Open AccessIdentification of MLL partner genes in 27 patients with acute leukemia from a single cytogenetic laboratory
Author(s) -
De Braekeleer Etienne,
Meyer Claus,
Douet-Guilbert Nathalie,
Basinko Audrey,
Le Bris Marie-Josée,
Morel Frédéric,
Berthou Christian,
Marschalek Rolf,
Férec Claude,
De Braekeleer Marc
Publication year - 2011
Publication title -
molecular oncology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.332
H-Index - 88
eISSN - 1878-0261
pISSN - 1574-7891
DOI - 10.1016/j.molonc.2011.08.003
Subject(s) - fusion gene , chromosomal translocation , fluorescence in situ hybridization , biology , acute leukemia , leukemia , chromosomal rearrangement , gene , cancer research , gene rearrangement , acute myeloblastic leukemia , genetics , microbiology and biotechnology , karyotype , chromosome
Chromosomal rearrangements involving the MLL gene have been associated with many different types of hematological malignancies. Fluorescent in situ hybridization with a panel of probes coupled with long distance inverse‐PCR was used to identify chromosomal rearrangements involving the MLL gene. Between 1995 and 2010, 27 patients with an acute leukemia were found to have a fusion gene involving MLL . All seven ALL patients with B cell acute lymphoblastic leukemia were characterized by the MLL/AFF1 fusion gene resulting from a translocation (5 patients) or an insertion (2 patients). In the 19 AML patients with acute myeloblastic leukemia, 31.6% of all characterized MLL fusion genes were MLL/MLLT3 , 21.1% MLL/ELL , 10.5% MLL/MLLT6 and 10.5% MLL/EPS15 . Two patients had rare or undescribed fusion genes, MLL/KIAA0284 and MLL/FLNA . Seven patients (26%) had a complex chromosomal rearrangement (three‐way translocations, insertions, deletions) involving the MLL gene. Splicing fusion genes were found in three patients, leading to a MLL/EPS15 fusion in two and a MLL/ELL fusion in a third patient. This study showed that fusion involving the MLL gene can be generated through various chromosomal rearrangements such as translocations, insertions and deletions, some being complex or cryptic. A systematic approach should be used in all cases of acute leukemia starting with FISH analyses using a commercially available MLL split signal probe. Then, the analysis has to be completed, if necessary, by further molecular cytogenetic and genomic PCR methods.