Background. Apolipoprotein E (apo E) is one of the most important constituents of plasma lipoproteins. A genetic polymorphism in the 4th exon of the apo E gene determines the existence of e2, e3 and e4 alleles in human population coding for three common isoforms of apo E: apo E2, apo E3, and apo E4. The aim of the study is to present the heterogeneity of the e4 allele frequency in the European region. Methods and Results. The mean frequency of the e4 allele is 13.6% in the whole European population (95% confidence interval: 7.2 - 20.0%; 45 evaluated studies, 19940 subjects). Frequency of the e4 is 17.7% in Northern Europe (12.0 - 23.4%; 11 studies, 4564 subjects), 15.5% in Western Europe (10.9 - 20.0%; 21 studies, 11 615 subjects), 12.8% in Central Europe (9.1 - 16.5%; 5 studies, 939 subjects), and 8.0% in Southern Europe (3.2 - 12.8%; 8 studies, 2822 subjects). The mean frequency of e4 allele established preliminary in two localities (Prague, Hradec Králové) in the Czech Republic is 15.7% (15.5 - 15.9; 2 studies, 95 subjects). Conclusions. The study confirmed an apo E - e4 frequency heterogeneity in the European population. The occurrence of e4 allele decreases from the North to the South in Europe. The highest frequency of e4 allele is in Finland (mean 22.1%), the lowest in Sardinia (5.2%).

        Key words: apolipoprotein E, genetic polymorphism, epsilon 4 allele, apo E4, population, Europe.