Dr. Kirk Wilhelmsen of the University of North Carolina at Chapel Hill School of Medicine says up to 20 percent of people, who react more strongly to alcohol in the first few drinks, may have the gene variant, called CYP2E1.
"We have found a gene that protects against alcoholism, and on top of that, has a very strong effect," Wilhelmsen says in a statement. "But alcoholism is a very complex disease, and there are lots of complicated reasons why people drink. This may be just one of the reasons."
Wilhelmsen, the lead author, and colleagues collected hundreds of pairs of siblings, all at college-age and all with at least one parent who was an alcoholic. The study participants were given a mixture of grain alcohol and soda that was equivalent to about three drinks that they drank at regular intervals. They were asked to answer questions describing how the alcohol made them feel: "I feel drunk, I don't feel drunk; I feel sleepy, I don't feel sleepy."
The researchers conducted genetic analyses to hone in on the gene region of CYP2E1 that appeared to influence how the students perceived alcohol.
The findings are published online ahead of print in the January issue of the journal Alcoholism: Clinical and Experimental Research.