Background: The Taq/B, Msp/ and I405V polymorphisms of cholesteryl ester transfer protein (CETP), an important regulatory factor of lipid metabolism, have been attracted much more attention by the researchers. In this study, we investigated the associations between these 3 polymorphisms of CETP gene and variations in plasma lipid and lipoprotein levels in patients with coronary heart disease (CHD).
Methods: Genomic DNA was extracted from leukocytes of 203 CHD patients and 100 control subjects using the salting out method. Genotyping of the CETP gene was performed using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) techniques. Statistical analysis was conducted using the SPSS 10.0 software package.
Results: The distribution of allele and genotype frequencies of the Taq/B, MspI, and I405V polymorphisms was similar in the CHD patient group and the control group. The B1B1 genotype of the Taq/B polymorphism was associated with significantly higher TC (P=0.039) and LDL-C (P=0.044) levels than the B2B2 genotype in CHD patients, and with significantly higher LDL-C (P=0.034) levels than the B2B2 genotype in controls. Homozygotes of the I405V polymorphism exhibited significantly higher HDL-C levels than VV homozygotes among control subjects (P=0.023). In male CHD patients with unambiguously assigned haplotypes, B2-M2-V/B2-M2-I patients demonstrated significantly higher HDL-C concentrations than B1-M2-V/B1-M2-I (P=0.023) and B1-M2-V/B1-M2-V patients (P=0.047).
Conclusions: Genetic variations in the CETP gene may account for a significant proportion of the differences in plasma lipid and lipoprotein concentrations among the general population. The B1B1 genotype of the Taq/B polymorphism is probably a genetic risk factor for CHD in the study population.