[Identification of TCF3-ZNF384 fusion by transcriptome sequencing in B cell acute lymphoblastic leukemia and its laboratory and clinical characteristics].

OBJECTIVE

To detect fusion gene with pathological significance in a patient with refractory and relapsed acute B cell lymphoblastic leukemia (B-ALL) and to explore its laboratory and clinical characteristics.

METHODS

Transcriptome sequencing was used to detect potential fusion transcripts. Other laboratory results and clinical data of the patient were also analyzed.

RESULTS

The patient was found to harbor TCF3 exon 17-ZNF384 exon 7 in-frame fusion transcript. The minimal residual disease (MRD) has remained positive after multiple chemotherapy protocols including CD19-, CD22- targeted chimeric antigen receptor T cells immunotherapy. The patient eventually achieved complete remission and sustained MRD negativity after allogeneic hemopoietic stem cell transplantation (allo-HSCT).

CONCLUSION

Transcriptome sequencing can effectively detect potential fusion genes with clinical significance in leukemia. TCF3-ZNF384 positive B-ALL has unique laboratory and clinical characteristics, may not well respond to chemotherapy and immunotherapy, and is more likely to relapse. Timely allo-HSCT treatment may help such patients to achieve long-term disease-free survival. TCF3-ZNF384 positive B-ALL is not uncommon in pediatric patients but has not been effectively identified.