Catechol-O-methyltransferase gene promoter methylation as a peripheral biomarker in male schizophrenia.

As an epigenetic modification, DNA methylation may reflect the interaction between genetic and environmental factors in the development of schizophrenia (SCZ). Catechol-O-methyltransferase (COMT) gene is a promising candidate gene of SCZ. In the present study, we investigate the association of COMT methylation with the risk of SCZ using bisulfite pyrosequencing technology. Significant association between DNA methylation of COMT and the risk of SCZ is identified (P=1.618e-007). A breakdown analysis by gender shows that the significance is driven by males (P=3.310e-009), but not by females. DNA methylation of COMT is not significantly associated with SCZ clinical phenotypes, including p300 and cysteine level. No interaction is found between COMT genotypes and the percent methylation of this gene. Receiver operating characteristic (ROC) curve shows that DNA methylation of COMT is able to predict the SCZ risk in males (area under curve [AUC]=0.802, P=1.91e-007). The current study indicates the clinical value of COMT methylation as a potential male-specific biomarker in SCZ diagnosis.