Gilles de la Tourette syndrome is associated with hypermethylation of the dopamine D2 receptor gene
Several lines of evidence support a “dopaminergic hypothesis” in the pathophysiology of Gilles de la Tourette syndrome (TS). The aim of this study was to investigate for the first time epigenetic changes in DNA methylation in different dopamine genes in adult patients with TS. We included 51 well characterized adult patients with TS (41 males, 10 females, mean age = 35 ± 12.6 years, range, 18–71 years) and compared results with data from a group of 51 sex- and age-matched healthy controls. Bisulfite sequencing was used to measure peripheral DNA methylation of the dopamine transporter (DAT), the dopamine D2 receptor (DRD2), and the catechol-O-methyltransferase (COMT) genes. Compared to healthy controls, patients with TS showed significantly elevated methylation level of the DRD2 gene that positively correlated with tic severity.