Together, our results demonstrate that there is a masked t(8;21) translocation in AML that is not detectable by cytogenetic analysis but is able to transcribe an AML1/ETO fusion transcript similar to that transcribed in t(8;21)-positive AML-M2 patients.
An AML1/ETO fusion transcript is consistently detected by RNA-based polymerase chain reaction in acute myelogenous leukemia containing the (8;21)(q22;q22) translocation.
We also used the polymerase chain reaction (PCR) with appropriate primers from the AML1 and ETO genes to amplify the cDNAs from a cell line with the t(8;21) and from seven AML patients with the t(8;21).
The t(8;21) translocation is one of the most frequent chromosomal abnormalities in acute myeloid leukaemia and results in gene fusion between AML1 on chromosome 21 and MTG8 (= ETO or CDR) on chromosome 8.
The translocation from chromosome 8 to chromosome 21, t(8;21), associated with acute myeloid leukemia results in production of an AML1/MTG8(ETO) fusion transcript.
While this finding raises interesting questions about the biology of acute leukemia, it limits the value of the AML/ETO RT-PCR for the prediction of impending relapse.
t(8;21)(q22;q22), found in acute myeloid leukemia (AML) and occasionally in myelodysplasia (MDS), results in the fusion of the AML1 gene on 22q22 to the ETO gene on 8q22, generating a chimeric AML1/ETO transcript, which is a molecular marker of the translocation.
Using a qualitative RT-PCR method, AML1/ETO transcripts could be detected in all samples from 15 first PBSC harvests and 11 second PBSC harvests obtained from 15 patients with t(8;21) AML.
Polyclonal haemopoieses associated with long-term persistence of the AML1-ETO transcript in patients with FAB M2 acute myeloid leukaemia in continous clinical remission.
The AML-1/ETO fusion protein is created by the (8;21) translocation, the second most frequent chromosomal abnormality associated with acute myeloid leukemia.
In t(8;21) acute myelogenous leukemia (AML), the AML1 gene is juxtaposed to the ETO gene located on chromosome 8, generating an AML1/ETO fusion protein.
The former type is associated with the chromosomal translocations found in acute myeloid leukemia, such as the AML1/MTG8 in t(8;21) and PML/RAR alpha in t(15;17).