APOE and early-onset autosomal dominant Alzheimer disease: Consequently, the effect of APOE-ε4 on various Alzheimer’s disease biomarkers has been studied extensively over the last decades [reviewed by Belloy et al. (2019)] and modifying demographic factors such as ethnicity and sex have been identified (Farrer et al., 1997; Ungar et al., 2013; Altmann et al., 2014).