Most studies report that BDNF genotype is not related to the risk of developing AD (Combarros et al., 2004; Nishimura et al., 2004; Li et al., 2005) [but see for evidences of effects present only in women (Fukumoto et al., 2010)], and Genome Wide Association Studies could not find a relationship between BDNF Val66Met polymorphism and risk of AD (Lambert et al., 2013). This evidence concerns the gene BDNF and Alzheimer disease.