Association between Val66Met polymorphism of Brain-Derived Neurotrophic Factor (BDNF) gene and a deficiency of colour vision in alcohol-dependent male patients

► Up to half of male heavy drinkers were found to have colour vision deficits (CVD). ► A specific genetic variation seems to offer a degree of protection against the CVD. ► We have identified this variation as a particular form of SNP in BDNF gene. ► The variation is known to be associated with higher levels the BDNF gene product. ► Mechanism may involve NMDA receptors at the cells processing colour vision in the retina.