PTPRD copy number variants and Ewing's sarcoma: Strengthening the association and therapeutic implications.

Ewing sarcoma (ES), a common pediatric primary bone neoplasm, has a well-defined genomic landscape with various predisposing genomic elements including TP53, PMS2 and RET. Additionally, germline and somatic variants in protein tyrosine phosphatase delta (PTPRD), a tumor suppressor gene, have been identified in a limited number of ES patients. Here we present an ES patient, remarkable in terms of his young age and extent at presentation, found to have a PTPRD CNV. We explore the pathogenicity of this CNV, describe the patient's clinical course and touch upon the potential therapeutic implications in this subset of patients.