 SNPs?

BACKGROUND: The OLR1 gene has been identified as a candidate gene for coronary artery disease (CAD). Six single-nucleotide polymorphisms (SNPs) of the OLR1 gene located within intron 4 (IVS4-27G>C, IVS4-73C>T, IVS4-14A>G), intron 5 (IVS5-70A>G, IVS5-27G>T) and 3'UTR (188C>T) comprise a linkage disequilibrium (LD) block, which is strongly associated with the elevated risk of CAD.

OBJECTIVES: We aimed to investigate the effects of the OLR1 IVS4-14A>G and -73C>T SNPs on metabolic parameters in Turkish CAD patients, and the linkage between these 2 genetic variants.

MATERIAL AND METHODS: The present study was carried out in 97 CAD patients and 78 healthy individuals. The OLR1 IVS4 genotypings were performed by polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP) method.

RESULTS: Serum high-density lipoprotein (HDL) cholesterol levels and body mass index (BMI) were higher in control subjects with IVS4-73CC genotype than in T allele carriers (CT+TT) (respectively, p = 0.002 and p = 0.024), while BMI values were lower in patients with CC genotype (p = 0.046). Patients with IVS4-14G allele (AG+GG) had a statistically higher low-density lipoprotein (LDL) cholesterol level (p = 0.027) than patients with -14AA genotype. Also the systolic blood pressure (SBP) levels were statistically higher in IVS4- 73C allele carriers (CT+CC) than in non-carriers (TT) (p = 0.045). A strong linkage between IVS4-14A>G and -73C>T SNPs of the OLR1 gene was detected in patients (D > 0.76).

CONCLUSIONS: Our results indicated that the intron 4-14A>G and -73C>T SNPs of the OLR1 gene can be inherited together. The present data also suggests that the OLR1 gene may contribute to the development of hypercholesterolemia in patients with CAD.