Table 1.

Alzheimer’s disease—known causal genes

Gene	Protein	Chromosome	Mutation frequency in early onset	Types of mutations reported	Known function	Pathway
APP	Amyloid precursor protein	21	15%	Missense, duplication, deletions	Neurite outgrowth, adhesion, and axonogenesis	APP processing
PSEN1	Presenilin-1	14	80%	Missense, duplication, deletions	Component of γ-secretase complex; proteolytic cleavage of membrane proteins, including APP	APP processing
PSEN2	Presenilin-2	1	5%	Missense	Component of γ-secretase complex; proteolytic cleavage of membrane proteins, including APP	APP processing