Association of genes coding for the alpha-4, alpha-5, beta-2 and beta-3 subunits of nicotinic receptors with cigarette smoking and nicotine dependence.

We assessed whether smoking behavior was associated with nine polymorphisms in genes coding for the nicotinic receptor subunits alpha-4 (rs1044394, rs1044396, rs2236196 and rs2273504), alpha-5 (rs16969968), beta-2 (rs2072661 and rs4845378) and beta-3 (rs4953 and rs6474413).We conducted an Internet survey and collected saliva by mail for DNA and cotinine analyses, in Switzerland in 2003. We conducted DNA analyses for 277 participants and cotinine analyses for 141 current daily smokers.