DNA Methylation Pattern of Gene Promoters of MB-COMT, DRD2, and NR3C1 in Turkish Patients Diagnosed with Schizophrenia

OBJECTIVE: We aim to evaluate the methylation status of membrane-bound catechol-O-methyltransferase (MB-COMT) promotor, dopamine receptor D2 (DRD2), and nuclear receptor subfamily 3 group C member 1 (NR3C1) gene in patients with SCZ by comparing healthy controls. METHODS: A sample of 110 patients with SCZ and 100 age- and sex-matched healthy volunteers was included in the study. The interview was started by filling out data forms that included sociodemographic and clinical information. The Structured Clinical Interview for DSM-IV Axis I Disorders was used to confirming the diagnosis according to DSM-IV-TR criteria. Then the patients were evaluated with the Positive and Negative Symptoms Scale in terms of symptom severity. Methylation-specific polymerase chain reaction was used to determine the methylation status of MB-COMT promotor, DRD2, and NR3C1 gene from DNA material. RESULTS: When we compared the percentages of MB-COMT promotor, DRD2, and NR3C1 gene methylation status in SCZ patients with the healthy control group, the percentages of MB-COMT promotor (OR 0.466; 95% CI 0.268−0.809; p = 0.006), DRD2 (OR 0.439; 95% CI 0.375−0.514; p < 0.001), and NR3C1 (OR 0.003; 95% CI 0.001−0.011; p < 0.001) gene methylation status of SCZ was found to be significantly different from the control group. Whereas unmethylation of MB-COMT promotor and NR3C1 genes were associated with SCZ, the partial methylation of the DRD2 gene was related to the SCZ. CONCLUSION: The MB-COMT promotor, DRD2, and NR3C1 gene methylation status may be associated with the SCZ in the Turkish population.