KMT2A::NRIP3 Fusion Gene in the First Reported Case of B-Cell Acute Lymphoblastic Leukemia.

BACKGROUND

The KMT2A rearrangements is primarily caused by balanced translocations, with only a very small fraction resulting from deletions or inversions within the long arm of chromosome 11.

OBSERVATIONS: We present a rare case of KMT2A::NRIP3 fusion-positive B-ALL identified through whole transcriptome sequencing (WTS) resulting from pericentric inversion of chromosome 11. Whole-genome sequencing (WGS) analysis revealed that the breakpoints of the KMT2A::NRIP3 fusion were located deep within intron 8 of KMT2A and intron 1 of NRIP3 , accompanied by a pathogenic hotspot mutation (p.Pro74Leu) in the MYC gene. In addition, we found that NRIP3 may negatively regulate Cyclin D1 ( CCND1 ) in acute myeloid leukemia (AML) but not in B-ALL patients.

CONCLUSIONS

The rare KMT2A::NRIP3 fusion gene can be observed not only in pediatric AML patients, but also in B-ALL patients.