Haplotypes of four novel single nucleotide polymorphisms in the nicotinic acetylcholine receptor beta 2-subunit (CHRNB2) gene show no association with smoking initiation or nicotine dependence

Several types of evidence, including experiments with mice that lack the ni cotinic acetylcholine receptor beta 2-subunit gene (CHRNB2), have suggested that a beta 2-containing nicotinic receptor is necessary for at least some of the reinforcing properties of nicotine, However, sequence variations in CHRNB2 have not been reported, and its role in influencing human smoking b ehavior and nicotine dependence is not known. We screened most of the intro ns and exons and found five novel single nucleotide polymorphisms (SNPs), W e tested four of these SNPs in three large, carefully selected samples: non smokers (n = 317) and regular smokers low levels of nicotine dependence (ND , n = 238), or smokers with high-ND (n = 317), None of the four polymorphis ms we tested, nor their estimated haplotypes, were associated with smoking initiation or progression to nicotine dependence. Am. J. Med.Genet. (Neurop sychiatr. Genet.) 96:646-653, 2000, (C) 2000 Wiley-Liss, Inc.