We analyzed 359 candidate genes previously nominated as candidate genes for nicotine dependence [50], or identified in GWAS studies of dichotomized nicotine dependence and CPD [45], [59] and gene-level results are summarized in Table 3. Of note, rs3027409 in the MAOA candidate gene region had a p-value of 6.7×10−6 for association with CPDBI, which led to a gene-level p-value smaller than 5.4×10−5, the smallest a priori candidate gene association we observed. Nine candidate gene groups were associated with at least one smoking behavior at the 0.10 level (Table 4) with two (Nicotinic Receptors and Voltage-Dependent Calcium-Activated Potassium Channels) associated with a smoking behavior (CPD) at the 0.01 level.
