We present herein results from a GWAS study of the ordinal trait, FTND score. Our results differ substantially from those of most other studies of nicotine-related traits. In many prior studies, an association peak was observed over the chromosome 15 nicotinic receptor cluster that was much larger than other association peaks. We also found little overlap with risk genes identified from our previous GWAS of cocaine, opioid, and alcohol dependence (1–3), the one exception being DISC1, discussed below. Some risk genes that we identified appear to be of biological relevance. More GWS results were identified in the AA than the EA part of the sample, which is similar to what we observed for the SD traits studied in this sample previously.
