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MLL Amplification (mll + amplification)
Selected AbstractsDistinct sequences on 11q13.5 and 11q23,24 are frequently coamplified with MLL in complexly organized 11q amplicons in AML/MDS patientsGENES, CHROMOSOMES AND CANCER, Issue 4 2004Andrea Zatkova Amplification within chromosome arm 11q involving the mixed-lineage leukemia gene (MLL) locus is a rare but recurrent aberration in acute myeloid leukemia and myelodysplastic syndrome (AML/MDS). We and others have observed that 11q amplifications in most AML/MDS cases have not been restricted to the chromosomal region surrounding the MLL gene. Therefore, we implemented a strategy to characterize comprehensively 11q amplicons in a series of 13 AML/MDS patients with MLL amplification. Analysis of 4 of the 13 cases by restriction landmark genomic scanning in combination with virtual genome scan and by matrix-based comparative genomic hybridization demonstrated that the 11q amplicon in these four cases consisted of at least three discontinuous sequences derived from different regions of the long arm of chromosome 11. We defined a maximally 700-kb sequence around the MLL gene that was amplified in all cases. Apart from the core MLL amplicon, we detected two additional 11q regions that were coamplified. Using fluorescence in situ hybridization (FISH) analysis, we demonstrated that sequences in 11q13.5 and 11q23,24 were amplified in 8 of 13 and 10 of 12 AML/MDS cases, respectively. Both regions harbor a number of potentially oncogenic genes. In all 13 cases, either one or both of these regions were coamplified with the MLL amplicon. Thus, we demonstrated that 11q amplicons in AML/MDS patients display a complex organization and have provided evidence for coamplification of two additional regions on the long arm of chromosome 11 that may harbor candidate target genes. © 2004 Wiley-Liss, Inc. [source] Chromosome 11 rearrangements and specific MLL amplification revealed by spectral karyotyping in a patient with refractory anaemia with excess of blasts (RAEB)BRITISH JOURNAL OF HAEMATOLOGY, Issue 5 2003Giuseppe Calabrese Summary. A patient with refractory anaemia with excess of blasts (RAEB) had a complex karyotype with multiple markers. Spectral karyotyping (SKY) showed rearrangements including three different der(11), containing a very high number of MLL gene copies, shown by fluorescence in situ hybridization (FISH) analysis. Fibre-FISH experiments disclosed the presence of chromatin fibres with multiple MLL copies with a head-to-tail pattern. Apparently, no other region flanking the MLL site was present in the three der(11). MLL amplification was confirmed by the reverse transcription polymerase chain reaction (RT-PCR). The patient died 6 months after diagnosis, supporting the severe prognosis of sole MLL amplification. [source] | ||||||||||