Lack of association between BDNF Val66Met gene polymorphism and late-onset depression in a Chinese Han population.

Val66Met polymorphism in the brain-derived neurotrophic factor (BDNF) gene has been suggested to be associated with major depressive disorder (MDD). There were a few reports of the relationship between the variant and late-onset depression (LOD) in Chinese Han population.To investigate the relationship among BDNF Val66Met gene variants, BDNF plasma level and LOD.Chinese Han patients with LOD (n = 99) and control subjects (n = 110) were assessed for BDNF Val66Met gene polymorphism. BDNF plasma level was tested only in LOD.There were no significant differences in genotypes and allele frequencies between cases and controls (p = 0.744 and p = 0.845, respectively). Plasma BDNF level also did not show significant differences in three genotypes in LOD (p = 0.860).The Val66Met polymorphism in BDNF gene may not confer susceptibility to LOD in Chinese Han population.