Single nucleotide polymorphisms (SNPs) associated with the lifetime average number of cigarettes smoked per day (CPD) (log2-transformed) with meta-analytic p<10−5, and candidate SNPs from CHRNA3/CHRNA5 and CYP2A6 loci identified by previous studies
| Chr. | Top SNP | Nearest gene within 50 kb (location) | Effect/non-effect allele | B | p | I2 | Q stat. | N/Nimp | Freq. | Effect direction consistent with previous studies | |
| Top SNPs | 4 | rs13104971 | SCFD2 (intron) | G/A | 0.113 | 1.18×10−6 | 0 | 0.92 | 4/3 | 0.13 | – |
| 9 | rs943306 | ASTN2 (intron) | T/C | 0.073 | 1.25×10−6 | 25 | 0.26 | 4/0 | 0.40 | – | |
| 7 | rs10237067 | – | A/G | 0.072 | 2.98×10−6 | 0 | 0.63 | 4/3 | 0.63 | – | |
| 7 | rs12699125 | CALN1 (intron) | A/G | 0.072 | 3.17×10−6 | 42 | 0.16 | 4/3 | 0.66 | – | |
| 7 | rs4718827 | – | T/C | 0.072 | 3.36×10−6 | 0 | 0.61 | 4/4 | 0.63 | – | |
| 7 | rs4717631 | CALN1 (intron) | A/G | 0.072 | 3.60×10−6 | 43 | 0.15 | 4/4 | 0.66 | – | |
| 7 | rs17170849 | ELMO1 (intron) | C/T | 0.265 | 4.07×10−6 | 44 | 0.15 | 4/3 | 0.02 | – | |
| 7 | rs4577845 | CALN1 (intron) | G/A | 0.071 | 4.57×10−6 | 44 | 0.15 | 4/1 | 0.66 | – | |
| 7 | rs1859485 | CALN1 (intron) | T/C | 0.069 | 6.95×10−6 | 40 | 0.17 | 4/1 | 0.65 | – | |
| 12 | rs11044734 | – | G/C | 0.112 | 7.32×10−6 | 0 | 0.48 | 4/4 | 0.90 | – | |
| 12 | rs11044737 | – | G/A | 0.112 | 7.70×10−6 | 0 | 0.47 | 4/0 | 0.90 | – | |
| 16 | rs190369 | – | C/T | 0.161 | 8.89×10−6 | 47 | 0.13 | 4/1 | 0.05 | – | |
| 20 | rs2869961 | CEBPB (5′ region) | A/G | 0.104 | 9.65×10−6 | 0 | 0.59 | 4/1 | 0.12 | – | |
| Candidate SNPs | 15 | rs1051730 | CHRNA3 (exon, Tyr215Tyr) | A/G | 0.060 | 0.00011 | 37 | 0.19 | 4/0 | 0.41 | Yes |
| 15 | rs16969968 | CHRNA5 (exon, Asp398Asn) | A/G | 0.059 | 0.00015 | 30 | 0.23 | 4/3 | 0.41 | Yes | |
| 15 | rs8034191 | AGPHD1 (intron) | C/T | 0.055 | 0.00036 | 40 | 0.17 | 4/0 | 0.41 | Yes | |
| 15 | rs684513 | CHRNA5 (intron) | C/G | 0.029 | 0.163 | 0 | 0.98 | 4/4 | 0.80 | Yes | |
| 15 | rs578776 | CHRNA3 (3′ UTR) | G/A | 0.041 | 0.020 | 0 | 0.94 | 4/0 | 0.76 | Yes | |
| 15 | rs588765 | CHRNA5 (intron) | C/T | 0.031 | 0.046 | 47 | 0.13 | 4/4 | 0.60 | Yes | |
| 19 | rs3733829 | EGLN2 (intron) | G/A | 0.019 | 0.223 | 0 | 0.48 | 4/3 | 0.39 | Yes | |
| 19 | rs7937 | RAB4B (3′ UTR) | T/C | 0.022 | 0.153 | 0 | 0.96 | 4/0 | 0.60 | Yes | |
| 19 | rs1801272 | CYP2A6 (exon, Leu160His) | A/T | 0.266 | 2.78×10−5 | 0 | 0.72 | 4/4 | 0.96 | Yes | |
| 19 | rs4105144 | CYP2A6 (5′ region) | C/T | 0.073 | 3.92×10−5 | 0 | 0.44 | 4/4 | 0.73 | Yes | |
| 19 | rs7260329 | CYP2B6 (intron) | G/A | 0.014 | 0.404 | 0 | 0.55 | 4/1 | 0.68 | Yes | |
| 19 | rs7251570 | CYP2A6 (3′ region) | G/A | 0.057 | 0.00073 | 0 | 0.84 | 4/4 | 0.71 | Yes | |
| 19 | rs12461383 | CYP2A7 (3′ region) | G/C | 0.063 | 0.00019 | 0 | 0.61 | 4/4 | 0.60 | Yes |
Analyses were adjusted for sex, age and principal components for genetic ancestry.
P values < 0.05 are depicted in bold. N/Nimp, number of studies contributing to the meta-analysis/number of studies in which SNP was imputed; I2, heterogeneity index; Q stat., p value for Q statistic; p, p value from the fixed effect meta-analysis; Freq., effect allele frequency in 3441 patients with at least one non-missing phenotype from four cohorts studied; Chr., chromosome; B, regression coefficient; UTR, untranslated region; CHRNA3/CHRNA5, cholinergic receptors, nicotinic, alpha 3/5; CYP2A6, cytochrome P450, family 2, subfamily A, polypeptide 6.