Molecular characterization of variant translocations in chronic myelogenous leukemia.
Five to ten percent of the Ph-positive cases of chronic myelogenous leukemia (CML), termed variant translocations, involve at least one chromosome in addition to 9 and 22 in the abnormality. The involvement of chromosome 9 band q34, where the c-abl oncogene has been localized, is not always cytogenetically detectable in so called variant translocations due to complex rearrangements. We present two cases having the most frequently involved chromosomes (#3 and #17) in such translocations. In one case, both chromosome 9's were cytogenetically normal while in the other, band 9q34 was so called 'masked' or 'hidden'. After molecular evaluation using in situ hybridization and Southern blotting techniques, the involvement of the altered bcr/abl gene was demonstrated and the cytogenetic analysis was revised. Utilization of molecular probes in the evaluation of such cases should become a routine diagnostic procedure in detecting the exchange of bcr and c-abl sequences.
Verma
R S
RS
Long Island College Hospital, SUNY Health Science Center, Brooklyn.
Macera
M J
MJ
Benn
P
P
Groffen
J
J
D000328:Adult; D005260:Female; D006801:Humans; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000209:etiology / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D011505:Protein-Tyrosine Kinases; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D016315:Proto-Oncogene Proteins c-abl; D051562:Proto-Oncogene Proteins c-bcr; D011519:Proto-Oncogenes; D014178:Translocation, Genetic
D011518:Proto-Oncogene Proteins; D011505:Protein-Tyrosine Kinases; D016315:Proto-Oncogene Proteins c-abl; C496613:BCR protein, human; D051562:Proto-Oncogene Proteins c-bcr