VARiant PRIoritization SuM (VARPRISM) is a software package that identifies genes with a statistical excess of damaging de novo mutations among individuals with a genetic disease. VARPRISM incorporates functional variant prediction information (the VAAST CASM score) to improve the statistical power of risk gene mapping and controls for local mutation rate heterogeneity. The beta version of VARPRISM is currently available for download. More information on VARPRISM will be available upon manuscript publication.