The role of demethylation of CpGs within SNCA intron 1 in the etiology of PD and DLB mediated by SNCA dysregulation was previously studied (Jowaed et al., 2010; Matsumoto et al., 2010; Desplats et al., 2011; Ai et al., 2014; Funahashi et al., 2016; Yoshino et al., 2016). Here, SNCA is linked to Lewy body dementia.