Could One Test Replace Multiple Leukemia Assays?

May 29, 2026

The Pathologist

Overview

A new long-read sequencing approach, FUSILLI, shows promise in detecting fusion oncogenes in pediatric B-cell acute lymphoblastic leukemia (B-ALL). This method identifies key gene fusions in a single workflow.

Background

Pediatric B-ALL is one of the most common childhood cancers, and accurate detection of fusion oncogenes is crucial for diagnosis and treatment. Current methods require multiple laboratory tests.

Data Highlights

Sample Group	Average Reads per Sample	Sensitivity	Specificity
High-depth	11.2 million	Highest	High
Low-depth	Specify number	Lower	Not specified

Key Findings

FUSILLI showed high sensitivity for detecting clinically relevant fusions in high-depth samples.
Key fusion types identified include ETV6::RUNX1, BCR::ABL1, TCF3::PBX1, and MEF2D::HNRNPUL1.
Approximately 10 million reads per sample are estimated to be necessary for optimal fusion detection performance.
FUSILLI required less computing time and memory compared to other fusion detection tools.
The method can identify secondary genomic alterations.

Clinical Implications

The FUSILLI tool may provide a more efficient and comprehensive approach for molecular profiling in pediatric B-ALL. Its ability to streamline testing could facilitate quicker diagnosis and treatment decisions.

Conclusion

Long-read whole-transcriptome sequencing represents an advancement in the molecular classification of pediatric B-ALL, though further validation is necessary.