# B/T Mixed Phenotype Acute Leukaemia Harbouring NUP98::BPTF Fusion

## TL;DR

A rare case of mixed B/T acute leukemia with a NUP98::BPTF fusion is reported, offering new insights into its genetic features and treatment challenges.

## Contribution

This is the first case study of B/T mixed phenotype acute leukemia with NUP98::BPTF fusion and T-lineage characteristics.

## Key findings

- The patient had a t(11;17)(p15;q23)/NUP98::BPTF fusion and mutations in NOTCH1, FBXW7, and PHF6.
- The patient failed initial T-ALL-directed chemotherapy but achieved remission after consolidation therapy.
- This case provides new clinicopathological and genomic insights into NUP98::BPTF-rearranged leukemia.

## Abstract

NUP98::BPTF rearranged (r) leukaemia is rare with only five reported cases, including acute myeloid leukemia and T‐lymphoblastic leukemia (T‐ALL).

Herein, we report a case of NUP98::BPTF‐r mixed phenotype acute leukemia (MPAL), B/T with T‐lineage‐predominance in a 15‐year‐old female. Cytogenetic and molecular studies revealed a t(11;17)(p15;q23)/NUP98::BPTF fusion and cooperative gene alterations characteristic of T‐ALL (NOTCH1, FBXW7, and PHF6). Our patient had a primary induction failure with T‐ALL‐directed chemotherapy and achieved complete remission following consolidation.

This is the first case study characterizing the clinicopathological and genomic features of B/T MPAL harboring NUP98::BPTF fusion and providing insights into molecular pathogenesis.

The authors have confirmed clinical trial registration is not needed for this submission.