Lin YF, et al. - For 2,907 stroke-free older individuals, researchers studied the genetic overlap between vascular pathologies and Alzheimer's disease (AD) dementia as well as if there is a mediating role played by vascular pathologies between AD-related genetic variants and late-life cognition. Findings suggested a link between polygenic risk scores for AD dementia (ADPRSs) and lobar cerebral microbleeds, white matter lesion load, and coronary artery calcification, which are largely explained by single nucleotide polymorphisms in the 19q13 region. Cerebral microbleeds, white matter lesions, and coronary artery calcification partially, but significantly, mediate ADPRSs influence on cognition. Between vascular pathologies and AD dementia, evidence for genetic overlap, mostly due to apolipoprotein E (APOE) was found. Through effects on vascular pathologies, the relationship between AD polygenic risk and late-life cognition is partially mediated.