Beyond limitations in our selection of candidate genes, the SAGE dataset has limitations that restrict the interpretation of our results. First, some of the most well studied variants were not covered in SAGE and therefore could not be assessed. Second, the X chromosome is not included in the publically available SAGE results so we were unable to investigate genes on the X chromosome. Specifically, two candidate genes on the X chromosome, MAOA and HTR2C that had 26 and 8 publications respectively, were not assessed. Third, SAGE is limited in its power to identify genotyped variants on the GWA chip that have small effect sizes. Despite the fact that the SAGE dataset was relatively large when it was originally published, identifying common variants with small effect sizes (<1.1) remains challenging and we are unable to rule out the possibility of real but modest effects of these genes. Forth, variants that are uncommon (1%-5%) or rare (<1%) in the study population may also not be detected in SAGE because of their individually small contribution to overall alcoholism. Fifth, the SAGE dataset primarily
