Although age, sex or other exogenous factors, such as traumatic brain injury or a persons’ lifestyle, are the main causes of Alzheimer’s disease, there is also a rare genetic origin; about 1% of dominantly inherited familiar AD is caused by mutations of the genes coding for the amyloid precursor protein, presenilin-1 and presenilin-2 [12,13,14,15,16]. Here, PSEN2 is linked to Alzheimer disease.