Peterson, Jess F.; Smoley, Stephanie A.; Luoma, Ivy M.; Pitel, Beth A.; Rice, Christopher S.; Demasi, Jonna C. Benevides; Vasmatzis, George; Smadbeck, James B.; Yang, Tong; Greipp, Patricia T.; Ketterling, Rhett P.; Baughn, Linda B.
The detection of recurrent chromosomal rearrangements in B-lymphoblastic leukemia/lymphoma (B-ALL/LBL) is critical for patient management decisions. We present a newly diagnosed case of B-ALL in a young adult with a cryptic KMT2A/AFF1 fusion that was unappreciable by conventional chromosome and fluorescence in situ hybridization (FISH) KMT2A break-apart probe studies. To further characterize this abnormality, a next-generation sequencing strategy, mate-pair sequencing (MPseq) was performed and characterized a cryptic, insertional rearrangement that created KMT2A/AFF1 gene fusion. This case highlights the superior precision and resolution capabilities of NGS when compared to traditional cytogenetic methodologies, including conventional chromosome and FISH studies.