# Novel BMP2K::PDGFRA fusion in an unusual myeloid/lymphoid neoplasm with eosinophilia

## TL;DR

A new BMP2K::PDGFRA fusion is identified in a rare blood cancer with high eosinophil counts, suggesting the need for broader testing.

## Contribution

The discovery of a novel BMP2K::PDGFRA fusion in a myeloid/lymphoid neoplasm with eosinophilia.

## Key findings

- An in-frame BMP2K::PDGFRA fusion was detected in a patient with an unusual myeloid neoplasm.
- DNA sequencing revealed a pathogenic TP53 mutation but no mutations in KIT, JAK2, CALR, or MPL.
- The case highlights the potential for novel PDGFRA fusion partners to respond to tyrosine kinase inhibitors.

## Abstract

Myeloid and/or lymphoid neoplasms with eosinophilia PDGFRA gene fusions usually occur with FIP1L1 as the partner gene; however, novel partners have been described. These novel partners are sometimes responsive to tyrosine kinase inhibitor therapy.

We describe here a patient with a PDGFRA fusion with a previously undescribed partner gene, BMP2K.

RNA sequencing with the Archer Fusion Plex Pan Solid Tumor Panel (IDT) was used to detect fusions. DNA sequencing using a custom IDT panel was also performed.

An in-frame BMP2K::PDGFRA
fusion was detected in a patient who had an ill-defined myeloid neoplasm with eosinophilia. The myeloid neoplasm had a prominent mast cell component and myeloid blast component in the lymph node, while the bone marrow showed hypercellularity, eosinophilia, and myelofibrosis. DNA NGS revealed a pathogenic TP53 mutation but was negative for mutations in other genes including KIT, JAK2, CALR, and MPL.

Given that PDGFRA fusions with novel fusion partners may respond to tyrosine kinase inhibitor therapy, partner agnostic testing methods should be considered either up front or as reflex testing in patients with myeloid and/or lymphoid neoplasms with blood, bone marrow, or tissue eosinophilia.