Jumping translocation at IIq23 with MLL gene rearrangement and interstitial telomeric sequences

We report a case of acute myeloid leukemia (AML) M5a showing a jumping tran slocation with a breakpoint at 11q23. Fluorescence in situ hybridization (F ISH) demonstrated triplication of the MLL gene and the presence of intersti tial telomeric sequences, supporting the role of repetitive sequences in th e mechanism of jumping translocations. Southern blot analysis of the MLL br eakpoint cluster region showed the presence of an MLL gene rearrangement, j umping translocation with MLL gene rearrangement is a previously unreported phenomenon in leukemia cytogenetics. Genes Chromosomes Cancer 24:295-298, 1999. (C) 1999 Wiley-Liss, Inc.