Dementia with Lewy bodies post-mortem brains reveal differentially methylated CpG sites with biomarker potential

Dementia with Lewy bodies (DLB) is a common form of dementia with known genetic and environmental interactions. However, the underlying epigenetic mechanisms which reflect these gene-environment interactions are poorly studied. Herein, we measured genome-wide DNA methylation profiles of post-mortem brain tissue (Broadmann area 7) from 15 pathologically confirmed DLB brains and compared them with 16 cognitively normal controls using Illumina MethylationEPIC arrays. We identified 17 significantly differentially methylated CpGs (DMCs) and 17 differentially methylated regions (DMRs) between the groups. The DMCs are mainly located at the CpG islands, promoter and first exon regions. Genes associated with the DMCs are linked to “Parkinson disease” and “metabolic pathway”, as well as the diseases of “severe intellectual disability” and “mood disorders”. Overall, our study highlights previously unreported DMCs offering insights into DLB pathogenesis with the possibility that some of these could be used as biomarkers of DLB in the future. Bisulphite converted DNA from the 15 DLB brain samples and 16 normal brain samples were hybridised to the Illumina Infinium Human MethylationEPIC Beadchip