EXPRESS: The relationship of the methylation status and polymorphism of glucocorticoid receptor gene (NR3C1) with attempted suicide or non-suicidal self-injury patients in schizophrenia.

We aim to investigate the methylation of NR3C1 gene promotor and NR3C1 BclI polymorphism in schizophrenia (SCZ) patients with attempted suicide or non-suicidal self-injury (NSSI). A sample of 112 patients with SCZ were included in the study. SCID-I was used to confirm the diagnosis according to DSM-IV-TR criteria. The patients were evaluated by data forms that had sociodemographic, suicidal behavior, and NSSI information. Methylation-specific PCR was used to identify the methylation of the NR3C1 gene. The analysis of the BclI polymorphism of the NR3C1 gene was evaluated by using the PCR-RFLP. Our results revealed that although the NR3C1 gene methylation was not statistically significantly different, there was a significant difference in NR3C1 genotype distribution between the SCZ groups with and without attempted suicide. SCZ patients carrying the CC genotype had a lower risk of attempted suicide (OR: 0.421; 95% Cl: 0.183-0.970; p=.040), while having the GG genotype in SCZ patients was associated with a higher risk of attempted suicide (OR: 3.785; 95% Cl: 1.107-12.945; p=.042). Additionally, due to NSSI in SCZ patients, there were no significant differences in NR3C1 gene methylation and NR3C1 genotype distribution between the groups. We propose that the NR3C1 BclI polymorphism may be associated with attempted suicide in Turkish patients diagnosed with SCZ.