Other risk factors for sporadic AD, which constitute more than 95% of AD cases, are the presence of the ε4 allele for apolipoprotein E (APOE) (Morris et al., 2017), hypertension, atherosclerosis, hypercholesterolemia, traumatic brain injury, among others (Edwards et al., 2019). Here, APOE is linked to familial hypercholesterolemia.