Genetic tests using blood samples already are used to diagnose some diseases and even personalize treatment.

Now it is possible to develop similar tests that reveal a person's potential to become dependent on nicotine or marijuana or have antisocial personality disorder, University of Iowa researchers report online March 6 in the American Journal of Medical Genetics.

Such tests would not dictate who would become substance dependent or have behavioral problems, as genes do not function in isolation but are influenced by other genes and environmental factors, said the study's lead author Robert Philibert, M.D., Ph.D., professor of psychiatry in the UI Roy J. and Lucille A. Carver College of Medicine.

"Our study suggests that analyzing the expression of genes in blood could indicate whether a person is susceptible to having a behavioral disorder. Having a particular gene expression change does not by itself predict that a person will act a certain way. However, it can indicate who might have a greater biological basis for engaging in behaviors such as smoking and alcohol or marijuana use," Philibert said.

"What matters most is not whether you have a particular gene but whether the gene is expressed, and what other environmental factors may be at play. Genetic variation in and of itself is not deterministic," he added.

In a related study also published online March 6, Philibert and colleagues reported a potential blood test for panic disorder. Both the panic disorder study and one on substance abuse used data from the Iowa Adoption Studies, which were established by Remi Cadoret, M.D., an internationally renowned UI professor of psychiatry who passed away in 2005.

In this latest study, the researchers found certain differences in the genes of people with a history of smoking compared to those without such a history. In all, 579 genes were more expressed and 584 genes were less expressed in people who had
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Contact: Becky Soglin
becky-soglin@uiowa.edu
319-335-6660
University of Iowa
6-Mar-2007