Apolipoprotein E polymorphism in Brazilian dyslipidemic individuals: Ouro Preto study

ABSTRACT

The influence of apolipoprotein E alleles and genotypes on plasma lipid levels was determined in 185 individuals of mixed ethnicity living in Ouro Preto, Brazil. DNA was obtained from blood samples and the genotypes were determined by an RFLP-PCR procedure. The *3 allele was the most frequent (72 percent), followed by *4 (20 percent) and *2 (8 percent); *4 frequency was higher and *2 frequency was lower in the dyslipidemic group than in the normal control group. The *2 carriers presented lower LDL and total cholesterol levels compared to the *3 and *4 carriers. All six expected genotypes were observed in the individuals genotyped E2/2 (2.1 percent), E4/4 (2.7 percent), E2/4 (3.7 percent), E2/3 (8.0 percent), E3/3 (53.3 percent), E3/4 (29.9 percent); no difference in genotype frequencies was found between the normal and dyslipidemic groups. Compared with *2, the presence of *3 increases more than two times the risk for dyslipidemia (OR = 2.31; P = 0.025; 95 percent CI = 1.06-5.06) and the presence of *4 increases it three times (OR = 3.31; P = 0.006; 95 percent CI = 1.36-8.04). The only significant effect of genotype was an increased risk for dyslipidemia in the *4 genotype carriers (E3/4 + E4/4) compared with the *2 genotype carriers (E2/2 + E2/3) with OR = 3.69 (95 percent CI = 1.25-10.88). The present study indicates that in the Ouro Preto admixed population the presence of APOE *2 can confer a protective effect, whereas the presence of APOE *4 implies an enhanced risk for dyslipidemia.