PCR-RFLP method optimization for monoamine oxidase a (MAOA) RS1465108 polymorphism and determination of the effect of this polymorphism on aggression in patients with schizophrenia

Schizophrenia is a serious illness in which individuals are alienated from society due to positive symptoms such as hallucinations and delusions, or negative symptoms such as asocial behavior, blunted affect, and inability to express themselves. It has been reported that the incidence of aggression in patients with schizophrenia is higher than in the general population. Aggression in patients with schizophrenia has different factors, including genetic variations. The MAOA gene is one of the genetic factors discussed to affect aggression in schizophrenia. Therefore, in this master's thesis, the effect of MAOA rs1465108 polymorphism on aggression in patients with schizophrenia was researched for the first time in the Turkish population. Sixty-one schizophrenia patients were included in the study. The Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) method was optimized for the MAOA rs146408 polymorphism and the genotypes of the patients were analyzed using this method. Aggression levels of the patients were evaluated using the Buss-Perry Aggression Questionnaire. In addition, other factors factors such as suicide probability, childhood trauma, and impulsivity that may affect aggression were examined with the Suicide Probability Scale, the Childhood Trauma Questionnaire, and the Barratt Impulsivity Scale. Genotype frequencies of MAOA rs1465108 polymorphism in schizophrenic patients were determined as 26.2% for AA (homozygous wildtype), 16.4% for AG (heterozygous), and 57.4% for GG (homozygous variant). It was found that there was no significant difference between genotypes in terms of Buss-Perry Aggression Questionnaire scores (p>0.05). However, a statistically significant association was found between the MAOA rs1465108 polymorphism and the anger/impulsivity sub-dimension of the Suicide Probability Scale (p<0.05). In conclusion, it was determined that MAOA rs1465108 polymorphism had no effect on aggression in Turkish schizophrenia patients.