A semiquantitative whole genome screen analysis of alcohol dependence

Two whole genome screens were applied to sibling pairs from the Collaborative Study on the Genetics of Alcoholism (COGA) family data to compare a semiquantitative method with a standard qualitative approach. The semiquantitative method used a score derived from 11 symptoms, and the qualitative approach used the COGA criteria for alcohol dependence. There was no concordance in the regions identified by the two models. Three regions of nominal significance were identified using the symptom score. In these three regions, correlated traits were also analyzed to determine whether linkage could be attributed to their intermediate effect. The evidence for linkage to one locus on chromosome 6 could be explained by linkage to the personality trait harm avoidance.