Study Points to Genetic Variant in Violent Criminals
New research from the Karolinska Institute in Sweden suggests there may be a link between variants in two genes and violent tendencies. The researchers found the gene variants were significantly more common in Finnish criminals convicted of repeated violent crimes when compared to those in the general population.
However, don’t think the gene variant excuses violent crimes. Jari Tiihonen, MD, PhD, and colleagues said statistical analysis indicates that only 5% to 10% of all severe violent crime in Finland could potentially be attributed to these gene variants.
The variants affect the genes for monoamine oxidase A (MAOA) and CDH13, a neuronal membrane adhesion molecule.
The findings showed that those who had committed 10 or more serious violent crimes were significantly more likely to carry one of the variants compared to individuals in population-based survey studies in Finland who were considered representative of the general population.
The researchers also found that criminal offenders with no history of violent crime convictions showed no increased risk of carrying the variants compared to the population-based sample. Neither populations showed a statistically significant rate of the variants.
In the report published in Molecular Psychiatry, the team noted that crime “is a complex phenomenon, and the outcome is shaped by both genetic and environmental factors.” However, they argue that does not negate the importance of identifying genetic contributors. They argue, “It is plausible that while research of the genetic background of criminal or violent behavior is hampered by many confounding factors, focusing on extreme phenotypes might yield more robust results.”
“This was demonstrated in our analysis on the association between rs11649622 [variant in the CDH13 gene] and MAOA genotypes versus the number of committed violent crimes, showing clear dose-response effects.”
While these findings are interesting, the presence of the MAOA or CDH13 variants are too limited to provide practical applications at the time, but they open the possibility of further research which could potentially change how we view crime in the future.n