DETECTION OF THE LOW-DENSITY-LIPOPROTEIN RECEPTOR GENE PVUII INTRON-15 POLYMORPHISM USING THE POLYMERASE-CHAIN-REACTION - ASSOCIATION WITH PLASMA-LIPID TRAITS IN HEALTHY-MEN AND WOMEN

We have used anchored PCR to amplify and sequence 1400bp of the 15th i ntron of the Low Density Lipoprotein (LDL) receptor gene, and have det ermined oligonucleotides and conditions for the genotyping of the prev iously reported PvuII polymorphism. The cutting site (CAGCTG) is creat ed by the transition of a CpG to a TpG within the sequence CAGCCG at a position roughly 600bp 5' from the splice acceptor site of exon 16. G enotype was determined in three population-based samples of healthy in dividuals. In a group of 318 men and women from Iceland the frequencie s of the Intron-19 T (cutting) allele was 0.23 (95% CI, 0.19-0.28) and was similar in men and women. In two groups of men from England (n=38 5) and Scotland (n=320), the frequency was similar, being 0.23 (0.19-0 .27) and 0.25 (0.22-0.28) respectively. Individuals who were homozygou s for the T allele had lower levels of total-cholesterol triglycerides and apolipoprotein B, than those with other genotypes, and in the com bined group of UK men this effect reached statistical significance; co mpared to the C/C group, the T/T group had 6% lower cholesterol (p=0.0 2) and 15% lower triglycerides (p=0.03). The lowering effect associate d with the T/T genotype was greater in men who were in the lowest tert ile of body mass index (<25kg/m(2)) and for the trait of apoB levels, this genotype x obesity interaction was statistically significant (p=0 .01). We thus confirm the association between this allele and lower le vels of plasma lipid levels previously reported. The availability of a PCR-based method to detect this polymorphism will facilitate further investigation of the impact of LDL-receptor gene variation in determin ing lipid levels.