Specifically, 19q13.31:rs10423769-A reduces the risk of AD in Africans, NOCT:rs13116075-G reduces the risk in Africans but increases it in African Admixed ancestry, CASS4:rs6024870-A reduces the risk in Complex Admixed History ancestry, and LRRC37A:rs2732703-G increases the risk in American Admixed ancestry. This evidence concerns the gene CASS4 and Alzheimer disease.