Background: Conventional polygenic risk score (PRS) summarizes genetic risk throughout the genome and lacks biological specificity. Here, leveraging human brain single nucleus RNA sequencing (sNuc-Seq) data, we introduce a new method to capture cell-type specific Alzheimer’s disease (AD) PRS, and implicate different cell types in distinct disease processes in preclinical AD.
Method: Cognitively unimpaired (CU) older adults of European descent who participated in the Anti-Amyloid Treatment in Asymptomatic Alzheimer’s (A4) study screening PET were included in this study. Cortical amyloid-β burden (Aβ) was quantified as cortical composite SUVR from the florbetapir PET. Screening cognition was measured with Preclinical Alzheimer Cognitive Composite (PACC). We defined cell type-specific genes as genes expressed higher in a given cell type (FDR