CHAT and Alzheimer disease: Recently, several studies, including the large-scale genome-wide association studies (GWAS) of AD, have reported some susceptibility genes such as Apolipoprotein E (ApoE), Bridging Integrator 1 (BIN1), Clusterin (CLU), complement component receptor 1 (CR1), and choline O-acetyltransferase (CHAT) [7–10].