Alzheimer's disease risk variants modulate endophenotypes in mild cognitive impairment

Alzheimers Dement. 2016 Aug;12(8):872-81. doi: 10.1016/j.jalz.2016.01.006. Epub 2016 Feb 26.

Abstract

Introduction: We evaluated the effect of Alzheimer's disease (AD) susceptibility loci on endophenotypes closely related with AD pathology in patients with mild cognitive impairment (MCI).

Methods: We selected 1730 MCI patients from four independent data sets. Weighted polygenic risk scores (PGS) were constructed of 18 non-apolipoprotein E (APOE) AD risk variants. In addition, we determined APOE genotype. AD endophenotypes were cognitive decline over time and cerebrospinal fluid (CSF) biomarkers (aβ, tau, ptau).

Results: PGS was modestly associated with cognitive decline over time, as measured by mini-mental state examination (MMSE) (β ± SE:-0.24 ± 0.10; P = .012), and with CSF levels of tau and ptau (tau: 1.38 ± 0.36, P = 1.21 × 10(-4); ptau: 1.40 ± 0.36, P = 1.02 × 10(-4)).

Discussion: In MCI, we observed a joint effect of AD susceptibility loci on nonamyloid endophenotypes, suggesting a link of these genetic loci with neuronal degeneration in general rather than with Alzheimer-related amyloid deposition.

Keywords: Alzheimer's disease; Endophenotypes; Genetic risk variants; Mild cognitive impairment; Polygenic risk score.

Publication types

  • Meta-Analysis
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Alzheimer Disease / cerebrospinal fluid
  • Alzheimer Disease / diagnosis
  • Amyloid beta-Peptides / cerebrospinal fluid
  • Apolipoproteins E / genetics
  • Cognitive Dysfunction / cerebrospinal fluid*
  • Cognitive Dysfunction / complications*
  • Cognitive Dysfunction / genetics
  • Cohort Studies
  • Datasets as Topic / statistics & numerical data
  • Endophenotypes / cerebrospinal fluid*
  • Female
  • Humans
  • Male
  • Mental Status Schedule
  • Middle Aged
  • Multifactorial Inheritance / genetics*
  • Neuropsychological Tests
  • Odds Ratio
  • Polymorphism, Single Nucleotide / genetics
  • Statistics, Nonparametric

Substances

  • Amyloid beta-Peptides
  • Apolipoproteins E