- Published: November 1, 2012
- Written by Joshua Jackson
Monoamine oxidase A helps break down neurotransmitters such as serotonin, dopamine, and norepinephrine. Low levels of MAO-A have been linked to violent and agressive antisocial behavior. It appears that an MAO-A deficiency leads to longer retention of tension and anxiety after an inciting event. There are common variations in the genes that code for MAO-A, and some forms lead to decreased production. An extremely rare form of this is known as Brunner syndrome which leads to a severe MAO-A deficiency. Only a handful of cases of Brunner's syndrome have been identified, but violent crime is extremely prevalent among them. Genes for less severe variations of MAO-A deficiency are much more common and a link has been suggested between them and crime. The connection is controversial as there is a significant difference in the distribution of the genes between races. If further research shows that the presence of these genes is a significant factor for predicting criminal behavior, it could be valuable in considerations of sentencing and parole.
1. Brunner et al. “X-linked borderline mental retardation with prominent behavioral disturbance: phenotype, genetic localization, and evidence for disturbed monoamine metabolism.” American Journal of Human Genetics. vol 52 pg 1032-1039