Variation in global DNA hydroxymethylation with age associated with schizophrenia.

To improve understanding of DNA hydroxymethylation (5hmC) and methylation (5mC) in the development of schizophrenia, this study examined global 5hmC and 5mC levels in peripheral blood DNA of 264 patients with schizophrenia and 221 controls and observed increased 5mC levels in the patients and increased 5hmC levels in male patients but decreased levels in female patients as compared with the controls. The 5mC level displayed a gender-dependent positive correlation with age and the 5hmC level displayed a correlation with age positively in controls but negatively in patients, and their role in the pathogenesis of schizophrenia remains to be elucidated.