Coexistence of Philadelphia chromosome positive cells with and without der(9) deletion in a patient with chronic myelogenous leukemia.
Recently, large deletions adjacent to the Philadelphia (Ph) translocation breakpoint on the derivative chromosome 9 have been reported to be found in a substantial number of patients with chronic myelogenous leukemia (CML). The existence of der(9) deletion is reported as a powerful indicator of a poor prognosis. So far, der(9) deletion is considered to be generated when the Ph translocation occurs, because when der(9) deletion is found, it is detected in all the Ph-positive (Ph+) cells of a particular CML patient. On FISH examination of 47 Vietnamese CML patients, we found 11 patients carrying der(9) deletion. Among these, two patients harbored Ph+ metaphase cells with der(9) deletion and also Ph+ cells without it. In CML patients with der(9) deletion, reportedly no ABL/BCR transcript is detected. In these two patients, the proportion of Ph+ cells without der(9) deletion was much smaller than that of the cells with der(9) deletion. Nevertheless, we detected a ABL/BCR (1b-b4) transcript in the two patients. This is further evidence for the existence of Ph+ cells without der(9) deletion. It is possible that in some CML patients, der(9) deletion is generated in the progression of the disease.
Xinh
Phan Thi
PT
Division of Ultrafine Structure, Department of Pathology, Research Institute of International Medical Center of Japan, Toyama 1-21-1, Shinjuku-ku, Tokyo 162-0052, Japan.
Vu
Hoang Anh
HA
Nghia
Huynh
H
Binh
Nguyen Tan
NT
Van Be
Tran
T
Van Binh
Tran
T
Tokunaga
Katsushi
K
Sato
Yuko
Y
D000328:Adult; D002869:Chromosome Aberrations; D002872:Chromosome Deletion; D016044:Fusion Proteins, bcr-abl / Q000235:genetics; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology*; D008297:Male; D008875:Middle Aged
D016044:Fusion Proteins, bcr-abl