Integration of GWAS and brain transcriptomic analyses in a multiethnic sample of 35,245 older adults identifies DCDC2 gene as predictor of episodic memory maintenance

Alzheimers Dement. 2022 Oct;18(10):1797-1811. doi: 10.1002/alz.12524. Epub 2021 Dec 7.

Abstract

Identifying genes underlying memory function will help characterize cognitively resilient and high-risk declining subpopulations contributing to precision medicine strategies. We estimated episodic memory trajectories in 35,245 ethnically diverse older adults representing eight independent cohorts. We conducted apolipoprotein E (APOE)-stratified genome-wide association study (GWAS) analyses and combined individual cohorts' results via meta-analysis. Three independent transcriptomics datasets were used to further interpret GWAS signals. We identified DCDC2 gene significantly associated with episodic memory (Pmeta = 3.3 x 10-8 ) among non-carriers of APOE ε4 (N = 24,941). Brain transcriptomics revealed an association between episodic memory maintenance and (1) increased dorsolateral prefrontal cortex DCDC2 expression (P = 3.8 x 10-4 ) and (2) lower burden of pathological Alzheimer's disease (AD) hallmarks (paired helical fragment tau P = .003, and amyloid beta load P = .008). Additional transcriptomics results comparing AD and cognitively healthy brain samples showed a downregulation of DCDC2 levels in superior temporal gyrus (P = .007) and inferior frontal gyrus (P = .013). Our work identified DCDC2 gene as a novel predictor of memory maintenance.

Keywords: apolipoprotein E stratified analyses; brain transcriptomics; episodic memory trajectories (EMTs); genome-wide association studies; meta-analysis; rare/common genetic variation.

Publication types

  • Meta-Analysis

MeSH terms

  • Aged
  • Alzheimer Disease* / genetics
  • Alzheimer Disease* / metabolism
  • Amyloid beta-Peptides / metabolism
  • Apolipoprotein E4 / genetics
  • Apolipoproteins E / genetics
  • Brain / metabolism
  • Genome-Wide Association Study
  • Humans
  • Memory, Episodic*
  • Microtubule-Associated Proteins
  • Transcriptome

Substances

  • Apolipoprotein E4
  • Amyloid beta-Peptides
  • Apolipoproteins E
  • DCDC2 protein, human
  • Microtubule-Associated Proteins