MLL translocations with concurrent 3' deletions: interpretation of FISH results.
Date
2004-11ICR Author
Author
Barber, KE
Ford, AM
Harris, RL
Harrison, CJ
Moorman, AV
Type
Journal Article
Metadata
Show full item recordAbstract
Rearrangements involving the MLL gene at 11q23 occur in a clinically relevant subgroup of patients with acute lymphoblastic leukemia (ALL) at all ages, and therefore their accurate identification at diagnosis is important. It has become commonplace to screen ALL patients for rearrangements of MLL using a dual-color fluorescence in situ hybridization (FISH) assay. We report on 12 ALL patients with an unusual FISH result consisting of the following signal pattern: one 5' green, no 3' red, and one/two fusion signals. This configuration is consistent with a MLL translocation and simultaneous deletion of 3' MLL-a well-established phenomenon-which has been interpreted as a positive result. G-banded and complementary metaphase FISH analyses confirmed an 11q23/MLL translocation in 8 of the 12 cases, whereas in one case, the identification of a del(11)(q23) was restricted to G-banded analysis only. In three cases, an MLL rearrangement was excluded by extensive FISH analysis and/or Southern blotting. In conclusion, the loss of the 3' MLL signal should not be assumed to be the result of a concurrent translocation and deletion event, and such aberrant FISH signal patterns should be investigated further by alternative methods for determining their MLL status.
Collections
Subject
Chromosomes, Human, Pair 11
Humans
Translocation, Genetic
Histone-Lysine N-Methyltransferase
DNA-Binding Proteins
Transcription Factors
Blotting, Southern
Chromosome Banding
In Situ Hybridization, Fluorescence
Karyotyping
Metaphase
Gene Deletion
Proto-Oncogenes
Child
Child, Preschool
Infant
Female
Male
Myeloid-Lymphoid Leukemia Protein
Statistics as Topic
Precursor Cell Lymphoblastic Leukemia-Lymphoma
Research team
Biology of Childhood Leukaemia
Language
eng
License start date
2004-11
Citation
Genes, chromosomes & cancer, 2004, 41 (3), pp. 266 - 271