571 Background: Renal medullary carcinoma (RMC) is a rare and highly aggressive malignancy that affects primarily young adults with sickle cell trait. The prognosis of RMC is poor with a median survival of about 12 months from diagnosis. It has been previously shown that loss of heterozygosity of SMARCB1 occurs in the majority of cases leading to protein loss. However, a comprehensive molecular profiling of this disease remains unknown. Methods: Whole-exome sequencing (WES) of 9 RMC matched tumor-normal cases and 1 unmatched case were performed. In addition, single nucleotide polymorphism (SNP) analysis was done using the Affymetrix SNP 6.0 array. To test differentially expressed genes between RMC cases and normal kidney, RNA sequencing was carried out. The effect of EZH2 inhibition on in vitro RMC tumor cell proliferation was assessed using the MTT assay. Results: WES analysis of 9 paired RMC cases identified 233 non-synonymous somatic mutations (median: 21; range: 12-44). We observed frequent mutations ...