[Molecular-genetic approach to the clinical and nosologic differentiation of schizoaffective disorder].
The aim of the study was to find molecular-genetic variants associated with nosologically independent schizoaffective disorder (SAD) which clinical presentations had been specified earlier. Authors studied a sample of 230 patients including 39 with "nuclear" (nosologically independent) and marginal (intermediate) variants of SAD, 53 with schizophrenia with schizoaffective states and 81 with schizophrenia with affective disorders in the structure of psychotic attacks. In these groups, authors studied the following polymorphisms: 5-HTTLPR, Val66Met BDNF, T102C 5-HTR2a and С677Т MTHFR. Frequencies of genotypes were compared to those in a sample of healthy controls (328 people). It has been shown that the "nuclear" variant has a genetic profile represented by a combination of genetic variants (SS*ValVal*TT*CC) that distinguishes this clinical entity from other groups and controls. The results may be used as an additional criteria for clinical and nosological differentiation of SAD from schizophrenia.