Lack of association between catechol-O-methyltransferase and schizophrenia in a Turkish population

Objective: Catechol-O-methyltransferase (COMT) is the key molecule in the catabolism of catecholamines like dopamine which is an important molecule in schizophrenia. Due to its function and location COMT gene is a strong candidate gene for schizophrenia. The aim of this study was to investigate the possible associations of 3 COMT single nucleotide polymorphisms (SNPs) and schizophrenia in our population. COMT enzyme activity is regulated by a widely known Val158Met polymorphism (rs4680), along with the variation of the SNPs rs737865 and rs165599. Methods: Val158Met polymorphism (rs4680), the SNPs rs737865 and rs165599 were the targets of this study. The study was performed with 96 patients (66 male and 30 female) and 100 controls (47 male and 53 female) from Malatya region on eastern part of Turkey by using TaqMan genotyping assays. Results: We couldn't find a significant difference between the schizophrenia patients and normal controls for any of the SNPs that were studied. The genotype frequencies in both the patient and control groups satisfied the Hardy-Weinberg equilibrium. No significant gender differences were observed for the SNPs that were investigated. No significant difference was observed in the allele or genotype frequencies as well. Conclusion: COMT gene doesn't appear to be a risk factor in this population of schizophrenia patients in Turkey.