PSEN2 and Alzheimer disease: AD, which is characterized by dementia resulting from extensive yet selective neuron death in the neocortex and hippocampus, is the most common NDs with more than 90% of patients being sporadic and less than 10% of AD cases caused by a single genetic mutation in the APP genes (Presenilin 1, Presenilin 2, and Amyloid precursor protein APP) (Lanoiselée et al., 2017). PD is the second most common NDs that affects more than 1% people over age 60.