ISSN:
1569-8041
Keywords:
chronic myelogenous leukemia
;
FISH
;
fluorourescent in situ hybridization
;
Philadelphia chromosome negative
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract Background: In 5%–10% of patients with of chronic myelogenous leukemia (CML), the Philadelphia chromosome (Ph) is not identified, despite the presence of the associated BCR–ABL molecular abnormality (Ph-negative, BCR–ABL-positive CML) because of sub-microscopic rearrangements. Patients and methods: Six patients with Ph-negative, BCR–ABL-positive CML were investigated. The Ph chromosome detection via fluorescence in situ hybridization after 24-hour mitotic arrest of bone marrow cultures resulting in several hundreds of metaphases (hypermetaphase FISH or HMF) was useful in explaining the nature of the six cases. Results: Four patients had a low frequency of Ph-positive cells by HMF (5.7%, 4.8%, 3.9%, 0.2%), i.e., a typical Ph translocation. However, two cases involved a 9q34 inserted into chromosome 22q11 (74.2% and 92%), without a deletion from chromosome 22 and reciprocal translocation onto 9, i.e., not a typical Ph translocation. The pattern of UBCR gene rearrangement was characterized by the same genomic recombination of 5′-BCR and c-ABL, both in the four cases of typical translocation (9;22) and in the two cases of insertion of 9q34 into chromosome 22q11. Conclusions: The HMF identified two different bases for Ph-negative, BCR–ABL-positive cells in CML – presence of low frequency of cells with typical Ph translocations or presence of cells with ABL insertions into the BCR gene on chromosome 22.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1008349405763
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