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Brief Description:

Prenatal exposure to smoking combined with genes, increases teens' risk for disruptive behavior problems.

Transcript:

Akinso: A National Institute on Drug Abuse study shows that prenatal exposure to smoking combined with a specific genetic variant places teens at greatest risk for behavioral problems. To the surprise of researchers, the genetic variant that confers this increased risk differs between boys and girls. When comparing the differences between the effects that prenatal exposure to smoking has on teenage boys and girls, researchers found a difference in phenotypes, which is any observable characteristic or trait of an organism. Dr. Nora Volkow is the Director of NIDA and she examines the differences between teenage boys and girls in this study.

Volkow: What they found was actually fascinating because they did find their prediction that in males, those males who’s mothers smoked during pregnancy and who have the gene variant that led to lower concentrations were the ones that have the more aggressive phenotypes. So these were the ones who were with conduct disorders was much more prevalent. On the other hand to the surprise of everybody, females it was the opposite. The interaction that increased the risk was when the newborn was a female and had the mother had smoked the increase risk for the conduct disorder occur with they genotype that coded for the high expression monoamine oxidase gene.

Akinso: A team of researchers led by the Institute for Juvenile Research at the University of Illinois at Chicago identified a long-lasting influence on behavior of the monoamine oxidase A gene variant following tobacco exposure before birth. Monoamine oxidase A is an enzyme which regulates chemical messengers in the brain. Dr. Volkow says these findings illuminate how the interaction between genes and the environment can mold behavioral patterns very early in development.

Volkow: This study is giving more evidence about the deleterious effects of smoking during pregnancy which is unfortunate still much more prevalent that we would want it to be. It is estimated that approximately 16 percent of women still smoke during pregnancy despite the fact there’s increasing evidence that smoking during pregnancy is deleterious to the newborn.

Akinso: Dr. Volkow says these findings provide researchers with clues to the possible mechanism by which prenatal exposure may exert its effects on the brain and behavior. For more information on these findings or other NIDA research visit www.drugabuse.gov. This is Wally Akinso at the National Institutes of Health, Bethesda, Maryland.