The most observed genetic factors for AD-onset are the APOE-ε4 isotype, and mutations in the triggering receptor expressed on myeloid cells 2 (TREM2), APP, presenilin-1 (PSEN1) and presenilin-2 (PSEN2) genes [[55], [56], [57]]. The gene discussed is PSEN1; the disease is Alzheimer disease.