We report here results for a GWAS for OD in two different population groups in the United States. We made use of GWAS and replication samples collected by us and available data from the SAGE project, which were collected using a similar psychiatric interview, were used for replication. Several of the top-ranked genes encode proteins that participate in potassium and calcium signaling pathways. Although calcium signaling genes have been studied in addiction biology, they were not previously considered key genetic candidates. These findings therefore add substantially to our knowledge of the biology of OD. Our most compelling results were obtained in the AA population.
