In summary, the current study adds to the literature by supporting evidence of genetic linkage of chromosome 2q to nicotine dependence. This study extends this finding by showing that this region confers risk to the full nicotine dependence diagnosis rather than a specific facet of the disorder. Finally, the present study suggests this locus, as well as the additional loci identified, confers risk to nicotine but not alcohol dependence, thus providing evidence that this genomic region may harbor a gene specifically involved in the physiological effects and/or metabolism of nicotine.
