Figure 3.

There was a chromosome 12 signal associated with the Nicotine Metabolite Ratio in African American females which was not significant in African American males. The nicotine metabolite ratio was rank-transformed for analysis. A regional plot, generated using LocusZoom⁴⁴ (freely available at locuszoom.org), shows the top overall chromosome 12 variant (rs12425845) in AA females (a); the influence of rs12425845 on the Nicotine Metabolite Ratio (NMR) in AA females is shown in (b). The chromosome 12 locus containing rs12425845 was not significant in AA males (c); the lack of influence of rs12425845 on the NMR in AA males is shown in (d). Linkage disequilibrium patterns in (a) and (c) are based upon the hg19/1000 Genomes November 2014 release African reference population. The plots in (b) and (d) were created using SPSS version 23 (can be purchased from IBM, Armonk, New York, USA). The black horizontal line represents the mean rank-transformed NMR in each group, and the P-value is from the GWAS after adjusting for population substructure and NMR covariates.