Fluorescence in situ hybridization provides evidence for two-step rearrangement in a masked Ph chromosome formation.
A chronic myelogenous leukemia (CML) patient with a masked Ph chromosome due to the translocation (9;10;22)(q34;q24;q11) is reported. Banding analysis showed a 9q+ chromosome typical of standard t(9;22)(q34;q11), and fluorescence in situ hybridization studies confirmed the involvement of a chromosome 10 in the masked Ph formation and also the presence of 3' ABL-DNA sequences in the der(22). This complex rearrangement could be explained by two consecutive translocations: the first, a standard t(9;22) (q34;q11), the second, a translocation between a chromosome 10 and the der(22) with a breakpoint in sequences derived from chromosome 9 telomeric to the ABL gene. By reverse transcription polymerase chain reaction (RT-PCR), we studied the BCR/ABL transcript junction: a chimeric m-RNA b3-a2, indicating a breakpoint within the major breakpoint cluster region, was found.
Sessarego
M
M
Dipartimento di Medicina Interna, Università di Genova, Italy.
Fugazza
G
G
Canepa
L
L
Bacigalupo
A
A
Bruzzone
R
R
Patrone
F
F
D000328:Adult; D002873:Chromosome Fragility; D002879:Chromosomes, Human, Pair 10; D002892:Chromosomes, Human, Pair 22; D002899:Chromosomes, Human, Pair 9; D005260:Female; D015321:Gene Rearrangement; D016313:Genes, abl; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000235:genetics*; D005810:Multigene Family; D010677:Philadelphia Chromosome; D016133:Polymerase Chain Reaction; D014178:Translocation, Genetic