We found that, in the progressive mild cognitive impairment group, rs5978930 was associated with total tau levels and rs16947151 was associated with cognitive function scores at baseline and over time, suggesting that ABI3 variants may be associated with cognitive decline and may influence AD onset through tau pathology.
These OR estimates were maintained in the non-overlapping replication AD-control analysis, albeit at reduced significance (ABI3_rs616338-T OR = 1.44, p = 0.12; PLCG2_rs72824905-G OR = 0.66, p = 0.19).
The App <sup>NL-G-F/NL-G-F</sup> cortex also had altered expression of genes (Abi3, Apoe, Bin2, Cd33, Ctsc, Dock2, Fcer1g, Frmd6, Hck, Inpp5D, Ly86, Plcg2, Trem2, Tyrobp) defined as risk factors for AD by genome-wide association study or identified as genetic nodes in late-onset AD.
We observed three new genome-wide significant nonsynonymous variants associated with Alzheimer's disease: a protective variant in PLCG2 (rs72824905: rs72824905" genes_norm="5336">p.Pro522Arg, P = 5.38 × 10<sup>-10</sup>, odds ratio (OR) = 0.68, minor allele frequency (MAF)<sub>cases</sub> = 0.0059, MAF<sub>controls</sub> = 0.0093), a risk variant in ABI3 (rs616338: p.Ser209Phe, P = 4.56 × 10<sup>-10</sup>, OR = 1.43, MAF<sub>cases</sub> = 0.011, MAF<sub>controls</sub> = 0.008), and a new genome-wide significant variant in TREM2 (rs143332484: rs143332484" genes_norm="54209">p.Arg62His, P = 1.55 × 10<sup>-14</sup>, OR = 1.67, MAF<sub>cases</sub> = 0.0143, MAF<sub>controls</sub> = 0.0089), a known susceptibility gene for Alzheimer's disease.