adjusted p value < .05). The lack of consistency between Australian and Finnish samples may also be due to the greater genetic homogeneity of a Finnish sample relative to other Caucasian samples (Peltonen et al., 2000). On 11q, the combined linkage peak of LOD =2.30 resulted from 199 families with 300 sib-pairs, and while the peak is smaller in magnitude, it may eventually prove to be a true signal. Thus, these findings will need to be extended and replicated using other samples. The examination of possible sex differences associated with these effects should be pursued in future work, with larger sample sizes, using SNPs within specific genes of interest. This linkage panel set includes markers at approximately every 10 cM. Thus, fine-mapping of this region will be necessary to narrow this linkage region. Despite limitations, these findings contribute to the growing evidence that chromosome 11 may harbor genes associated with smoking behavior (Li, 2008), and highlights the potential value of focusing specifically on nicotine withdrawal as one important aspect of smoking behavior that is partly under genetic influence.
