Identification of a novel fusion gene involving hTAFII68 and CHN from a t(9;17)(q22;q11.2) translocation in an extraskeletal myxoid chondrosarcoma.

A proportion of extraskeletal myxoid chondrosarcomas (EMC) have been shown to have a characteristic translocation t(9;22)(q22;q12) involving the EWS gene at 22q12 and the CHN orphan nuclear receptor gene at 9q22. This translocation appears to be largely specific for EMC, but has not been detected in all such tumours. We report here a case of EMC with a t(9;17)(q22;q11.2) as the sole chromosome abnormality. We have determined that the translocation results in the fusion of the entire coding region of CHN to the N-terminal transactivation domain of RBP56/hTAFII68. This is the first report of a translocation involving RBP56/hTAFII 68, a protein with sequence homology to both EWS and TLS/FUS. The involvement of RBP56/hTAFII68 may explain some unusual features of the tumour.