For a long time, APOE E4 gene has been linked to increased risk of Alzheimer's disease although only 15 percent of the population carry this variant. The study team feel that there are other gene variants and/or combination of gene variants occurring in the remaining 85 percent, which may also be associated with an increased Alzheimer's disease risk. They opine that the significance of APOE E2 gene may have been overstated. The new test measures the combined effects of over two dozen gene variants including APOE E4. Each of these, by itself singly, is associated with only a slight risk of Alzheimer's disease.
