Ebrii gignunt ebrios--One drunkard begets another: the genetics of alcohol dependence.

Family, twin, and adoption studies provide convincing evidence of a genetic contribution to the predisposition to alcohol dependence. Two main molecular genetic approaches, namely linkage and association, have been adopted to identify the genes that underpin that genetic vulnerability. Robust findings have implicated genes involved in alcohol metabolism, particularly when studied in Asian populations. These include the genes encoding aldehyde dehydrogenase 2 and several alcohol dehydrogenases. Other findings have proven to be less resilient, but have often implicated genes of the dopaminergic, GABA-ergic and serotonergic systems. Improvements in sample collection and characterization, technological and statistical advances, combined with a developmental approach, should enable molecular genetics to deliver on its initial promise of identifying the genes involved. These findings will have important implications for the identification and targeting of treatment. However it is anticipated that this information will have little impact on risk alteration and consequently population screening will be highly unlikely. Genetic factors always should be considered in the context of their developmental interplay with those of the environment.