Insertion of chromosome 11 in chromosome 4 resulting in a 5'MLL-3'AF4 fusion gene in a case of adult acute lymphoblastic leukemia.
We report on a 69-year-old woman with B-lineage acute lymphoblastic leukemia. Cytogenetic studies at diagnosis with R banding showed an insertion, ins(4;11)(q21;q13q23). Fluorescence in situ hybridization (FISH) with whole chromosome painting probes confirmed the insertion of chromosome 11 material into chromosome 4. FISH using the MLL probe showed the translocation of the 5' end of MLL into chromosome 4. Since the 5'MLL-3'AF4 fusion transcript was detected by a reverse transcriptase polymerase chain reaction, we concluded that the insertion of part of chromosome 11 split the AF4 gene in two, resulting in the presence of the 5'MLL-3'AF4 fusion gene on the der(4) instead of the der(11), as commonly observed. Our findings stress the value of combining banding cytogenetics with FISH and molecular techniques to better assess rearrangements in leukemia.
Morel
Frédéric
F
Service de Cytogénétique, Cytologie et Biologie de la Reproduction, CHU Morvan, Brest, France.
Le Bris
Marie-Josée
MJ
Douet-Guilbert
Nathalie
N
Duchemin
Jérôme
J
Herry
Angèle
A
Le Calvez
Geneviève
G
Marion
Véronique
V
Berthou
Christian
C
De Braekeleer
Marc
M
D000368:Aged; D002880:Chromosomes, Human, Pair 11; D002894:Chromosomes, Human, Pair 4; D005260:Female; D006801:Humans; D051788:Myeloid-Lymphoid Leukemia Protein; D015514:Oncogene Proteins, Fusion / Q000032:analysis*; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics*; D014178:Translocation, Genetic
C113855:MLL-AF4 fusion protein, human; D015514:Oncogene Proteins, Fusion; D051788:Myeloid-Lymphoid Leukemia Protein