A common 93-kb duplicated DNA sequence at 1q21.2 in acute lymphoblastic leukemia and Burkitt lymphoma

In three patients with acute lymphoblastic leukemia (ALL) and in another with Burkitt lymphoma (BL), conventional cytogenetics and fluorescence in situ hybridization (FISH), applied singly or in combination, showed lq duplication in two cases of ALL with hyperdiploid karyotypes, Iq duplication resulting from an unbalanced translocation in a third case of ALL, and inv dup(1)(q) in a patient with BL. Centromeric or telomeric breakpoints and extension of the Iq duplicons varied in each case. FISH defined a minimal, common duplicated region of 93kb at band lq2l.2 corresponding to clone RP11-212K13. In this region three putative oncogenes or tumor suppressor genes have been mapped: SF3B4 (splicing factor 3b, subunit 4), OTUD7B (OTU domain containing 713), and MTMR11 (myotubularin related protein 11). For the first time, a minimal common lq21.2 duplicated sequence has been identified in lymphoid malignancies in a region where putative oncogenes or suppressor genes have been mapped. This finding elucidates the genomic background of ALL and BL with Iq duplication and provides the basis for molecular studies investigating which genes are involved in leukemogenesis or disease progression in these cases. (C) 2007 Elsevier Inc. All rights reserved.