We now understand the chain of action: how our genes shape this function in our brains and how that, in turn, leads to human behaviour.We found that the RASGRF-2 gene plays a crucial role in controlling how alcohol stimulates the brain to release dopamine, and hence trigger the feeling of reward. So, if people have a genetic variation of the RASGRF-2 gene, alcohol gives them a stronger sense of reward, making them more likely to be heavy drinkers. (source)
And the BBC article continues:
He said more work was needed to prove this theory - the study only looked at young teenage boys, making it difficult to assess a link with long-term drinking patterns.
It is a preliminary association (ie the study design was not explicit for the finding they made), though the functional work (animal model) looks promising.
In my own family history there is strong evidence of alcoholism, and binge drinking as well. Findings like these make me want to have my genome sequenced. But other reasons, money being a prohibiting factor anyway, keep me from doing so. Its just cool when we can combine this kind of information to understand our genes.