Researchers at the University of North Carolina have found a version of a gene that may make certain people more sensitive to alcohol.

The variant occurs in the gene CYP2E1, which is associated with response to alcohol. Researchers estimate that 10-20% of people have this gene variant, causing them to become inebriated more quickly than those who do not have the variant.

The study looked at over 200 pairs of college-age siblings with at least one parent who was an alcoholic. The participants were given a mixture of grain alcohol and soda equivalent to three standard drinks, and then asked to describe how the alcohol made them feel.

Enzymes in the liver break down most of the alcohol consumed, while some of it is metabolised in the brain. This is done by an enzyme that is coded for by the CYP2E1 gene. The study suggests that the conventional model of how alcohol affects neurotransmitters is too simplistic; the perceptions of impairment are more complex than accounted for.

“Sequence changes in or near CYP2E1 affect the level of response to alcohol, providing a predictor of risk of alcoholism”, the study concluded.

Previous research has indicated that people who react strongly to alcohol are less likely to become alcoholics than those who feel a weaker response in their early drinking experience. The present study provides a genetic basis for these previous findings. The study allows inferences to be made about how the brain perceives alcohol, contributing to the growing understanding of alcoholism.