Inv(11)(q21q23) fuses MLL to the Notch co-activator mastermind-like 2 in secondary T-cell acute lymphoblastic leukemia
Abstract
The human MLL gene is frequently involved in genetic rearrangements, all of which associated with malignancies of the hematopoietic system. More than 50 rearrangements have so far been characterized at the molecular level; however, only a small portion of these MLL fusions can be recurrently identified in therapy-related malignancies.
Secondary leukemias usually present as myelodysplastic syndrome or therapy-related acute myeloid leukemia (t-AML) and are characterized by the localization of the genomic breakpoint in a subregion of the MLL breakpoint cluster region, associated with specific sequence features indicating that topoisomerase II inhibition by etoposide treatment may be involved in t-AML induction. Genetic rearrangements of MAML2 have first been described for a subset of salivary gland tumors.
Fusions between MLL and MAML2 have recently been reported for two adult leukemia patients with secondary AML and myelodysplastic syndrome.