Table 1.

This table divides AD into two common types (EOAD and LOAD) and lists their common risk genes and mutation ways respectively

AD type	Gene	Mutation type	Mechanism	Supplement
EOAD/fAD [163]	APP	Val717Ile/London mutation	increase in Aβ42/Aβ40 ratio and total Tau	autosomal-dominant
	PSEN1	missense mutations, small insertions, deletions, and genomic deletions	interfere with the fusion of the γ-secretase complex	PSEN2 carriers may onset later than PSEN1 carriers on an average level	Complete penetrance
	PSEN2	Missense mutations			incomplete penetrance
LOAD	APOE [179]	Over 44 risk loci	See below for details
	TREM2 [225]	R47H mutation	See below for details
	CD33 [187]	rs3865444 and rs12459419 risk variant	inhibit of cellular activity and of functions	N/A
	INPP5D [168]	missense Mutations	Increase plaque-associated microglia	N/A
	SORL1 [173]	Point mutation	Alter APP trafficking at the cell surface	Parkinsonian disease (PD) features