Genomic landscape of pediatric B-other acute lymphoblastic leukemia in a consecutive European cohort

Haematologica. 2019 Jul;104(7):1396-1406. doi: 10.3324/haematol.2018.204974. Epub 2019 Jan 10.


Novel biological subtypes and clinically important genetic aberrations (druggable lesions, prognostic factors) have been described in B-other acute lymphoblastic leukemia (ALL) during the last decade; however, due to a lack of studies on unselected cohorts, their population frequency and mutual associations still have to be established. We studied 110 consecutively diagnosed and uniformly treated childhood B-other patients using single nucleotide polymorphism arrays and whole exome/transcriptome sequencing. The frequency of DUX4-rearranged, BCR-ABL1-like, ZNF384-rearranged, ETV6-RUNX1-like, iAMP21 and MEF2D-rearranged subtypes was 27%, 15%, 5%, 5%, 4%, and 2%, respectively; 43% of cases were not classified into any of these subtypes (B-rest). We found worse early response to treatment in DUX4-rearranged leukemia and a strong association of ZNF384-rearranged leukemia with B-myeloid immunophenotype. Of the druggable lesions, JAK/STAT-class and RAS/RAF/MAPK-class aberrations were found in 21% and 43% of patients, respectively; an ABL-class aberration was found in one patient. A recently described negative prognostic factor, IKZF1plus , was found in 14% of patients and was enriched in (but not exclusive for) BCR-ABL1-like subtype. PAX5 fusions (including 4 novel), intragenic amplifications and P80R mutations were mutually exclusive and only occurred in the B-rest subset, altogether accounting for 20% of the B-other group. PAX5 P80R was associated with a specific gene expression signature, potentially defining a novel leukemia subtype. Our study shows unbiased European population-based frequencies of novel ALL subtypes, recurrent (cyto)genetic aberrations and their mutual associations. This study also strengthens and widens the current knowledge of B-other ALL and provides an objective basis for optimization of current genetic diagnostics.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Biomarkers, Tumor / genetics*
  • Child
  • Child, Preschool
  • Chromosome Aberrations*
  • Cohort Studies
  • Europe
  • Female
  • Follow-Up Studies
  • Gene Expression Regulation, Neoplastic
  • Genomics / methods*
  • Humans
  • Infant
  • Male
  • Mutation*
  • Oncogene Proteins, Fusion / genetics*
  • Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / epidemiology
  • Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / genetics*
  • Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / pathology
  • Prognosis
  • Transcriptome*


  • Biomarkers, Tumor
  • Oncogene Proteins, Fusion