BDNF val66met polymorphism is associated with age at onset and intensity of symptoms of paranoid schizophrenia in a Polish population.

The brain-derived neurotrophic factor (BDNF) is one of the candidate genes for schizophrenia. There is evidence that val66met polymorphism may be involved in the pathophysiology of schizophrenia. The authors genotyped val66met (rs6265) polymorphism of the BDNF gene in 208 inpatients with paranoid schizophrenia and 254 control subjects in a Polish population. There was no association between val66met polymorphism and development of paranoid schizophrenia in either men or women. However, an association was found between this polymorphism and age at onset and psychopathology of paranoid schizophrenia. Men with the val/met genotype had an earlier age at onset, and the val/val genotype predisposed to more severe symptoms, particularly on the General Psychopathology Scale of the Positive and Negative Symptoms Scale (PANSS-G). The analysis of PANSS single items has shown that patients with the val/met genotype had higher scores on a hallucinatory behavior item than those with other genotypes.