In brief, we observe higher frequencies of individuals carrying APOE:rs449647-T, 19q13.31:rs10423769-A, APP:rs466433-G, or APP:rs364048-C protective variant alleles alongside either one or two copies of APOE ε4 among African and African Admixed ancestries compared to Europeans for AD, related dementias, and controls. This evidence concerns the gene APOE and Alzheimer disease.