Acute lymphoblastic leukaemia, a clinically and biologically heterogeneous disease, represents the most common malignant disease in childhood. Approximately 20–25% of B-cell precursor acute lymphoblastic leukaemia in childhood carry the cryptic chromosomal translocation t(12;21)(p13;q22). This translocation combines two transcription factors and essential regulators of normal haematopoiesis, ETV6 and RUNX1, into the fusion oncogene ETV6/RUNX1 (formerly known as TEL/AML1). Recent studies in various animal models have strengthened the view that ETV6/RUNX1-positive cells give rise to pre-leukemic clones with a differentiation block in the pro/pre-B stage of B-cell development that, after acquisition of additional mutations, may transform into full malignancy. Despite the favourable prognostic parameters of this B-cell precursor acute lymphoblastic leukaemia subgroup, relapse and resistance to chemotherapeutics do occur and increased knowledge of the molecular mechanisms underlying ETV6/RUNX1-driven leukaemia is essential to develop novel therapeutic strategies to selectively target ETV6/RUNX1-positive leukaemia. In this manuscript, an overview of the most recent genetic insights in ETV6/RUNX1-positive B-cell precursor acute lymphoblastic leukaemia is given.

(BELG J HEMATOL 2017;8(5):179–84)