[Molecular genetics of acute lymphoblastic leukemia]

Acute lymphoblastic leukemia (ALL), a clonal expansion of hematopoietic blasts, is a highly heterogeneous disease comprising many entities for which distinct treatment strategies are pursued. Recurrent defects including chromosomal translocations, aneuploidies, and gene-specific alterations generate molecular subgroups of B- and T-ALL with differing clinical courses and distinct responses to therapy. Herein, we review the spectrum of genetic aberrations that promote acute B- and T-ALL, as well as the currently-revealed mechanisms of cell transformation and malignant progression. Although 5-year overall survival of childhood ALL patients has improved to as much as 90% due to progress in chemotherapy and other supporting therapeutic modalities, including allo-HSCT, the prognosis is still poor for the remaining 10% of cases, which consist mainly of MLL-AF4-positive ALL and bcr-abl positive ALL. The prognosis of adults with ALL is not satisfactory and adult ALL remains a challenging disease. The development of novel methodologies, including new molecular therapeutic targets, is also needed to improve the prognosis of ALL.