Heterogeneity of the Frequency of the Apolipoprotein E - e4 Allele in theEuropean Population

Summary

Background.
Apolipoprotein E (apo E) is one of the most important constituents of plasma lipoproteins. A geneticpolymorphism in the 4th exon of the apo E gene determines the existence of e2, e3 and e4 alleles in human populationcoding for three common isoforms of apo E: apo E2, apo E3, and apo E4. The aim of the study is to present theheterogeneity 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 NorthernEurope (12.0 - 23.4%; 11 studies, 4564 subjects), 15.5% in Western Europe (10.9 - 20.0%; 21 studies, 11 615subjects), 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, HradecKrálové) 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. Theoccurrence of e4 allele decreases from the North to the South in Europe. The highest frequency of e4 allele is inFinland (mean 22.1%), the lowest in Sardinia (5.2%).

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