Identifying Cognitive Resilience Related Genes Among Genetic Risk Loci of Alzheimer’s Disease

Abstract

AbstractBackgroundCognitive resilience (CR) in the context of Alzheimer’s disease (AD) describes the ability to maintain cognitive function despite the presence of neuropathology (Hohman et al., 2016). While most studies have focused on investigating genetic risk factors for developing AD, we here examined the association of most robust risk loci (Bellenguez et al., 2021) with CR using a neuroimaging‐based approach that incorporates measures of brain atrophy and cognition into a quantitative CR metric (van Loenhoud, 2017).MethodWe performed magnetic resonance imaging (3T) and DNA testing on n = 440 amyloid‐positive individuals in different clinical stages of AD. Employing a global cognitive composite score, we predicted gray matter volume (GM) in each voxel, adjusted for sex, age, premorbid intracranial volume, disease stage, and scanner type. To operationalize CR, W‐scores were computed for each individual based on the standardized individual difference between predicted and observed GM within temporoparietal (TP) and whole brain (WB) masks. In this approach, positive W‐scores reflect low CR, while negative W‐scores reflect high CR. A total of 83 genetic risk variants for AD (Bellenguez et al., 2021) were each tested for their association with W‐scores in a linear regression model corrected for population substructure (PC1‐5).ResultWe found an association for 6 genetic loci, of which variants rs113706587 in gene RASGEF1c and rs6943429 in gene UMAD1 were associated with higher CR (TP: p<0.01, p<0.02; WB: p<0.02, p<0.01). As expected, APOEe4 was associated with low CR (TP: p<0.01, WB: p<0.01), as were genetic markers of genes CLU, MINDY2 (WB: p<0.04, p<0.04), and BCKDK (WB: p<0.05, TP: p<0.04). Importantly, no association was found between APOEe2 and CR (WB: p = 0.195, TP: p = 0.139).ConclusionAmong genetic risk‐loci for AD, we identified two genetic variants associated with cognitive resilience in amyloid‐positive individuals. Interestingly, APOEe4 associated with low CR, as did genes CLU, MINDY2, and BCKDK, indicating anti‐resilience – possibly through accelerating mechanisms. In addition, our results suggest that CR against AD is independent of the protective relationship found between APOEe2 and developing AD, highlighting the relevance of investigating the mechanisms behind CR.