Polygenic scores of Core 1 Alzheimer's disease biomarkers predict early cognitive and pathological change

Core 1 biomarkers, such as amyloid positron emission tomography, capture the earliest biological changes leading to Alzheimer's disease (AD). While APOE is a major genetic factor, the contribution of other variants to Core 1 biomarkers remains unclear. The goal of this study was to determine whether genetic regulators of Core 1 biomarker levels predicted AD pathology better than genetic regulators of clinical AD.

Among 955 non-Hispanic White individuals, polygenic scores (PGSs) were built using genome-wide association studies (GWASs) of amyloid PET, plasma tau phosphorylated at threonine 181 (p-tau181), cerebrospinal fluid (CSF) p-tau181, and clinical AD. Hispanic-specific PGSs were constructed in 515 individuals using plasma p-tau181 and clinical AD GWASs. Baseline and longitudinal associations with plasma biomarkers and cognition were assessed, and replication was conducted in separate cohorts.

The Core 1 biomarker PGSs predicted AD pathology and associated cognitive performance better than the AD PGSs in both populations.

The Core 1 PGSs show improved predictive value for AD-related plasma biomarkers and early cognitive changes.

APOE ε4 explained more variance in plasma p-tau217 than in plasma p-tau181. PGSs based on Core 1 biomarkers outperformed AD PGSs in predicting plasma biomarkers and cognitive decline among asymptomatic individuals in non-Hispanic White and Hispanic individuals. However, the improvement in predictive power was modest and may vary by age. While the variance in p-tau181 and p-tau217 explained by individual Core 1 PGSs remains limited, the distinct genetic signals captured by the best-performing PGSs across different Core 1 biomarkers may provide an opportunity for developing an integrative Core 1 PGS that more effectively predicts plasma p-tau181 and p-tau217 levels than AD-based PGS.