We perform an EWAS of global brain volumes in Generation Scotland using peripherally measured whole blood DNA methylation (DNAm) from two assessments, (i) at baseline recruitment, ~6 years prior to MRI assessment (N=672) and (ii) concurrent with MRI assessment (N=565). Four CpGs at baseline were associated with global cerebral white matter, total grey matter, and whole-brain volume (Bonferroni p≤7.41×10−8, βrange= -1.46x10-6 to 9.59x10-7). These CpGs were annotated to genes implicated in brain-related traits, including psychiatric disorders, development, and ageing. We did not find significant associations in the meta-analysis of the EWAS of the two sets concurrent with imaging at the corrected level.
These findings reveal global brain structural changes associated with DNAm measured ~6 years previously, indicating a potential role of early DNAm modifications in brain structure. Although concurrent DNAm was not associated with global brain structure, the nominally significant findings identified here present a rationale for future investigation of associations between DNA methylation and structural brain phenotypes in larger population-based samples.
This work was supported by the Wellcome Trust [104036/Z/14/Z].
Generation Scotland received core support from the Chief Scientist Office of the Scottish Government Health Directorates [CZD/16/6] and the Scottish Funding Council [HR03006] and is currently supported by the Wellcome Trust [216767/Z/19/Z]. Genotyping of the GS:SFHS samples was carried out by the Genetics Core Laboratory at the Edinburgh Clinical Research Facility, University of Edinburgh, Scotland and was funded by the Medical Research Council UK and the Wellcome Trust (Wellcome Trust Strategic Award “STratifying Resilience and Depression Longitudinally” (STRADL) Reference 104036/Z/14/Z). MCB is supported by a Guarantors of Brain Non-clinical Post-Doctoral Fellowship. AMM is supported by the Wellcome Trust (104036/Z/14/Z, 216767/Z/19/Z, 220857/Z/20/Z) and UKRI MRC (MC_PC_17209, MR/S035818/1). KLE is supported by the NARSAD Independent Investigator Award (Grant ID: 21956). JMW is supported by UK Dementia Research Institute which is funded by the MRC, Alzheimer’s Research UK and Alzheimer’s Society, by the Fondation Leducq (16 CVD 05), and the Row Fogo Centre for Research Into Ageing and the Brain (BRO- D.FID3668413). This work is part of a project that has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 847776.
- DNA methylation
- epigenome-wide association study
- cortical volumes
- Generation Scotland