PSEN1 and Alzheimer disease: Genome sequencing projects of human AD patients and meta‐analysis of the reports have revealed genes/loci that are frequently mutated in AD patients, that is, AD genetic risk loci (Beecham et al., 2014; Carrasquillo et al., 2015; Chouraki & Seshadri, 2014; Jansen et al., 2019; Kim, 2018; Kunkle et al., 2019; Lambert et al., 2013; Van Cauwenberghe, Broeckhoven, & Sleegers, 2016; Zhang, Gaiteri, et al., 2013), in addition to known familial AD mutations, such as PSEN1/2, APP, and APOE variants.