Interrogating DNA methylation associated with Lewy body pathology in a cross brain-region and multi-cohort study.

Here, we conduct a large meta-analysis of DNA methylation across multiple cortical brain regions, in relation to increasing burden of Lewy body pathology. Utilizing a dataset of 1205 samples (832 unique donors), we identify 24 false discovery rate significant differentially methylated loci associated with Lewy body pathology, with loci located in UBASH3B and PTAFR, and an intergenic locus passing the genome-wide significance threshold. Ontological enrichment analysis highlights several neurologically relevant traits, including synaptic alterations. We compare methylation signatures between neurodegenerative pathologies and highlight a shared epigenetic profile across Lewy body, Alzheimer's and Huntington's diseases, although the top-ranked loci show disease specificity. Utilizing summary statistics from large-scale genome-wide association studies, we identify significant enrichment of DNA methylation differences with respect to increasing Lewy body pathology in the SNCA genomic region. We also identify specific relationships between genetic risk variants for Lewy body dementia and Parkinson's disease to methylation quantitative trait loci in the SNCA 5' region and expression of alternative transcript isoforms.