Polymorphisms in the
brain-derived neurotrophic factor (
BDNF) gene have been indicated to be associated with
schizophrenia. Previous studies have suggested that val66met polymorphism may increase the risk for
schizophrenia, although other studies have not confirmed this association. Decreased
BDNF levels in the brain and the serum of patients with
psychotic disorders have been reported in first episode psychotic (
FEP) patients. In our study we investigated the potential genetic association of this polymorphism with
schizophrenia in a sample of 38
FEP patients with
schizophrenia compared with a sample of 21 normal controls. Furthermore, we assessed serum
BDNF levels and investigated whether there was an association between this polymorphism and alterations of serum
BDNF levels between the investigated groups. There was a significant difference in genotyped frequencies between cases and controls (p=0.030). The homozygous carriers
Met/Met were over-represented in the
schizophrenia group (13/31, 41.9%), compared to controls (2/19, 10.5%). The serum
BDNF levels in the sample of
FEP patients was significantly reduced compared to controls (18.87±8.23 ng/mL vs 29.2±7.73ng/mL, U=140, p=0.0). No association was found between alterations of serum
BDNF levels and Val66Met polymorphism in the group of patients (p=0.198). Negative correlations were shown between serum
BDNF levels of the patients and the PANSS Negative subscale scores (p=0.015). There was found no significant difference between genotypes and memory scores in the sample of patients. Our findings indicate that serum
BDNF levels at the onset of
schizophrenia and
BDNF Val66Met variant may be susceptibility risk factors for
schizophrenia.