BCR/ABL fusion gene detected on 9q34 by fluorescence in situ hybridization in an acute leukemia with two BCR/ABL positive clones, one Ph-negative and one Ph-positive.
We report cytogenetic, fluorescence in situ hybridization (FISH), and molecular analyses in the first reported case of an acute leukemia with two BCR-positive clones: one cell Ph-positive and all others Ph-negative. A BCR/ABL fusion gene on 9q34 was detected only with a BCR/ABL dual color translocation probe. These FISH interphase signals must be confirmed on a metaphase to avoid an erroneous interpretation. This observation appears to indicate a 2-step mechanism for this aberrant fusion gene localization: first, a classical t(9;22), and then the transfer of the fusion gene formed on chromosome 22 to chromosome 9 by a second translocation between the long arms of the derivative chromosomes 9q+ and 22q-, masking the first chromosome exchange.
Terré
C
C
Laboratory of Biochemistry, Genetics and Hematology, Hôpital de Versailles, Versailles, France.
Bastie
J N
JN
Garcia
I
I
Suzan
F
F
Cayuela
J M
JM
Therond
P
P
Castaigne
S
S
D000208:Acute Disease; D002892:Chromosomes, Human, Pair 22 / Q000235:genetics*; D002899:Chromosomes, Human, Pair 9 / Q000235:genetics*; D002999:Clone Cells / Q000473:pathology; D005260:Female; D016044:Fusion Proteins, bcr-abl / Q000235:genetics*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000235:genetics*; D008875:Middle Aged; D010677:Philadelphia Chromosome; D020133:Reverse Transcriptase Polymerase Chain Reaction
D016044:Fusion Proteins, bcr-abl