We reviewed the literature and identified several GWAS investigating smoking behavior, as assessed by CPD, as an outcome (6-10,12,13). Overall 10 single nucleotide polymorphisms (SNPs) from 5 loci which were found to be genome-wide significant for CPD: 7p14, 8p11, 10q23, 15q25 and 19q13 were selected for genotyping (Table 2). Genotyping was performed using the 5′ exonuclease assay (TaqMan) at IARC. PCR primers and TaqMan probes were synthesized by Applied Biosystems (Foster City, CA, U.S.A.). Highly correlated proxies (r2=1.0) were genotyped in place of assays that were unable to be designed as TaqMan assays. Only one SNP of any correlated group of variants (r2>0.5) was genotyped.
