U researchers have found a gene that correlates with nicotine addiction in long-term smokers who started before the age of 17.
“People who initiate smoking by age 17 are on average more heavily dependent in their lifetime smoking behavior,” said Robert Weiss, lead author of the study and U professor of human genetics. “This finding is a genetic underpinning of that effect that’s been measured in smoking populations.”
The researchers compared the variation in a range of genes for nicotine receptors in the brain with the variation in how dependent the subjects were to nicotine, and with how early the subjects began smoking. .
U researchers worked with faculty at the University of Wisconsin-Madison to study 2,827 long-term smokers of European descent. Groups of subjects were compiled in Utah and Wisconsin, and a third group is being studied in the National Lung Health Study.
Researchers found that subjects who had version A of the gene were more likely to have a higher dependency level if they started smoking during adolescence.
However, subjects with version C were less likely to have a higher dependency level under the same circumstances.
“This is really a first step,” said Glen Hanson, a U professor of pharmacology and toxicology and director of the Utah Addiction Center. “This is a door that has opened up. We now have a place to focus our research. We can devise strategies in terms of prevention and recovery.”
For example, researchers can now focus on why variations of this gene are related to smoking behavior, both on the microbiological and behavioral model.
Some of the researchers are already exploring possibilities for further research using the mouse-model technique pioneered by the U’s Nobel Laureate and human genetics researcher, Mario Capecchi, for genetic investigations.
Weiss warned that it’s not yet clear how the genetic interaction with smoking severity and age of onset will play out in other population groups.
“Among Asians and Africans, the risk variant is probably lower-perhaps around 8 percent,” he said.
Weiss said that although testing to see how likely a person could become addicted to nicotine would be fairly inexpensive, he thinks the results will be a tool for further research to use.
“No one should start smoking as an adolescent, regardless of their genes,” he said.
Thien ShokU researchers Dr. Dale Cannon, Dr. Mark Leppert and Dr. Robert Weiss have discovered a gene that is correlated with nicotine addiction.