Our observation of a stronger effect of APOE ε4 in individuals under the age of 75 is consistent with previous reports that APOE ε4 exerts its maximal effect on AD risk by the early 70’s, with a reduction in risk after the age of 85 (Jarvik et al., 1995; Farrer et al., 1997). This evidence concerns the gene APOE and Alzheimer disease.