06 Mar 20. Featured Paper
DNA methylation & brain structure & function across the life course: a systematic review.
Link to paper on Elsevier
Emily N.W.Wheater, David Q.Stoye, Simon R.Cox, Joanna M.Wardlaw, Amanda J.Drake, Mark E.Bastin, James P.Boardman
MRI has enhanced our capacity to understand variations in brain structure & function conferred by the genome.
We identified 60 studies that report associations between DNA methylation (DNAm) & human brain structure/function.
Forty-three studies measured candidate loci DNAm; seventeen measured epigenome-wide DNAm.
MRI features included region-of-interest & whole-brain structural, diffusion & functional imaging features.
The studies report DNAm-MRI associations for: neurodevelopment & neurodevelopmental disorders; major depression & suicidality; alcohol use disorder; schizophrenia & psychosis; ageing, stroke, ataxia & neurodegeneration; post-traumatic stress disorder; & socio-emotional processing.
Consistency between MRI features & differential DNAm is modest.
Sources of bias: variable inclusion of comparator groups; different surrogate tissues used; variation in DNAm measurement methods; lack of control for genotype & cell-type composition; & variations in image processing.
Knowledge of MRI features associated with differential DNAm may improve understanding of the role of DNAm in brain health & disease, but caution is required because conventions for linking DNAm & MRI data are not established, & clinical & methodological heterogeneity in existing literature is substantial.