London: Researchers have discovered a genetic mutation that could trigger violent anger under alcohol`s influence.
They sequenced the DNA of a number of impulsive volunteers and compared those sequences with DNA from an equal number of non-impulsive people.
They found that a single DNA change that blocks a gene known as HTR2B was predictive of highly impulsive behaviour. The gene affects serotonin production and detection in the brain, the Journal Nature reports.
Serotonin is a neurotransmitter known to influence many behaviours, including impulsivity, according to a leading newspaper.
"Interestingly, we found that the genetic variant alone was insufficient to cause people to act in such ways," said David Goldman at National Institute on Alcohol Abuse and Alcoholism in Maryland, US.
"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 behavioural disinhibition."
In collaboration with researchers in Finland and France, Goldman and his colleagues studied a sample of violent criminal offenders in Finland.
The hallmark of the violent crimes committed by individuals in the study sample was that they were spontaneous and purposeless.
They found the association with HTR2B gene and then conducted studies in mice and found that when the equivalent gene is knocked out or turned off, mice also become more impulsive.
"Impulsivity, or action without foresight, is a factor in many pathological behaviours including suicide, aggression, and addiction," said Goldman.