Sporadic AD is often accompanied by disorders such as hypercholesterolemia, dyslipidemia, impaired insulin signaling, or impaired cellular energy metabolism [3,4] Furthermore, an increased risk of sporadic AD is associated with the presence of the ε4 allele of apolipoprotein E (APOE ε4) [5], involved in lipid metabolism. Here, APOE is linked to familial hypercholesterolemia.