A DNMT3B gene variant is commonly found in people of European and African descent. This variant increases the likelihood of developing nicotine dependence, heavy smoking, and the risk of developing lung cancer, says study led by RTI International.
Nearly 1 billion people smoke and 6 million premature deaths occur worldwide each year from cigarette smoking, according to the World Health Organization. Smoking is the leading cause of preventable death and one person dies approximately every 6 seconds from smoking-related causes, according to the WHO.
The new study, published in Molecular Psychiatry, is the largest genome-wide association study of nicotine dependence. Researchers studied more than 38,600 former and current smokers from the United States, Iceland, Finland, and the Netherlands.
The genetic variant was linked to an increased risk of nicotine dependence by testing nearly 18 million variants across the genome for association with nicotine dependence. The variant was also tested in independent studies and found to associate with heavier smoking and with increased risk of lung cancer.