Deletions on der(9) chromosome in adult Ph-positive acute lymphoblastic leukemia occur with a frequency similar to that observed in chronic myeloid leukemia.
The t(9;22)(q34;q11), generating the Philadelphia chromosome (Ph), is found in more than 90% of patients with chronic myeloid leukemia (CML) and in 15-30% of adults with acute lymphoblastic leukemia (ALL). Different groups have recently described the presence of large genomic deletions adjacent to the translocation breakpoint on the derivative chromosome 9 in 9-16% of CML patients. In the present paper, we report a FISH study of 45 Ph+ adult ALL patients with the aim of investigating the presence of deletions on derivative chromosome 9. In four (9%) of 45 cases, all showing an M-bcr, we detected deletions on der(9). The frequency of deletions we observed is similar to that reported in CML patients. The association of an M-bcr breakpoint and deletions appears significant (P=0.03). Some authors have suggested a very low incidence of der(9) deletions in ALL. This discrepancy can be explained by taking into account the low percentage of M-bcr ALL patients in the latter study (18%) compared to the present one (44%).
Specchia
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Department of Hematology, University of Bari, Italy.
Albano
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F
Anelli
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L
Storlazzi
C T
CT
Zagaria
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A
Mancini
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M
Cuneo
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A
Pane
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F
Foà
R
R
Manolelli
F
F
Liso
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Rocchi
M
M
D000328:Adult; D002872:Chromosome Deletion; D002899:Chromosomes, Human, Pair 9; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000235:genetics; D008297:Male; D008875:Middle Aged; D015513:Oncogene Proteins / Q000235:genetics; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics*; D011505:Protein-Tyrosine Kinases; D011518:Proto-Oncogene Proteins; D051562:Proto-Oncogene Proteins c-bcr; D017384:Sequence Deletion
D015513:Oncogene Proteins; D011518:Proto-Oncogene Proteins; D011505:Protein-Tyrosine Kinases; C496613:BCR protein, human; D051562:Proto-Oncogene Proteins c-bcr