Abnormality of the immune system may play an important role in the pathogenesis of schizophrenia (SCZ). We aim to investigate the relationship between clinical features of SCZ and tumor necrosis factor-alpha (TNF-α) −238 G/A, −308 G/A polymorphisms in SCZ patients by comparing genotype distributions of TNF-α gene polymorphisms between patients and healthy controls. A sample of 113 patients with SCZ and 104 healthy volunteers was included in the study. SCID-I was used to confirming the diagnosis according to DSM-IV-TR criteria. We evaluated the patients with some scales and data forms in terms of clinical features, symptom severity, level of insight, suicidal behavior, and treatment response. PCR-RFLP was used to determine TNF-α gene polymorphisms from DNA material. The distributions of TNF-α − 238 G/A and TNF-α − 308 G/A polymorphisms of the patients diagnosed with SCZ were not significantly different from the control group. There was a significant difference in the TNF-α − 238 G/A genotype distributions between treatment-resistant and treatment-responsive SCZ patients. Again, the distributions of TNF-α − 238 G/A genotype of attempted suicide patients in SCZ were significantly different from the non-attempted suicide of SCZ patients. Whereas TNF-α − 238 G/A and −308 G/A polymorphisms were not associated with SCZ, TNF-α − 238 G/A polymorphism may be related to treatment resistance and attempted suicide in SCZ patients in the Turkish population.

Synthetic cannabinoids (SC) are psychoactive drugs that generally produce more severe clinical outcomes compared to Δ9-tetrahydrocannabinol. This study aimed to evaluate the relationship between clinical features of synthetic cannabinoid use disorder (SCUD) and COMT (rs4680), CNR2 (rs2501432), CNR2 (rs2229579), UCP2 (rs659366), and IL-17 (rs763780) gene variants in SCUD patients by comparing the genotype distributions of gene variants between patients and healthy controls. Based on the DSM-5 criteria, 94 patients with SCUD, confirmed with a positive urine test, and 95 healthy volunteers were included in the study. Self-mutilation, suicidal behavior, psychotic symptoms, drug-induced psychosis, tobacco use disorder (TUD) or alcohol use disorder (AUD) comorbidity, and family history of TUD or AUD were evaluated in all patients. PCR-RFLP was used to identify gene variants from DNA material. The distributions of CNR2 (rs2229579) and UCP2 (rs659366) variants were significantly different in patients diagnosed with SCUD compared to the control group. SC-related psychotic symptoms were associated with the IL-17 (rs763780) variant in SCUD patients who had an onset of SC usage under 18 years of age. While the COMT Val108Met gene variant was related to self-mutilation, the COMT Val158Met variant was associated with attempted suicide. In addition, in SCUD patients, the UCP2 (rs659366) variant was associated with a family history of AUD or TUD. In summary, CNR2 (rs2229579) and UCP2 (rs659366) variants were associated with SCUD. While SC-related psychotic symptoms were related to the IL-17 (rs763780) variant, the COMT variants were associated with self-mutilation or attempted suicide in SCUD patients.

This study aimed to investigate the possible role of uncoupling protein 2 (UCP2) gene polymorphisms in childhood obesity and related metabolic disorders. Obese patients (n=100) and healthy controls (n=100) were analyzed for -866G>A and insertion/deletion (I/D) polymorphisms of the UCP2 gene by polymerase chain raction and/or restriction fragment length polymorphism. UCP2 I/D polymorphism showed an association with obesity. The insertion homozygous genotype (II) was higher in obese patients (p=0.0001), while the DD genotype was higher in controls (p=0.0034). Body mass index and relative weight were lower in patients carrying the A allele of the -866G>A polymorphism (p=0.021 and p=0.047, respectively). There was an association between insulin resistance and -866A allele carrier patients with consanguineous parents (p=0.005). Insertion homozygous genotype and the allele of I/D polymorphism were found to be risk factors for childhood obesity and related metabolic disorders. The -866A allele was associated with susceptibility to central adiposity, hypercholesterolemia, hypertriglyceridemia and insulin resistance.