Apolipoprotein E polymorphism in the Indian and Mestizo populations of Mexico

Apolipoprotein E (APOE) genotypes were determined in 75 Mazatecan Indians a nd 83 Mexican mestizos. APOE allele and genotype frequencies in Mazatecans and mestizos were similar, with high frequencies of the APOE*3 allele (0.90 0 and 0.915, respectively) and the E3/3 genotype (0.813 and 0.831, respecti vely) and an absence in both samples of the APOE*2 allele, Our data are sim ilar to those previously described for Mexican-American and Mayan populatio ns, which show the highest frequency worldwide of the APOE*3 allele and the E3/3 genotype, Mazatecans and mestizos also show a decreased frequency of the APOE*4 allele when compared to other Amerindian groups. The absence of the APOE*2 allele has also been reported in other Amerindian groups such as Mayans and Cayapa, whereas in Caucasians the average frequency of this all ele is about 8%. Our data are in agreement with previous reports showing ab sence of the APOE*2 allele in Native American groups. These findings sugges t that the APOE*2 allele was absent in humans from northern Asia who settle d in the Arctic and populated the American continent.