BTG1 deletions do not predict outcome in Down syndrome acute lymphoblastic leukemia

Children with Down syndrome (DS) have an increased risk of developing acute myeloid and B-cell precursor acute lymphoblastic leukemia (BCP-ALL).1 The prognosis of DS ALL is at best similar and often inferior to that of sporadic ALL (non-DS) patients.2, 3 DS ALL is characterized by unique biological features when compared with non-DS ALL. For instance, DS ALL has a lower frequency of the favorable genetic abnormalities t(12;21)(p13;q22) (ETV6–RUNX1) and the unfavorable t(9;22)(q34;q11) (BCR-ABL1),3, 4 but a higher frequency of JAK2 mutations and CRLF2 rearrangements. Using genome-wide screening techniques, several (novel) genomic aberrations involved in the pathogenesis of (non-) DS ALL were identified. The potential prognostic impact of most of these novel aberrations and whether these patients may benefit from specific therapies targeted to these unique genetic features needs to be investigated further.