A growing body of evidence indicates the strong association between the Apolipoprotein (APOE4) allele, the increased risk of Alzheimer’s disease (AD), the associations with cognitive and brain volumetric changes from childhood and the increased risk for other neurodegenerative diseases besides AD [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18]. This evidence concerns the gene APOE and early-onset autosomal dominant Alzheimer disease.