PSEN1 and early-onset autosomal dominant Alzheimer disease: Alzheimer disease is linked to variants in amyloid-β-protein precursor (APP), presenilin-1, and presenilin-2 (PS1 and PS2) genes (Yan et al., 1995; Barglow and Cravatt, 2007), which lead to neuropathological characteristics of advanced accumulation of β-amyloid in the brain and the dyruption of synaptic LTP transmissions (Shankar et al., 2008).