IGH::FENDRR and specific KRAS mutations define a novel B-ALL molecular subtype with poor chemotherapy response

Large scale sequencing efforts have defined up to 27 diagnostic entities in B-ALL, leaving few samples without subtype assignment. Extended genomic and transcriptomic profiling in routine diagnostics broadens the sample collection and holds the potential to identify novel B-ALL subtypes. By analyzing an aggregated set of 4,857 B-ALL patients from three cohorts, we identified a novel group of twenty cases (age 18-66 years, median: 34 years) characterized by a previously undescribed IGH::FENDRR re