Nicotine addiction linked to gene variations

According to researchers at the University of Utah and University of Wisconsin-Madison in the United States, common genetic variations affecting nicotine receptors in the nervous system can significantly increase the chance that European Americans, who begin smoking by age 17, will struggle with lifelong nicotine addiction.  

"This finding suggests that genetic influences expressed during adolescence contribute to the risk of lifetime addiction severity produced from the early onset of tobacco use," Professor Robert Weiss, the lead author of the study, was quoted as saying by the Science Daily online.  

 

These common gene variations, called single nucleotide polymorphisms (SNPs), are changes in a single unit of DNA. Scientists call SNPs that are linked and inherited together a haplotype, the report said.  

The high-risk haplotype is common in the three study populations, and European American populations in general, ranging in frequency from 38 per cent to 41 per cent.  

The researchers studied 2,827 long-term European American smokers, recruited in Utah and Wisconsin, and to the National Heart, Lung, and Blood Institute's Lung Health Study.  

The findings showed that one haplotype for the nicotine receptor put European American smokers at greater risk of heavy nicotine dependence as adults, if they began smoking before the age of 17.