[The molecular-genetic aspects of differentiation of schizoaffective psychosis and attack-like progressive schizophrenia].

To clarify nosologic differences between schizoaffective psychosis (SAP) and attack-like progressive schizophrenia at molecular-genetic level, the genetic polymorphism of serotonin receptor type 2A (5HTR2A), serotonin transporter (5-HTTLRP), and brain-derived neurotrophic factor (BDNF) was studied in 563 patients with schizophrenia (mean age 37.7+/-14.4 years, age at disease onset 26.7+/-11.4 years), and 171 patients with SAP (mean age 30.7+/-11.6 years, age at disease onset 24.9+/-8.5 years). The control group consisted of 536 psychiatrically well subjects. Clinical symptoms and personal features were evaluated as well. By comparison with schizophrenic patients, those with SAP were featured by subtle negative symptoms and personality changes that supported the evidence that SAP is a disorder with a favorable outcome. Molecular-genetic studies revealed higher frequencies of S allele and SS genotype (5-HTTLPR polymorphism), which are thought to be associated with depression and depressive symptoms, and higher frequency of BDNF genotypes, containing Met allele, in combination with 5-HTTLRP genotypes containing L allele, in patients with SAP as compared to the schizophrenic group. C allele and CC genotype (T102C 5-HTR2A polymorphism) frequencies were higher in both groups of patients vs. controls. In conclusion, the results confirm the concept considering SAP an independent nosologic category.