Limitations on the number of individuals who could be genotyped for GAW14 led us to construct a family sample of 1,353 individuals drawn from both the initial and replication datasets (Figure 1). With non-genotyped individuals included for linking in the pedigrees, the 143 families totalled 1,614 individuals. We selected the sample starting with a core of informative families with at least 6 members who had been interviewed and genotyped, even if they did not have electrophysiological data. Family size ranged from 6 to 30. Other phenotypes forwarded for analysis included alcohol dependence, habitual smoking, and the maximum number of drinks in a 24-hour period. Of the 1,353 individuals selected for genotyping, 1,005 subjects had eyes closed EEG data available, while 905 subjects had Visual Oddball ERP/ERO data available.
