title: Identification of MLL partner genes in 27 patients with acute leukemia from a single cytogenetic laboratory.
abstract: 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.
authors: Université de Brest, Faculté de Médecine et des Sciences de la Santé, Brest, France.
authors: Etienne
authors: E
authors: De Braekeleer
authors: Claus
authors: C
authors: Meyer
authors: Nathalie
authors: N
authors: Douet-Guilbert
authors: Audrey
authors: A
authors: Basinko
authors: Marie-Josée
authors: MJ
authors: Le Bris
authors: Frédéric
authors: F
authors: Morel
authors: Christian
authors: C
authors: Berthou
authors: Rolf
authors: R
authors: Marschalek
authors: Claude
authors: C
authors: Férec
authors: Marc
authors: M
authors: De Braekeleer
mesh_terms: D000328:Adult; D000368:Aged; D020732:Cytogenetic Analysis; D005260:Female; D015973:Gene Expression Regulation, Leukemic; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D051788:Myeloid-Lymphoid Leukemia Protein / Q000235:genetics*; D015514:Oncogene Proteins, Fusion / Q000235:genetics*; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics*; D055815:Young Adult
chemical_list: D015514:Oncogene Proteins, Fusion; D051788:Myeloid-Lymphoid Leukemia Protein