PLCG2 and supranuclear palsy, progressive, 1: Therefore, in this study, we sought to replicate the association with AD previously observed with ABI3 rs616338-T and PLCG2 rs72824905-G in Caucasians, test if this association is also observed in African-Americans, and determine if these variants associate with risk of other neurodegenerative diseases, namely Parkinson’s disease (PD), dementia with Lewy bodies (DLB), progressive supranuclear palsy (PSP) and multiple system atrophy (MSA).