title: MLL tandem duplication in two cases of acute myelocytic leukemia with unbalanced translocations: der(16)t(11;16)(q23;p13) and der(18)t(11;18)(q22;p11.2).
abstract: We describe two cases of acute myelocytic leukemia (AML), classified as M4 and M1 in the French-American-British classification, with unbalanced translocations der(16)t(11;16)(q23;p13) and der(18)t(11;18) (q22;p11.2), respectively. Molecular studies using Southern blot and reverse transcriptase-polymerase chain reaction showed an MLL rearrangement due to an internal duplication of the gene in both cases. Fluorescence in situ hybridization disclosed the presence of an extra copy of the MLL gene on 16p13 and 18p11.2, respectively, as a result of the partial trisomy of chromosome 11q. Our two cases clearly show that tandem duplication of the MLL gene may occur in AML with a partial 11q trisomy. Thus, systematic screening of this molecular defect should be performed in patients with unbalanced translocations involving 11q22 approximately q23-->qter.
authors.affiliation: Department of Hematology, University Hospital Sant Pau, Aveñida Sant Antoni Ma Claret 167, UAB, 08025 Barcelona, Spain. aaventin@hsp.santpau.es
authors.forename: A
authors.initials: A
authors.lastname: Aventín
authors.forename: R
authors.initials: R
authors.lastname: La Starza
authors.forename: S
authors.initials: S
authors.lastname: Casas
authors.forename: J
authors.initials: J
authors.lastname: Nomdedéu
authors.forename: M P
authors.initials: MP
authors.lastname: Queipo de Llano
authors.forename: G
authors.initials: G
authors.lastname: Cimino
authors.forename: F
authors.initials: F
authors.lastname: Lo Coco
authors.forename: J
authors.initials: J
authors.lastname: Sierra
authors.forename: C
authors.initials: C
authors.lastname: Mecucci
mesh_terms: D000328:Adult; D015139:Blotting, Southern; D002877:Chromosomes, Human; D020732:Cytogenetic Analysis; D004268:DNA-Binding Proteins / Q000235:genetics*; D005260:Female; D020440:Gene Duplication; D011495:Histone-Lysine N-Methyltransferase; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D015470:Leukemia, Myeloid, Acute / Q000209:etiology / Q000235:genetics* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D051788:Myeloid-Lymphoid Leukemia Protein; D011519:Proto-Oncogenes; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors; D014178:Translocation, Genetic
chemical_list: D004268:DNA-Binding Proteins; C497422:KMT2A protein, human; D014157:Transcription Factors; D051788:Myeloid-Lymphoid Leukemia Protein; D011495:Histone-Lysine N-Methyltransferase