A study investigating if altered DNA methylation in SNCA intron 1 is a mechanism that results in PD and dementia with Lewy bodies (DLB) found that Dnmt1 expression is reduced in the nuclear compartment of postmortem brain samples from PD and DLB patients as well as in brain samples from α-synuclein transgenic mouse models. This evidence concerns the gene DNMT1 and Lewy body dementia.