Rs6265
Rs6265, also called Val66Met or G196A, is a gene variation, a single nucleotide polymorphism (SNP) in the BDNF gene that codes for brain-derived neurotrophic factor. Well over a hundred research studies have examined the polymorphism. Association with neuropsychiatric disorders A number of studies have examined the role of this polymorphism in risk of neuropsychiatric disorders , including schizophrenia and depression. It is generally thought that some variants of the polymorphism lead to memory impairment and susceptibility to neuropsychiatric disorders, and a 2007 meta-analysis of case-control studies found a relationship between the SNP and substance-related disorders, eating disorders, and schizophrenia. Another 2007 meta-analysis could, however, find no association between the SNP and schizophrenia or bipolar disorder. Meta-analyses of Alzheimer's disease and Parkinson's disease also indicate that the SNP has little or no association with these diseases. Also inconsistencies in association studies with depression have been noted. The reason for these inconsistent results have been suggested to stem from several sources, with one recent review arguing that statistical artefact, sampling bias, population stratification and uncontrolled gene-environment interactions are likely to underscore this effect . These same authors recently published a report which found that transgenic mice engineered to express human BDNF as