Prognostic impact of FLT3 gene expression and mutational status in pediatric MLL-rearranged ALL

MLL-rearranged acute lymphoblastic leukemias (ALLs) are characterized by high levels of FLT3 gene expression. In addition, activating FLT3 mutations have been reported to be frequent secondary genetic events. However, the prognostic impact of both FLT3 gene expression and its mutational status remains controversial within this cytogenetic subgroup. We analyzed the presence of FLT3-internal tandem duplication (ITD) and FLT3-tyrosine kinase domain (TKD) mutations as well as the FLT3 gene expression levels in a large cohort of pediatric MLL-rearranged ALLs. All samples were tested negative for FLT3-ITD mutations. B…