13:06 23 December 2010 by Andy Coghlan
" A gene mutation linked with impulsivity and possible violent outbursts has been discovered in Finnish men convicted of violence and arson.
The mutation, in a gene called HTR2B, prevents production of the serotonin 2B receptor, a key docking point in brain cells for the neurotransmitter serotonin. One consequence could be depletion of serotonin in the nucleus accumbens, a part of the brain involved in providing restraint and foresight into the consequences of actions.
The mutation was three times as common in violent criminals as in the general population. Of 228 Finnish inmates serving sentences for violent crimes who were screened, 17 carried the mutation, compared with only 7 of 295 healthy controls.
Although the mutation appears confined to Finnish people, it could have counterparts in populations elsewhere, with similar negative consequences, say the researchers.
"We would anticipate that over time, a large number of functional variants [of HTR2B] will be identified, with a range of behavioural effects," says David Goldman at the US National Institute on Alcohol Abuse and Alcoholism in Bethesda, Maryland, and head of the team that carried out the work.
Impulsivity played a pivotal role in the criminal behaviour of all 17 prisoners carrying the mutation, who were convicted of crimes ranging from murder and attempted murder to arson, battery and assault. "The crimes occurred as disproportionate reactions to minor irritations and were unpremeditated, without potential for financial gain and recurrent," say the researchers in Nature. . . " Read More