Abstract
INTRODUCTION: Polygenic risk scores (PRSs) for Alzheimer's disease (AD) capture an individual's genetic susceptibility to AD. Although thoroughly studied in older populations, there exists a notable gap in comprehensively exploring the association of AD PRS with early brain development. METHODS: We examined longitudinal brain magnetic resonance imaging (MRI) data from 348 typically developing children in the RESONANCE cohort. Proportional cerebrospinal fluid (pCSF), white matter (pWM), and gray matter (pGM) volumes were analyzed using functional concurrent regression and Riemannian functional principal component analysis. AD-PRS scores (AD25 and AD54) were computed using genome-wide data. RESULTS: Higher AD PRS was significantly associated with reduced pCSF during early childhood (ages 2.5 to 5.5 years for AD54). Energy and distance-based tests revealed overall significant differences in brain volume trajectories between moderate and low AD54 risk groups. DISCUSSION: These findings suggest that genetic risk for late-onset AD is linked to early neurodevelopmental patterns, indicating that AD vulnerability may originate during critical windows of early brain maturation.