Researchers, led by scientists at Imperial College London and King’s College London have identified a gene that is linked to regulating alcohol consumption. The same gene, Autism susceptibility candidate 2, or AUTS2 has previously been linked to autism and attention deficit hyperactivity disorder.
The study included 12 population-based samples of European ancestry and included nearly 48,000 individuals. Findings suggest that there are two versions of the AUTS2 gene, one three times more common than the other. People with the less common version drink on average 5% less alcohol than people with the more common version. The gene is most active in parts of the brain associated with neuropsychological reward mechanisms, suggesting that it might play a part in regulating the positive reinforcement that people feel when they drink alcohol.
The researchers analysed 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. Volunteers reported alcohol consumption levels by questionnaire.
Once the researchers had identified AUTS2, they examined how much messenger RNA - a copy of the gene’s code that is used to make a protein - was present in samples of donated human brain tissue. They found that the people with the version of the gene associated with lower alcohol consumption produced more of the messenger RNA, meaning that the gene was more active.
The researchers also investigated strains of mice that had been selectively bred according to how much alcohol they drink voluntarily. They saw differences in the AUTS2 gene activity levels among different breeds of mice that drink more or less alcohol. The researchers also suggest that blocking the effect of a related gene in fruit flies made the flies less sensitive to alcohol. These results indicate that AUTS2 seems to be involved in regulation of alcohol intake in a number of different species.
Researchers state, “In this study we combine genetic studies with investigations of animal behaviour. Since people drink alcohol for very different reasons, understanding the particular behaviour influenced by the gene identified helps us better understand the biological basis of these reasons. This is an important first step towards the development of individually targeted prevention and treatments for alcohol abuse and addiction.”
Source: G. Schumann et al. Genome-wide association and genetic functional studies identify autism susceptibility candidate 2 gene (AUTS2) in the regulation of alcohol consumption. Proceedings of the National Academy of Sciences, 2011