Increased Aβ42/Aβ40 ratio and/or increased Aβ production (Tanzi, 2012). Rare APP A673T mutant confers protection against AD pathology (Peacock et al., 1993; Hashimoto and Matsuoka, 2014) Pattern and progression of amyloid plaque deposition is largely identical to SAD. However, mutations within the Aβ sequence can cause increased deposition in the vasculature (Pilotto et al., 2013). The gene discussed is APP; the disease is Alzheimer disease.