BCOR internal tandem duplication and YWHAE-NUTM2B/E fusion are mutually exclusive events in clear cell sarcoma of the kidney.

Clear cell sarcoma of the kidney (CCSK) is the second most common pediatric renal tumor. Two recurrent genetic aberrations have been described in CCSK. One is a fusion of YWHAE and NUTM2B/E, the other is an internal tandem duplication (ITD) in the BCOR gene. Here it is shown that YWHAE-NUTM2B/E fusion and the BCOR ITD are mutually exclusive events and activated different downstream signaling systems. This has important diagnostic implications and opens up for further mechanistic studies of CCSK pathogenesis.