Scientists from deCODE genetics have identified a clear link between one genetic variant and susceptibility to nicotine dependence and will publish their results in the April 3 issue of Nature. Moreover, in part because of its impact on smoking behavior, each copy of the risk variant of this SNP confers an approximately 30% increase in risk of lung cancer and a 20% increase in risk of peripheral arterial disease (PAD), a common and debilitating constriction of the arteries to the legs.

deCODE scientists came upon the genetic variant by closely examining the genetic makeup of more than 10,000 smokers. They then followed up with an analysis of 32,000 patients and controls from Iceland, New Zealand, Austria, Sweden, Italy, the Netherlands and Spain for lung cancer and PAD, two common diseases strongly associated with smoking.

Kari Stefansson, deCODE CEO, expressed the importance of the discovery: “These findings provide an example of the power of human genetics for shedding light on the most complex health challenges. Not only have we made a convincing link between a single genetic variant and a behavioral disorder – greater smoking quantity and addiction to nicotine – but also demonstrated how this risk factor translates into risk of lung cancer and PAD.”

Stefansson also pointed out that deCODE’s genetic profile service, deCODEme, will test for the gene immediately.

Details of the smoking gene study, which was funded in part by the European Commission, and from the National Institute of Drug Abuse of the U.S. National Institutes of Health, are available at www.nature.com.