Variations in APOE genotype distribution in children from areas with different adult cardiovascular disease mortality in Spain.
We investigate whether a varying distribution of the APOE genotype could help explain regional differences in ischemic heart disease (IHD) mortality in Spain. APOE genotypes were examined by PCR in 1,274 randomly selected healthy children from four Spanish regions with different adult IHD mortality rates (northwest and central Spain with low rates and southeast and southern Spain with high rates). In the population as a whole the prevalence of the higher risk APOE*3/*4 genotype is 16.8% and the prevalence of the APOE*4 allele is 10.1%. In northwest Spain the frequencies of the APOE*3/*4 genotype (12.9%) and of the APOE*4 allele (8.3%) are smaller than in the other regions. The southeast region shows statistically higher frequencies of the APOE*3/*4 genotype (22.5%) and of the APOE*4 allele (13.2%) than in the other regions or in the group as a whole. We can conclude that Spain is not homogeneous in terms of APOE genotype distribution. Although the prevalence of the APOE*4 allele is generally low, there are areas with higher prevalence of the APOE*4 allele and a higher incidence of adult IHD mortality. This allows us to conclude that in Spain this genetic determinant can be associated with IHD mortality in relatively isolated populations.