Genes, violence and learning disabilities

Between fifteen and twenty per cent of people with learning disabilities have behaviour problems. Researchers from Vanderbilt University in Tennesee have been looking at how genetics might play a part in this. They looked at a gene linked to a substance called monoamine oxidize A (MAOA) which in turn regulates the neurotransmitters serotonin (linked to appetite and mood) and norepinephrine (linked to the 'fight-or-flight' response). Previous studies have linked a variation in this gene to violent behaviour. The researchers studied 105 men between the ages of 18 and 50. Some had learning disabilities and a history of violent behaviour, others had learning disabilities but no history of violent behaviour while the remainder formed a control group of men with no learning disabilities and no history of violence. The researchers found that 43% of those with learning disabilities and a violent past had the gene variation compared to only 20% of the other two groups.

You can find out more about this research at

http://www.sciencedaily.com/releases/2009/07/090721122855.htm