Familial hypercholesterolemia and the polymorphism of apolipoprotein E

Objective To elucidate the relationship between two genetic factors associatd with blood cholesterol, i.e. familial hypercholesterolemia (FH) and apolipoprotein E (ApoE).Methods The genomic DNA was extracted from 30 FH patients and 67 hyperlipoproteinemia patients. The exon 4 of ApoE fragment coding for 112 and 158 amino acid residues was amplified by PCR. After HhaI restriction enzyme digestion and electrophoresis, the short DNA fragments were detected by a silver staining method.Results The frequencies of ApoE genotypes in FH patients and hyperlipoproteinemia patients were: E3/2 3.3% and 11%;E3/3 56.7% and 63%;E4/2 10% and15.1%;E4/3 30% and 9.6%, respectively;the frequencies of ApoE alleles in them were respectively:e2 6.7% and 14.4%;e3 73.3% and 73.3%;e4 20% and 12.4%. No significant difference was found in the relationship between the distribution of these 3 genotypes and the levels of serum lipid and lipoprotein.Conclusion Apolipoprotein E4 genotype tends to increase in FH, but it has no significant effect on serum lipid profiles.