[Molecular-genetic study of early-onset schizophrenia].

Schizophrenia with early onset is a relatively rear form of the disease which characterized by severe chronic course and poor outcome. In the present paper, we studied several genes possibly involved in the pathogenesis of this form. These are genes for brain-derived neurotrophic factor (Val66Met polymorphism), serotonin transporter (5-HTTLPR), serotonin receptor type 2A (T102C) and dopamine receptor D2 (Taq1A). Sixty-five patients (age at onset before 15 years) and 111 healthy controls were included in the study. Out of all genes tested, the association was found only for the Val66Met BDNF polymorphism. Frequency of the ValVal genotype was higher in the group of patients (p=0.03; OR 2.1 CI 1.1-4.0) compared to the controls. These results were consistent with our previous study which was carried out on the sample of schizophrenic patients with later age of disease onset. In this study, the frequency of the ValVal genotype was higher only in the group of patients with chronic schizophrenia compared to the controls. It is concluded that the ValVal BDNF genotype may be considered as a marker of schizophrenia with more severe course.