The ε4-Allel occurs in Alzheimer patients approximately 3 times as often as in the normal population (36.7% vs. 13.7 %), whereas the ε2 allele occurs more seldom than in the normal population (3.9% vs. 8.4%). Correspondingly, carriers of an APOE-ε4 allele have a higher risk of developing Alzheimer’s disease, while the ε2 allele is linked to a lower risk.
In families where late-onset sporadic Alzheimer’s disease has occurred, the risk of developing the disease and the average start of the disease depend strongly on the ε4 gene dose. 20% and 84 years for non-ε4-carriers, 47 % and 76 years for heterozygous and 91% and 68 years for homozygous carriers of the ε4 allele.
Alongside its diagnostic significance, the determination of the APOE alleles is gaining more and more pharmacogenetic importance in the development of new Alzheimer medications.
The EUROArray APOE Direct is designed for the molecular genetic determination of the APOE alleles ε2, ε3 and ε4, especially within the framework of differential diagnosis and/or early recognition of late-onset sporadic Alzheimer’s disease and type III hyperlipoproteinemia. Moreover, arteriosclerosis and other vascular diseases (coronary heart disease, stroke) are associated with the presence of particular APOE alleles.
The test allows fast and simple determination of the APOE gene variantsε2, ε3 and ε4 in a single test. The direct method enables the direct use of whole blood samples and eliminates the need for time and cost-intensive DNA isolation.