Scientists have identified a gene that appears to play a role in regulating how much alcohol people drink and say their finding could help the search for more effective treatments for alcoholism and binge drinking.
In a study of more than 47,000 people, an international team of scientists found that people who have a rarer version of a gene called AUTS2 drink on average 5 per cent less alcohol than people with the more common version.
The AUTS2 gene, also known as called "autism susceptibility candidate 2" has previously been linked to autism and attention deficit hyperactivity disorder (ADHD), but its actual function is not clear, the researchers said.
"Of course there are a lot of factors that affect how much alcohol a person drinks, but we know...that genes play an important role," said Paul Elliott of Imperial College London, who was part of the team conducting the study.
"The difference this particular gene makes is only small, but by finding it we've opened up a new area of research."
According to the World Health Organization, harmful use of alcohol results in 2.5 million deaths a year globally.
It is the world's third largest risk factor for causing diseases such as neuropsychiatric disorders (including alcoholism and epilepsy), as well as cardiovascular disease, cirrhosis of the liver and various forms of cancer.
Gunter Schumann from the Institute of Psychiatry at King's College London said combining genetic studies and behavioural data should help scientists better understand the biological basis of why people drink, some of them to excess.
"This is an important first step toward the development of individually targeted prevention and treatments for alcohol abuse and addiction," he said.
In their study, published in the Proceedings of the National Academy of Sciences (PNAS) journal, the team analyzed DNA samples from over 26,000 volunteers to search for genes that appeared to affect alcohol consumption, and then checked their findings in another 21,000 people. The volunteers answered questionnaires to report how much alcohol they drank.
After identifying AUTS2, the scientists analysed how active the gene was in samples of donated brain tissue. They found that people with the version of the gene linked to lower alcohol consumption had higher activity of the gene.
The researchers also looked at strains of mice that had been selectively bred according to how much alcohol they drink voluntarily, and found there were differences in the AUTS2 gene activity levels among different breeds.
In another part of the study using flies, the researchers found that blocking the effect of a fruit fly version of the same gene made the flies less sensitive to alcohol. This suggests AUTS2 seems to be involved in regulation of alcohol intake in a number of different species, they said.