Our gene‐wide analysis showed that the first factor was associated with APOE, an important risk‐gene for Alzheimer's disease as demonstrated by GWASs (Jansen et al., 2019; Kunkle et al., 2019; Lambert et al., 2013), so as by studies focused on the association between Alzheimer's disease and APOE genotype (Corder et al., 1993; Farrer et al., 1997; Liu, Kanekiyo, Xu, & Bu, 2013). Here, APOE is linked to early-onset autosomal dominant Alzheimer disease.