Apolipoprotein B 3′ hypervariable repeat genotype: Association with plasma lipid concentration, coronary artery disease, and other restriction fragment polymorphisms

Apolipoprotein B gene 3′ variable number tandem repeat (VNTR) and related regions were amplified by PCR and analyzed by agarose gel electrophoresis. Eighteen VNTR alleles (VNTR25, 26, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 58, 60) and 45 genotypes were observed in 477 Taiwanese subjects. The VNTR35 allele and genotype VNTR35/35 were observed most frequently in this population. The polymorphism information content was 0.62. Some minor alleles, such as VNTR25 and 60, were found only in coronary artery disease (CAD) and stroke patients in our sampling, and no statistically significant difference was observed in VNTR allelic frequency between control and CAD or stroke patients. Significant differences in allelic distribution of some VNTR alleles were observed between our normal Taiwanese population and a Caucasian group studied by others. VNTR43-47 and AluI⁺ (coding Ala⁵⁹¹) restriction fragment length polymorphism (RFLP) as well as VNTR49-60 and EcoRI^- (coding Lys⁴¹⁵⁴) RFLP were found to be highly coinherited. No apparent association between the VNTR genotype and plasma lipid concentration was observed; however, for the same genotype, the CAD and stroke patients frequently showed higher lipoprotein(a) and lower HDL cholesterol concentrations than the control group.