Scientists have identified a gene that may help identify people who are more susceptible to alcohol abuse later in life.
Dr Raymond White, who led the team at the Ernest Gallo Clinic and Research Center in California, looked at how strongly people were affected by drinking in terms of body sway, co-ordination problems and feeling "high", and pinpointed the stretch of DNA that appeared to determine it.
The researchers found that people who show little response to alcohol have a higher likelihood of alcohol dependence and abuse and this is influenced by genetics.
Drinkers who show a low level of response to alcohol can consume more before feeling the effects of intoxication and are more likely to succumb to alcoholism.
The researchers said the findings confirmed that tolerance, dependence and abuse were "influenced by a genetic component".
The scientists based their research on 313 students and analysed the link between areas of DNA and three factors that measures the response to alcohol.
In an "alcohol challenge", the 18-to-29-year-olds drank a 20 per cent by volume solution of ethanol in an eight-minute period.
The subjects then completed a form to indicate how intoxicated they felt at various intervals after the drink. Body sway was also measured using a special harness.
The researchers found a strong association between a specific part of the drinker's genes and the swaying of their body. They found that a single sequence on chromosome 15 was significantly linked to the level of alcohol response.
While other studies have connected chromosome 15 with alcoholism, the authors propose that the specific sequence CHRNA5 was most likely to cause the individual variation in alcohol response.
The study could also lead to a genetic test that could reveal tolerance and susceptibility to alcohol abuse.
"The findings reported here, combined with the recently published findings of association of the chromosome 15 locus with alcohol dependence, provide further evidence that alcohol low response is a hereditary characteristic of alcohol use disorders," the Telegraph quoted White, as saying.
The study is published in the Proceedings of the National Academy of Sciences.