The HTR2B variant of a serotonin neurotransmitter receptor in the brain makes Finnish men violent if they drink. The HTR2B variant occurs at a much higher rate in violent felons.
A multinational research team led by scientists at the National Institutes of Health has found that a genetic variant of a brain receptor molecule may contribute to violently impulsive behavior when people who carry it are under the influence of alcohol. A report of the findings, which include human genetic analyses and gene knockout studies in animals, appears in the Dec. 23 issue of Nature.
"Impulsivity, or action without foresight, is a factor in many pathological behaviors including suicide, aggression, and addiction," explains senior author David Goldman, M.D., chief of the Laboratory of Neurogenetics at the NIH’s National Institute on Alcohol Abuse and Alcoholism (NIAAA). "But it is also a trait that can be of value if a quick decision must be made or in situations where risk-taking is favored."
This is an example of why it is valuable for individuals to get their genomes tested. Direct-to-consumer genetic testing ought to be available without regulatory barriers in the way (please tell the FDA and the California and NY state governments). Whether you carry a genetic variant that is liable to make you violent under the influence of alcohol is knowledge that teenagers ought to know. It could save lives, prevent maiming, and keep our prisons less crowded.
Scientists will discover all the genetic variants that make some people dangerous when drunk. I say the sooner the better.
"Interestingly, we found that the genetic variant alone was insufficient to cause people to act in such ways," notes Dr. Goldman. "Carriers of the HTR2B variant who had committed impulsive crimes were male, and all had become violent only while drunk from alcohol, which itself leads to behavioral disinhibition."
The researchers also found that knocking out this gene in mice caused the mice to become more impulsive. The researchers are currently trying to determine whether alcohol makes those mice even more impulsive. Obviously, this could lead to a genetic test to determine whether it is safe to let your pet mouse drink alcohol.
Other genetic variants that increase impulsive and violent behavior are likely to be found.
"Although relatively common in Finland, the genetic variant we identified in this study is unlikely to explain a large fraction of the overall variance in impulsive behaviors, as there are likely to be many pathways to impulsivity in its various manifestations," says Dr. Goldman.
They found that 7.46% of the violent offenders had the mutation, compared with 2.32% of controls.
|Share |||Randall Parker, 2010 December 24 11:46 PM Brain Violence|