Early onset AD can also arise from elevated Aβ levels due to altered APP processing caused by mutations in the γ-secretase genes PSEN1 or PSEN2 [2].The accumulation of Aβ peptides is thought to lead to tau hyperphosphorylation, which can result in synaptic dysfunction, neuronal death, and cognitive decline [14]. The gene discussed is APP; the disease is Alzheimer disease.