Figure 1
SNP and indel associations with nicotine dependence from meta-analyses of discovery and independent replication samples, all of European-ancestry. The −log10 (meta-analysis P) results are plotted by chromosomal position: (a) genome-wide meta-analysis results across the five discovery samples (total N=17 074) for 9.9 million genotyped and imputed SNPs and indels tested for association with nicotine dependence (SNPs shown as circles and indels shown as triangles) with minor allele frequency >0.01 and (b) regional meta-analysis results across all 10 discovery and replication samples (total N=24 543) in the CHRNA4 gene on chromosome 20q13. For the regional plot, the r2 values between the top SNP (rs2273500, shown in purple) and other SNPs in the flanking region were based on the 1000 Genomes European reference panel (denoted EUR); the indels are shown in gray. The solid black lines mark the genome-wide statistical significance threshold (meta-analysis P<5 × 10−8). indel, insertion/deletion; SNP, single nucleotide polymorphism.
