Studies of complex Ph translocations in cases with chronic myelogenous leukemia and one with acute lymphoblastic leukemia.
The BCR/ABL gene fusion, the hallmark of chronic myelogenous leukemia (CML) is generated in 2-10% of patients by a variant Ph translocation involving 9q34, 22q11.2, and one or more additional genomic regions. The objective of this study was the characterization by conventional and molecular cytogenetics of complex variant Ph translocations present at diagnosis. FISH studies were performed in 7 cases using the LSI BCR/ABL ES probe allowing the detection of the fusion BCR/ABL gene on the Ph chromosome in all of them and 9q34 deletions in 2 cases. Three cryptic complex rearrangements were detected by FISH studies. The third and the fourth chromosome regions involved in the 8 complex variant translocations were: 1q21, 1p36, 5q31, 11q13, 12q13, 12p13, and 20q12. In conclusion, FISH studies have been useful in the detection of the BCR/ABL rearrangements and 9q34 deletions, and to identify complex rearrangements that differ from the ones previously established by conventional cytogenetics.
Costa
Dolors
D
Hematopathology Unit, Hospital Clínic. Villarroel, 170, 08036, Barcelona, Catalonia, Spain. dcosta@clinic.ub.es
Carrió
Ana
A
Madrigal
Irene
I
Arias
Amparo
A
Valera
Alexandra
A
Colomer
Dolors
D
Aguilar
Josep Lluís
JL
Teixido
Montse
M
Camós
Mireia
M
Cervantes
Francisco
F
Campo
Elías
E
D000328:Adult; D002871:Chromosome Banding; D002872:Chromosome Deletion; D002899:Chromosomes, Human, Pair 9 / Q000235:genetics; D020732:Cytogenetic Analysis; D005260:Female; D016044:Fusion Proteins, bcr-abl / Q000235:genetics; D015321:Gene Rearrangement; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D010677:Philadelphia Chromosome; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics*; D014178:Translocation, Genetic
D016044:Fusion Proteins, bcr-abl