Apolipoprotein E ε4 allele frequencies in Europe in relation to Alzheimer's disease

A clear north to south decline in the frequency of the epsilon 4 allele of the apolipoprotein E (apoE) gene was found in continental western Europe. Patients with Alzheimer's disease (AD) have 2-3 times the apoE epsilon 4 allele frequency compared to that of control populations, but the prevalency of AD is apparently similar in all European populations studied. As hypercholesterolaemia and coronary heart disease are more common in populations living in northern Europe it is possible that the apoE epsilon 4 allele has differing effects on morbidity and mortality, depending on age.