Most prevalent of these, Alzheimer’s disease, has been reported to be caused due to mutations in genes, like APP (Goate and Chartier-Harlin, 1991), presenilins (Scheuner et al., 1996), tau (Hutton et al., 1998), etc. Apolipoprotein E (ApoE), in recent years, have also been shown as one of the risk factors for the disease (Saunders et al., 1993). Here, APOE is linked to early-onset autosomal dominant Alzheimer disease.