Genetic overlap between vascular pathologies and Alzheimer's dementia and potential causal mechanisms

Alzheimers Dement. 2019 Jan;15(1):65-75. doi: 10.1016/j.jalz.2018.08.002. Epub 2018 Sep 19.

Abstract

Introduction: We sought to examine the genetic overlap between vascular pathologies and Alzheimer's disease (AD) dementia, and the potential mediating role of vascular pathologies between AD-related genetic variants and late-life cognition.

Methods: For 2907 stroke-free older individuals, we examined the association of polygenic risk scores for AD dementia (ADPRSs) with vascular pathologies and with cognition. Mediation analyses addressed whether association between ADPRSs and cognition was mediated by a vascular pathology.

Results: ADPRSs were associated with lobar cerebral microbleeds, white matter lesion load, and coronary artery calcification, mostly explained by single nucleotide polymorphisms in the 19q13 region. The effect of ADPRSs on cognition was partially but significantly mediated by cerebral microbleeds, white matter lesions, and coronary artery calcification.

Discussion: Our findings provide evidence for genetic overlap, mostly due to apolipoprotein E (APOE) gene, between vascular pathologies and AD dementia. The association between AD polygenic risk and late-life cognition is mediated in part via effects on vascular pathologies.

Keywords: Alzheimer's dementia; Causal mediation; Cerebral microbleeds; Cognitive impairment; Coronary calcification; Polygenic risk score; White matter lesions.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, N.I.H., Intramural

MeSH terms

  • Aged
  • Alzheimer Disease / genetics*
  • Alzheimer Disease / pathology
  • Alzheimer Disease / physiopathology
  • Apolipoproteins E / genetics
  • Brain / pathology*
  • Cognitive Dysfunction / genetics
  • Cognitive Dysfunction / pathology
  • Female
  • Humans
  • Male
  • Microvessels / pathology*
  • Neuropsychological Tests
  • Peptide Fragments / genetics
  • Polymorphism, Single Nucleotide
  • Risk Factors
  • White Matter / pathology

Substances

  • Apolipoproteins E
  • Peptide Fragments
  • apolipoprotein E (133-149)