Some observations on fluorescence in situ hybridization evaluation of chronic myelocytic leukemia.
Cosmid probes specific for the major BCR/ABL rearrangement (commercially available probes) were employed by us to evaluate 134 patients with the clinical diagnosis of chronic myelocytic leukemia (CML). The following represent our main observations: 1) No significant statistical difference regarding a false positive fusion signal was seen in the distribution pattern between the Ph negative (-) cases (110) and the normal controls (3.23 +/- 1.97 vs 2.8 +/- 1.92, respectively). 2) The mean percentage of cells with a positive fusion signal in the Ph positive (+) CML cases at presentation was 70 +/- 12.3 in bone marrow samples (12 cases) and 45 +/- 12.4 in blood samples (3 cases). 3) A significant discrepancy was seen between the interphase FISH and cytogenetics data in the monitoring of four out of eight patients post-therapy. The clinical significance of this observation needs to be clarified. 4) Three Ph(-) patients with significant leukocytosis had closely adjacent but not fused signals (20%, 16%, and 20% of cells, respectively, vs. the control: 4%). This may indicate a temporal and spatial association between chromosomes 9 and 22 prior to the BCR/ABL rearrangement (Ph chromosome formation).
Chen
Z
Z
Genzyme Genetics, Santa Fe, NM 87505, USA.
Notohamiprodjo
M
M
Richards
P D
PD
Lane
F B
FB
Morgan
R
R
Stone
J F
JF
Sandberg
A A
AA
D000368:Aged; D015342:DNA Probes; D005260:Female; D016044:Fusion Proteins, bcr-abl / Q000235:genetics*; D015321:Gene Rearrangement; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000235:genetics*; D008297:Male
D015342:DNA Probes; D016044:Fusion Proteins, bcr-abl