Association between apoliprotein E gene polymorphism and hypercholesterolemic phenotype in maracaibo, Zulia State, Venezuela

Apoliprotein (Apo) E gene polymorphisms have been associated with high plasma lipids levels and cardiovascular disease. The aim of this study was to determine allelic and genotypic frequencies and to evaluate the associations of polymorphisms with hypercholesterolemic phenotypes in a patient population in Maracaibo, Zulia State. Two hundred and twenty-one patients with ages between 9 and 78 years old attending the Endocrine-Metabolic Center at the University of Zulia, Zulia, Venezuela, were recruited. The lipid profile was determined by enzymatic methods. ApoE polymorphisms were determined by polymerase chain reaction-restriction fragment length polymorphism. One hundred and thirty-three dyslipidemic and 88 patients with normal lipids profile were evaluated. The higher proportion of patients corresponded to hypercholesterolemia isolated (46.61%), followed by hypercholesterolemia combined with hypertriglyceridemia and low levels of high-density lipoprotein (21.8%). ApoE ε3 allele was the most frequent in the evaluated population (0.80), both in the control group (0.78) and in the dyslipidemic group (0.82), followed by the ε4 allele (0.12) for both groups and the ε2 allele with values of 0.10 and 0.06, for control and dyslipidemic group, respectively. The ε3ε3 and ε3ε4 genotypes were the most frequent in the population, with values of 62.89% and 22.17%, respectively. The genotype frequencies were 57.95% and 66.17% for ε3ε3; 23.86% and 21.05% for ε3ε4 in nondyslipidémicos and dyslipidemic patient groups, respectively. The ε4ε4 genotype was observed only in hypercholesterolemic patients. The homozygote ε2ε2 and heterozygote ε2ε3 genotypes were more frequent at the normal lipids profile group, consistent with diverse reports that indicate the association of the ε4 allele with elevated cholesterol levels and low cholesterol levels when the ε2 allele is present. ApoE polymorphism seems to be associated with variance in serum lipids levels in the population evaluated.