Previous linkage analysis on comorbidity of alcohol dependence and habitual smoking revealed a modest peak on chromosome 2 around 90 cM, while evidence for linkage to our region of interest was weak and inconsistent in that study [13]. Linkage to activity of platelet monoamine oxidase utilizing the COGA dataset was found on chromosome 2 [14]. The region of chromosome 2 in which we found evidence of linkage is consistent with some previous results found for eletrophysiological variables [15] utilizing this same dataset.
