Scientists studying the DNA marker profiles between smokers and non-smokers have found several genetic variants that are associated with key smoking behaviors.

In a new Nature Genetics paper, the international research team reported that three genetic regions are associated with the number of cigarettes smoked per day, one with smoking initiation and one with smoking cessation.

The variants on chromosome 15 associated with heavy smoking lie within a region that contains nicotinic receptor genes, which other scientists have previously associated with nicotine dependence and lung cancer.

Researchers used data from genome-wide association studies to establish the genetic links to smoking. Genome-wide association studies (GWAS) search for genetic variants involved in a disease which may ultimately help prevent, diagnose, and treat the disease. Because smoking behavior is associated with many diseases, such as heart disease and cancer, the researchers were able to assemble more data to test the links between genetic variants and smoking than any one study could provide alone.

“We hope that this work will allow researchers from multiple disciplines to develop a better understanding of the genetics of addiction and evaluate how drug-gene interactions could be used to create and tailor therapies to improve the rates of smoking cessation,” said Helena Furberg, Department of Genetics, University of North Carolina, Chapel Hill.

“More work needs to be done before these findings can be used to treat smokers who wish to quit. At this time, testing for these variants will not tell you anything meaningful about your risk of smoking or nicotine dependence. Of course, all smokers should be encouraged to quit regardless of their genetic make-up,” she added.

Citation: The Tobacco and Genetics Consortium, 'Genome-wide meta-analyses identify multiple loci associated with smoking behavior', Nature Genetics, April 2010; doi:10.1038/ng.571