Importantly, these tumors show frequent and specific rearrangement of the Ewing sarcoma breakpoint region 1
(EWSR1) gene located on chromosome 22 [5, 6].
(24) The EWSR1 gene, located at 22q12.2, encodes the eponymous Ewing sarcoma breakpoint region 1
(EWSR1) protein, which is a member of the TET family of transcription factors.
(2) In addition, most CCS show rearrangement of the EWSR1 (Ewing sarcoma breakpoint region 1
) locus, which in most cases leads to fusion of the EWSR1 gene with the activating transcription factor-1 gene (ATFT) in a recurrent translocation, t(12;22)(q13;q12).
A dual color assay using the break apart translocation probe EWSR1 (Ewing sarcoma breakpoint region 1
) was performed to look for a rearrangement of the EWSR1 locus at 22q12 because in abnormalities of EWS, translocations are frequently found in Ewing sarcoma/primitive neuroectodermal tumor with the translocation partner typically FLI1, 11Q24, or ERG, 21Q22.3.