Polymorphism of TPH2 Gene rs120074175 Is Not Associated with Risk Factors of Schizophrenia.

CONTEXT: Polymorphism on tryptophan hydroxylase 2 (TPH2) gene rs120074175 can cause the synthesis of neurotransmitter serotonin in the brain to reduce up to 80%. Reduced serotonin in the brain can cause dopamine release to occur continuously. Excess dopamine in the brain may cause positive symptom of schizophrenia. AIM: The aim of this study was to investigate the genotype distribution of TPH2 rs120074175 gene on patients with schizophrenia at Prof. Dr. Soerojo Magelang Psychiatric Hospital, Indonesia, and the relationship between the genetic polymorphism of the TPH2 rs120074175 gene against risk factors of schizophrenia. SETTINGS AND DESIGN: This was a cross-sectional study. MATERIALS AND METHODS: The method used was amplification refractory mutation system-polymerase chain reaction (ARMS-PCR). Whole blood from healthy subjects and patients with schizophrenia, Wizard genomic deoxyribonucleic acid (DNA) purification kit (Promega, Fitchburg, Wisconsin), PCR master mix (Promega), ARMS-PCR primers, ddH2O, agarose (Thermo Scientific, Seoul, South Korea), Tris, Acetic Acid, EDTA (TAE) 1X, ethidium bromide, loading dye 6×, and DNA ladder (Thermo Scientific) were the materials used. STATISTICAL ANALYSIS: Hardy-Weinberg equilibrium and chi-square (χ2) tests were used. RESULTS: The results showed that both groups (healthy subjects and patients with schizophrenia) at the Prof. Dr. Soerojo Magelang Psychiatric Hospital have a wild-type GG genotype (100%) without anyone having a mutant A allele. CONCLUSION: TPH2 rs120074175 gene polymorphism was not associated with risk factors for schizophrenia.

Single-nucleotide Polymorphism of CTLA-4 (rs5742909) in Correlation with Schizophrenia Risk Factor.

BACKGROUND: Cytotoxic T protein lymphocyte antigen-4 (CTLA-4) plays a key role in regulating the T-cell system, where occurrence of disturbances in the system seen by imbalances in Th1 and Th2 levels is believed to be one of the etiologies of schizophrenia. Single-nucleotide polymorphisms (SNPs) at rs5742909 in the CTLA-4 gene (C→T) might affect the expression level of CTLA-4 protein. AIMS AND OBJECTIVES: The aim of this study was to determine the genotype distribution of the CTLA-4 gene (rs5742909) in patients with schizophrenia at Rumah Sakit Jiwa Prof. Dr. Soerojo Magelang and identify the correlation of these genetic polymorphisms as the risk factors of schizophrenia. MATERIALS AND METHODS: This research was conducted through the stage of submitting ethical approval, primer design, chromosomal DNA isolation, optimization of polymerase chain reaction conditions, and data analysis. RESULTS: Based on the results of the study, the CC genotype was shown in 36 patients (78.26%), TT genotype in 10 patients (21.73%), and no TT genotypes. However, statistical analysis using Fisher's exact and binary logistic regression statistical test showed no significant relationship between genetic polymorphism of the CTLA-4 rs5742909 against risk factors for schizophrenia (P = 0.05; α = 5%). CONCLUSION: SNP at rs5742909, C-to-T-allele transition, was not significant associated with the risk of schizophrenia.