We hypothesized that variants within and flanking the CHRNA5-CHRNA3-CHRNB4 gene cluster on chromosome 15q24–25.1 region that were associated with nicotine dependence and smoking related phenotypes may also affect AAO of daily/habitual smoking. We tested 10 SNPs (single nucleotide polymorphisms; Table 2) in this gene cluster that tagged variants associated with nicotine dependence and smoking related phenotypes [9], [10]. Genotyping was performed at the Genome Technology Access Center at Washington University School of Medicine in St. Louis (http://gtac.wustl.edu/) using an Illumina GoldenGate custom array as part of a larger set of 384 SNPs.
