title: No association between the brain-derived neurotrophic factor (BDNF) Val66Met polymorphism and schizophrenia in Asian populations: Evidence from a case-control study and meta-analysis.
abstract: Brain-derived neurotrophic factor (BDNF) is a nerve growth factor that plays an important role in the development and maintenance of adult neurons and is important regulator of synaptic plasticity in human brain. It has been reported that there are alterations in BDNF levels in the brains of patients with schizophrenia. It has also been reported that transneuronal transfer of BDNF is dependent on neuronal activity, suggesting that BDNF plays an important role in neurotransmission. A single nucleotide polymorphism (SNP) in the BDNF gene that causes a valine to methionine substitution at codon 66 (Val66Met) has been demonstrated to affect human memory and hippocampal function. A possible positive association between the BDNF Val66Met polymorphism and schizophrenia has also been shown in Scottish and Spanish populations. Furthermore, the BDNF Val66Met polymorphism has been implicated in the age of onset of schizophrenia. In the present study, we attempted to replicate these findings in a Japanese case-control sample (211 patients with schizophrenia and 205 controls). We did not find an association between the BDNF Val66Met polymorphism and schizophrenia. An association between the Val66Met polymorphism and age of onset was not observed either. Furthermore, a meta-analysis including the present and previous Asian studies comparing 2059 patients with schizophrenia and 2765 controls also revealed no significant association between the BDNF Val66Met polymorphism and schizophrenia. Our results do not support a significant role for the BDNF Val66Met polymorphism in the development of schizophrenia in Asian populations.
authors.affiliation: Department of Psychiatry, School of Medicine, University of Occupational and Environmental Health, Yahatanishi-ku, Kitakyushu 807-8555, Japan. naoe_yui@yahoo.co.jp
authors.forename: Yui
authors.initials: Y
authors.lastname: Naoe
authors.forename: Takahiro
authors.initials: T
authors.lastname: Shinkai
authors.forename: Hiroko
authors.initials: H
authors.lastname: Hori
authors.forename: Yuko
authors.initials: Y
authors.lastname: Fukunaka
authors.forename: Kensuke
authors.initials: K
authors.lastname: Utsunomiya
authors.forename: Shinichi
authors.initials: S
authors.lastname: Sakata
authors.forename: Chima
authors.initials: C
authors.lastname: Matsumoto
authors.forename: Kazuko
authors.initials: K
authors.lastname: Shimizu
authors.forename: Rudi
authors.initials: R
authors.lastname: Hwang
authors.forename: Osamu
authors.initials: O
authors.lastname: Ohmori
authors.forename: Jun
authors.initials: J
authors.lastname: Nakamura
mesh_terms: D000328:Adult; D044466:Asian People / Q000706:statistics & numerical data; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics*; D016022:Case-Control Studies; D004252:DNA Mutational Analysis / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D015201:Meta-Analysis as Topic; D008715:Methionine / Q000235:genetics*; D008875:Middle Aged; D011110:Polymorphism, Genetic; D012559:Schizophrenia / Q000235:genetics*; D014633:Valine / Q000235:genetics*
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D008715:Methionine; D014633:Valine