Correlation between cell morphology and expression of the AML1/ETO chimeric transcript in patients with acute myeloid leukemia without the t(8;21).
The 8;21 chromosomal translocation involves the AML1 gene on chromosome 21 and the ETO gene on chromosome 8 and results in the transcription of a chimeric message. This translocation is most often associated with acute myelogenous leukemia with maturation (AML-M2). The leukemic cells of patients carrying t(8;21) often exhibit several characteristic morphologic features. We identified four cases in which the morphology led us to suspect a t(8;21), but in which this translocation was not observed by cytogenetic analysis. In two of the four cases, an AML1/ETO chimeric fragment was detected by reverse transcription and polymerase chain reaction (RT-PCR), and its sequence was found to be identical to that from patients with a cytogenetically proved t(8;21). Marrow specimens of the four patients lacking the t(8;21) cytogenetically were reviewed retrospectively with regard to seven morphologic features commonly reported to be associated with this translocation, and the results were compared to 13 morphologic controls with the t(8;21). Although none of the 13 controls had all of the characteristic morphologic features, all had at least six, as did the two t(8;21)-negative but RT-PCR-positive patients. The two patients who lacked the t(8;21) and who were RT-PCR-negative showed only three and four of these morphologic features, respectively. Both of the RT-PCR-positive patients had deletions of the long arm of chromosome 9, a common change associated with a t(8;21), supporting our assessment of these patients as having a cytogenetically undetected t(8;21).
Nucifora
G
G
Department of Medicine, University of Chicago, IL 60637.
Dickstein
J I
JI
Torbenson
V
V
Roulston
D
D
Rowley
J D
JD
Vardiman
J W
JW
D001483:Base Sequence; D015139:Blotting, Southern; D002891:Chromosomes, Human, Pair 21; D002898:Chromosomes, Human, Pair 8; D005260:Female; D015870:Gene Expression; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D015470:Leukemia, Myeloid, Acute / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D008297:Male; D008969:Molecular Sequence Data; D015514:Oncogene Proteins, Fusion / Q000235:genetics*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000032:analysis; D012194:RNA-Directed DNA Polymerase; D012189:Retrospective Studies; D014178:Translocation, Genetic
D015514:Oncogene Proteins, Fusion; D012333:RNA, Messenger; D012194:RNA-Directed DNA Polymerase