DNA polymorphisms of human apolipoprotein A-IV gene: frequency and effects on lipid, lipoprotein and apolipoprotein levels in a French population

Genetic polymorphisms of apolipoprotein (apo) A-IV have been shown to influence lipoprotein metabolism in some human populations. In this study, we have evaluated the physiological effect of three apo A-IV polymorphisms (Gln_{360- < His}, Thr_{347- < Ser} and XbaI within the second intron of the apo A-IV gene), in a French population, on seven quantitative traits: total cholesterol and triglycerides, cholesterol of HDL, apo A-IV, apo B, apo A-I and glucose. The polymorphism at amino-acid 360 was determined by direct analysis of polymerase chain reaction products. The allele frequencies were 0.92 for the A-IV¹ and 0.08 for the A-IV² allele. The genetic polymorphism at codon 347 was investigated by allele-specific oligonucleotide hybridization. The allele frequencies of the two alleles, A-IV^347Thr and A-IV^347Ser, were 0.78 and 0.22, respectively. The XbaI polymorphism was investigated by polymerase chain reaction followed by XbaI restriction enzyme digestion of the amplified products. The frequencies of the two apo A-IV alleles, XbaI-1 and XbaI-2, were 0.79 and 0.21, respectively. None of the three apo A-IV polymorphisms had a significant effect on lipoprotein, apolipoprotein and glucose levels.