Archives of Psychiatry and Psychotherapy, 2007; 3 : 5–11 INTRODUCTION Schizophrenia is a psychiatric disease which af- fects 1% of the world’s population. The chronic character of the illness and the damage it caus- es in patients’ cognitive skills, emotions and so- cial functioning provide an impetus for research on the causes of the disease to predict its course and establish possibly effective treatment with few side effects. Previous theories accounting for environmen- tal, genetic, neurodevelopmental, biochemical and immunological or infectious factors seemed to explain, to some degree, the origins of schizo- phrenia. Despite the fact that the risk of develop- ing schizophrenia in general population is sim- ilar, the disease was found to be diagnosed def- initely more frequently within families (approx. 10% more often in the first degree relatives), Association of functional genes polymorphisms of key enzymes in the metabolism of biogenic amines with paranoid schizophrenia susceptibility and the influence of these polymorphisms on PANSS results in antipsychotic treatment Piotr Tybura, Anna Grzywacz, Anna Konopka, Jerzy Samochowiec Summary Introduction: The genetic components of schizophrenia susceptibility are calculated as being 50 %. Aim: We evaluated the frequency of alleles and genotypes of COMT and MAO-A genes polymorphisms in patients with schizophrenia and in the healthy population. We searched for associations between the gen- otypes and PANSS results among patients in a three month-long antipsychotic therapy. Subjects and methods: The study comprised 72 unrelated patients who met ICD–10 criteria for schiz- ophrenia, and 187 unrelated healthy controls. The analysis of COMT and MAO-A genes polymorphisms were performed using the polymerase chain reaction technique (RFLP-restriction fragments length poly- morphism and VNTR-variable number tandem repeats). The severity of psychopathological symptoms was measured using the PANSS (Positive and Negative Schizophrenia Scale). Results: We did not find any association between the genotype of COMT and MAO-A genes polymor- phisms and schizophrenia. We found a statistically significant different allele distribution in MAO gene pol- ymorphism: alleles with three tandem repeats in the promoter region were more frequent among females with schizophrenia. We did not find any association between the genotype of COMT and MAO-A genes polymorphisms and PANSS results in any time periods. Due to a small number of patients in this study the obtained results should be regarded as preliminary. schizophrenia / genetics / PANSS Piotr Tybura, Anna Grzywacz, Anna Konopka, Jerzy Samo- chowiec: Department of Psychiatry Pomeranian Medical University in Szczecin, Poland; Correspondence address: Piotr Tybura; Depart- ment of Psychiatry PAM, 26 Broniewskiego St. , 71–460 Szczecin, Poland; E-mail: piotrtybura@wp.pl; Acknowledgments: The study was conducted owing to the Pfizer Independent Research Grant No. 2005–0039.