Genetic Variant Linked To Nicotine Addiction, Lung Cancer

Scientists have identified a genetic variant that not only makes smokers more susceptible to nicotine addiction but also increases their risk of developing two smoking-related diseases, lung cancer and peripheral arterial disease. The research was supported by the National Institute on Drug Abuse (NIDA), part of the National Institutes of Health (NIH).

The study, published in the April 3 issue of the journal Nature, "highlights the advances that are being made in genetics research, which can now identify gene variants that increase the risk of complex bio-behavioral disorders," says NIH Director Dr. Elias Zerhouni. "This finding will help us in our efforts to further reduce the scope and devastating consequences of cigarette smoking."

"These results suggest for the first time that a single genetic variant not only can predispose to nicotine addiction but may also increase sensitivity to extremely serious smoking-related diseases," explains NIDA Director Dr. Nora Volkow. "Additionally, it points to potential targets for new smoking-cessation medications that may be more effective at helping smokers to quit."

The variant is closely linked to two of the known subunits of nicotine receptors, the sites on the surface of many cells in the brain and body that can be bound by nicotine. When nicotine attaches to these receptors in the brain, there are changes in cell activity that results in its addictive effects.

Carriers of this genetic variant are more likely than noncarriers to be heavy smokers, dependent on nicotine, and less likely to quit smoking. "The variant does not increase the likelihood that a person will start smoking, but for people who do smoke it increases the likelihood of addiction," says Dr. K