A number of samples provide the bases for these analyses. In analyzing data from these samples, we focus on clusters of genomic markers whose allele frequencies distinguish control individuals from those with substance dependence or addiction-related phenotypes. We describe identification of chromosomal regions that contain clusters of such nominally-positive results in replicate samples for addiction vulnerability. We then describe evidence for generalization that arises from identification of overlapping chromosomal locations of clustered positive results for different phenotypes. These data thus support pleiotropic influences (eg contributions of the same allelic variants to multiple phenotypes) of common allelic variants on several of the brain based phenotypes. The data thus document overlapping heritable influences on several interesting brain phenotypes.
