trait linked to chr6q26. The multipoint P and the empirical P suggest that a linkage analysis result of this magnitude is expected by chance approximately 5% of the time in this sample (44). Existing linkage studies using nicotine withdrawal symptoms include only the studies of Swan et al., and a linkage study in two European ancestry populations that identified a genome-wide significant linkage on chr11p15 in the region of several monamine and nicotinic acetylcholine candidate genes, as well as two other regions of interest on chromosomes 6p and 11q (45). Other linkage analyses have identified suggestive linkage evidence (44) for smoking related behaviors on chr6q. Evidence of suggestive linkage was found for a combined dependence phenotype for any drug class and / or regular tobacco usage (every day for at least 1 month), analyzed as a threshold or continuous trait (LOD=2.54 or LOD=3.3) in a linkage sample of 49 pedigrees at 157 cM on chr6q25.3 (46), using the same linkage scan panel as used in this analysis. Analysis of a combined trait of BMI, drug dependence and / or regular tobacco use in the same sample reached a MLS of 4.1 at 151 cM on chr6q25.2. A search of the
