No association between the brain-derived neurotrophic factor gene and schizophrenia in a Japanese population

Brain-derived neurotrophic factor (BDNF) plays important roles in the survival, maintenance and growth of neurons. Several studies have indicated that BDNF is likely to be related to the pathogenesis of schizophrenia. Recent genetic analyses have revealed that BDNF gene polymorphisms are associated with schizophrenia, although contradictory negative findings have also been reported. To assess whether three BDNF gene polymorphisms (rs988748, C132T and rs6265) could be implicated in vulnerability to schizophrenia, we conducted a case-control association analysis (349 patients and 423 controls) in Japanese subjects. We found no association between these BDNF gene polymorphisms and schizophrenia using both single-marker and haplotype analyses. The results of the present study suggest that these three BDNF gene polymorphisms do not play major roles in conferring susceptibility to schizophrenia in a Japanese population. However, further studies assessing the associations between these BDNF gene polymorphisms and schizophrenia should be performed in several other ethnic populations.