Four differentially methylated regions were identified in monocytes, including a region upstream of RAB32, a gene that has been linked to LRRK2. Methylation upstream of RAB32 correlated negatively with mRNA expression, and RAB32 expression was upregulated in Parkinson’s disease both in our samples and in summary statistics from a previous study. This evidence concerns the gene LRRK2 and Parkinson disease.