Interphase fluorescence in situ hybridization studies for the detection of 9q34 deletions in chronic myelogenous leukemia: a practical approach to clinical diagnosis.
Chronic myelogenous leukemia (CML) is characterized by the Philadelphia chromosome (Ph) in more than 90% of cases. Recent studies using fluorescence in situ hybridization (FISH) have shown that in a subset of patients with CML, deletions of 9q34 involving the argininosuccinate synthetase region occur at the time of the Philadelphia translocation and are associated with a poor prognosis. We performed interphase FISH studies in 152 cases of CML using a dual-color, dual-fusion probe system with a third probe directed at 9q34. Cytogenetic studies showed a simple (typical) Ph in 124/152 (82%), a cryptic Ph in 11/152 (7%), and a variant Ph chromosome with a complex translocation in 17/152 (11%) of cases. Interphase FISH studies showed single BCR/ABL fusion patterns in 48/152 (32%) of cases. Deletions of 9q34 were observed in 14% of all the cases and were present in 46% of cases with single BCR/ABL fusion pattern. All the 9q34 deletions occurred in cases with single BCR/ABL fusion signal. However, a single-fusion pattern is not specific for 9q34 deletions, and cases should be routinely screened for the presence of this prognostically significant abnormality by using a third probe directed specifically at 9q34.
Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha 68198, USA. paoun@unmc.edu
Patricia
P
Aoun
Michele
M
Wiggins
Diane
D
Pickering
James
J
Foran
Husain
H
Rasheed
Steve Z
SZ
Pavletic
Warren
W
Sanger
D002871:Chromosome Banding; D002872:Chromosome Deletion; D002899:Chromosomes, Human, Pair 9; D015342:DNA Probes; D016044:Fusion Proteins, bcr-abl; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods*; D007399:Interphase; D007621:Karyotyping; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000175:diagnosis* / Q000235:genetics*; D010677:Philadelphia Chromosome
D015342:DNA Probes; D016044:Fusion Proteins, bcr-abl