Comparison of karyotype analysis and RT-PCR for AML1/ETO in 204 unselected patients with AML.
The chromosomal translocation t(8;21) (q22;q22) is often associated with acute myeloid leukemia with maturation (AML-M2) and can be detected by a reverse transcription-polymerase chain reaction (RT-PCR) for the AML1/ETO fusion mRNA. We investigated the prevalence of t(8;21) and AML1/ETO in 204 unselected patients with AML and compared the results of cytogenetic analysis with these of RT-PCR. Fifteen of 204 AML patients (7.4%) showed a t(8;21) in karyotype analysis. In 17 of 204 patients (8.3%) AML1/ETO was detected by RT-PCR. All patients who had a t(8;21) in conventional karyotyping also showed the gene rearrangement in molecular analysis, including one patient with a three-way translocation t(5;8;21). AML1/ETO was also detected in two AML patients lacking the t(8;21) cytogenetically. One had a normal diploid karyotype bone marrow (BM) at diagnosis; she has now been in CCR for 12 months. The second patient showed a complex chromosomal anomaly involving chromosome 21, but without a typical 8;21 translocation (BM in relapse). He died in relapse after an overall survival of 60 months. These data indicate that the results of karyotyping and RT-PCR are not completely identical, and molecular biology identifies approximately an additional 5-10% of AML1/ETO positive cases. The clinical relevance of our findings will have to be evaluated with larger patient numbers.
Mitterbauer
M
M
CCRI, St. Anna Children's Hospital, Vienna, Austria.
Kusec
R
R
Schwarzinger
I
I
Haas
O A
OA
Lechner
K
K
Jaeger
U
U
D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002891:Chromosomes, Human, Pair 21; D002898:Chromosomes, Human, Pair 8; D050676:Core Binding Factor Alpha 2 Subunit; D005260:Female; D006801:Humans; D007621:Karyotyping / Q000379:methods; D007951:Leukemia, Myeloid / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D015514:Oncogene Proteins, Fusion; D016133:Polymerase Chain Reaction / Q000379:methods; D000075142:RUNX1 Translocation Partner 1 Protein; D011993:Recombinant Fusion Proteins / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics*; D014178:Translocation, Genetic
C107844:AML1-ETO fusion protein, human; D050676:Core Binding Factor Alpha 2 Subunit; D015514:Oncogene Proteins, Fusion; D000075142:RUNX1 Translocation Partner 1 Protein; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors