Allele and genotype frequencies for the locus encoding apolipoprotein E, involved in the regulation of lipid metabolism (APOE), were evaluated in 16 populations representing 12 ethnic groups (a total of 1103 subjects) from Russia and neighboring countries. In the populations examined, the frequencies of allele 4, which is the risk factor of Alzheimer's disease and coronary heart disease, varied from less than 5 to more than 20%, while the variation of the major 3 allele in these populations ranged from less than 75 to 95%. The frequencies of alleles 3 and 4 were 0.714 and 0.205 in Saami, 0.735 and 0.220 in Komi-Izhemts, 0.770 and 0.130 in Komi-Zyryans, 0.771 and 0.149 in Udmurts, 0.734 and 0.149 in Maris, 0.841 and 0.122 in Evenks, 0.788 and 0.163 in Buryats, 0.764 and 0.202 in Chukchi, 0.875 and 0.075 in Iranians, 0.956 and 0.044 in mountain-dwellers of the Pamirs, 0.771 and 0.094 in Ukrainians, and 0.795 and 0.091 in Belarussians, respectively. In Russians from different regions of the country, the frequencies of these alleles were 0.728 and 0.139 (Kostroma), 0.795 and 0.105 (Moscow), 0.857 and 0.092 (Rostov-on-Don), and 0.824 and 0.083 (Krasnodar), respectively. The latitudinal distribution of the APOE 3 and 4 allele frequencies in the populations examined was comparable to the frequency distribution pattern of these alleles in other populations of Eurasia. © 2007 Pleiades Publishing, Inc.