Evaluation of gene-gene interaction between the interleukin (IL)-2 and IL-2RA gene polymorphisms in schizophrenia patients in the Turkish Population.

OBJECTIVES: To evaluate the genetic polymorphisms in IL-2 and IL-2RA genes in schizophrenia (SCZ) patients by comparing them with healthy controls. METHODS: A sample of 127 patients with SCZ and 100 healthy volunteers were included in the case-control study. These individuals were consecutively selected from the Malazgirt State Hospital Psychiatry Outpatient Clinic in Mus, Turkey, over the three months from October 2020 to December 2020. The Structured Clinical Interview for DSM-5 Disorders, Clinician Version (SCID-5-CV) was used to confirm the diagnosis according to the DSM-5 criteria. In addition, polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to determine gene polymorphisms from DNA material. RESULTS: Our findings indicated significant differences in the IL-2 genotype and allele frequencies between SCZ patients and the healthy control group. Specifically, the frequency of the homozygous GG genotype was notably higher in SCZ patients compared to the control group. Conversely, when comparing the IL-2RA genotype and allele frequencies of SCZ patients with the control group, no statistically significant differences were observed between the 2 groups. When compared to individuals with other genotypes, interaction analysis indicated that carriers of the GG/AG (IL-2/IL-2RA) genotype demonstrated a significantly increased risk of SCZ. CONCLUSION: In light of the analyses, our study indicates that while the IL-2 genotype polymorphism may be considered a risk factor for developing SCZ, the IL-2RA variant was not associated with SCZ among Turkish patients.

Association of the Uncoupling Protein 2-866 G/A Polymorphism with Family History and Duration of Tobacco Use Disorder in a Turkish Population.

Background: A variety of substances cause neurotoxicity by increasing intracellular oxidative stress, followed by mitochondrial dysfunction. Uncoupling proteins (UCPs) act as membrane transport proteins and reduce reactive oxygen products and mitochondrial calcium influx. We aimed to study UCP2-866 G/A gene polymorphism in tobacco use disorder (TUD) by comparing genotype distributions between TUD patients and healthy controls considering clinical parameters. Methods: One hundred eighteen patients with TUD and 96 healthy volunteers were included in the study. The diagnosis of the patients were then confirmed, based on the DSM-5 criteria. Polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) were used to determine UCP2 gene polymorphism. Results: Our results demonstrated that the UCP2 genotype distribution and allele frequencies of the TUD patient group were significantly different from those of the control group. When the UCP2 genotype and the allele frequency distributions were compared between the two groups according to the family history of TUD in the patient group, the UCP2 genotype and allele frequency distributions were significantly different. The GG genotype or G allele percentage was significantly higher in patients with a family history of TUD, than the patients without a family history of TUD. Comparing clinical parameters based on the UCP2 genotype, the disorder's duration was significantly different between the groups of UCP2 genotype. The duration of TUD was significantly shorter in patients with GG genotype than other genotypes. Conclusions: In summary, the UCP2-866 G/A gene polymorphism might be associated with family history and duration of TUD in Turkish patients.