POU2AF3
Overview
POU2AF3 (POU class 2 homeobox associating factor 3) encodes a transcriptional coactivator. It is recognized as an EWSR1 fusion partner in a rare subtype of undifferentiated small round cell sarcomas within the WHO 2020 “round cell sarcoma with EWSR1-non-ETS fusions” category.
Alterations observed in the corpus
- Discussed as a characterised EWSR1-non-ETS fusion partner in the WHO 2020 “round cell sarcoma with EWSR1-non-ETS fusions” category, alongside EWSR1::BEND2, EWSR1::NFATC2, and EWSR1::PATZ1; mentioned in the differential diagnostic context of a bladder EWSR1::BEND2 sarcoma case PMID:28199314.
Cancer types (linked)
- Undifferentiated small round cell sarcoma (SARC): EWSR1::POU2AF3 fusions are a WHO-recognized sarcoma subtype distinct from classical Ewing sarcoma PMID:28199314.
Co-occurrence and mutual exclusivity
- EWSR1::POU2AF3 is mutually exclusive with canonical EWSR1::FLI1 Ewing sarcoma fusions; part of the EWSR1-non-ETS group PMID:28199314.
Therapeutic relevance
- No specific targeted therapy reported; Ewing-sarcoma-like chemotherapy protocols are used in the absence of dedicated trials for EWSR1-non-ETS fusion sarcomas PMID:28199314.
Open questions
- Classification of EWSR1-non-ETS fusion sarcomas (BEND2, NFATC2, PATZ1, POU2AF3) — whether site/morphology should split or merge these entities within WHO taxonomy remains unresolved PMID:28199314.
Sources
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