title: Association of the brain-derived neurotrophic factor gene and bipolar disorder with early age of onset in mainland China.
abstract: Several evidences have suggested that the brain-derived neurotrophic factor (BDNF) gene may be involved in the pathogenesis of bipolar disorder (BPD), but not all studies get the same result. The paper investigated two genetic polymorphisms of BDNF, C-270T and Val66Met, in a case-control design for their association with BPD. Sixty-seven patients of early age of onset and 130 patients of late age of onset were selected for study and 208 healthy individuals were used as controls. No significantly statistical differences of these two polymorphisms were found in genotypes or allele frequencies between either overall patients or late age of onset patients and normal control subjects. However, the frequency of the Val allele of the Val66Met polymorphism was found to have significantly increased in the subgroup patients with early age of onset as compared with the controls (genotype: chi(2)=6.602, d.f.=2, P=0.037; allele: chi(2)=6.223, d.f.=1, P=0.015). The study demonstrates that the BDNF C-270T and Val66Met polymorphisms are unlikely to contribute to the genetic predisposition to BPD as a whole. But Val66Met may be associated with susceptibility to the early age of onset subset of the disorder, further studies designed to explore the relationship in a larger population may be warranted.
authors.affiliation: Department of Psychiatry, Renmin Hospital, Wuhan University, Jiefang Road 238#, Wuhan 430060, PR China.
authors.forename: Jihua
authors.initials: J
authors.lastname: Tang
authors.forename: Ling
authors.initials: L
authors.lastname: Xiao
authors.forename: Chang
authors.initials: C
authors.lastname: Shu
authors.forename: Gaohua
authors.initials: G
authors.lastname: Wang
authors.forename: Zhongchun
authors.initials: Z
authors.lastname: Liu
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Wang
authors.forename: Huiling
authors.initials: H
authors.lastname: Wang
authors.forename: Xueguang
authors.initials: X
authors.lastname: Bai
mesh_terms: D000328:Adult; D017668:Age of Onset; D001714:Bipolar Disorder / Q000235:genetics*; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics*; D002681:China / Q000208:ethnology; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D008297:Male; D008715:Methionine / Q000235:genetics; D008875:Middle Aged; D011110:Polymorphism, Genetic / Q000235:genetics*; D014633:Valine / Q000235:genetics
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D008715:Methionine; D014633:Valine