CHRM1 and Alzheimer disease: Pathway analysis incorporating the DMPs showed that aberrantly methylated retrotransposon loci were involved in multiple pathways relating to dementia (Fig 4B and 4C); the most significant pathway (by p value) was the muscarinic acetylcholine receptor 1 and 3 signalling pathway (p = 0.007), which is implicated in AD development and cognitive decline.