May 22, 2012 -- A "smoking gun" gene may play a role in how many cigarettes certain smokers puff each day.
Researchers from 50 medical institutions across the country analyzed genetic material of more than 32,000 African-American smokers and non-smokers to see if certain genes predicted when they began smoking, how many cigarettes they smoked, and how easily they were able to quit.
According to the new study, a variant in a nicotine receptor gene predicts about one extra cigarette smoked per day. This same general location has been implicated in smoking behavior among white Europeans. Among African-Americans, the new genetic marker appears on a different spot on the same gene.
The findings appear in the May 22 issue of Translational Psychiatry. They are part of the Study of Tobacco in Minority Populations (STOMP) Genetics Consortium.
"This region is really important for addiction biology, regardless of race or ethnicity," says researcher Helena Furberg, PhD, an assistant attending epidemiologist at Memorial Sloan-Kettering Cancer Center in New York City.
This is somewhat surprising, she says. "Smoking behaviors differ among ethnic groups." For example, African-Americans typically start smoking at later ages than their counterparts of European descent and smoke fewer cigarettes each day. But they have a higher risk for lung cancer and are less likely to quit smoking.
The findings hold potential for tailoring smoking cessation treatments down the road, Furberg says. "The next research step would be to see if currently available smoking cessationmedications would work better or differently among people who carry these variants."
Sean David, MD, is a clinical associate professor of medicine at the Stanford University School of Medicine in Stanford, Calif., and the lead researcher of the study. "Genes account for about 50% of differences between individuals in terms of risk for nicotine dependence and how many cigarettes they smoke per day," he says. This means environmental factors are equally important.
The new indicator predicts about one extra cigarette smoked per day.
David, director of the Translational Medicine Program at SRI International, hopes that these findings pave the way toward better smoking cessation treatments and prevention of lung cancer and other smoking-related diseases.