BDNF and atypical Rett syndrome: Some epidemiological studies have also found that BDNF Met66 allele carriers are relatively less prone to epilepsy in patients with Rett syndrome (Nectoux et al., 2008), suggesting that altering the molecular structure of BDNF may have an inhibitory effect on epilepsy formation and BDNF may have an important role in promoting epilepsy formation.