Unhealthy environment tunes kids' genes for anti-social behaviour

Toronto: Exposure to family conflict or sexual abuse could affect expression of certain genes and make your kids prone to delinquent behaviour, a new research has found. Both positive and negative experiences influence how genetic variants affect the brain and thereby behaviour, the findings showed.

Thus, the same genetic variants were associated with high and low levels of juvenile delinquency depending on exposure to negative or positive environments. "We found that three genetic variants interacted with each other, with family conflict and sexual abuse to increase the likelihood of delinquency, and positive parent-child relationship to decrease the risk of delinquency," said Sheilagh Hodgins from the University of Montreal in Canada.

The study involved 1,337 high school student aged 17 to 18 years in Sweden. They anonymously completed questionnaires reporting on delinquency, family conflict, experiences of sexual abuse, and the quality of their relationship with their parents. They also provided a sample of saliva from which the researchers extracted DNA and studied three gene variants - Monoamine oxidase A (MAOA) gene, brain derived neurotrophic factor (BDNF) gene and serotonin transporter 5-HTTLPR gene.

"Among carriers of the low activity variants of all three genes, those exposed to family conflict or sexual abuse or both reported high levels of delinquency while those who reported a positive and warm relationship with their parents reported little or no delinquency," Hodgins added.