t(12;21)(p13;q22) reciprocal translocation, AML1/ETO fusion gene
Translocation t(8;21)(q22;q22) involves the AML1 gene, also known as RUNX1, and gene ETO, and is one of the genetic alterations found more often in childhood acute myeloblastic leukemias (AML). The frequency of this alteration in the AML-M2 subtype approaches 40%. The AML1/ETO fusion gene transcript is detected in AML patients with t(8;21), and appears to play a critical role in establishing the leukemic clone. The t(8;21)(q22;q22) is commonly associated with additional chromosomal abnormalities such as loss of a sex chromosome and del(9q22). The expression of neural cell adhesion molecule CD56 appears to be an adverse prognostic indicator. The molecular characteristics of this rearrangement force to make screening rearrangement using FISH (fast and reliable) or the detection of the fusion transcript (mRNA) by RT-PCR (most painstaking and sensitive method to degradation ), which by high specificity is useful for both the diagnosis and monitoring residual disease in this condition.
AML patients carrying t(8;21)(q22;q22) are associate with a good response to chemotherapy and a high rate of complete remission with long-term survival when high-dose cytarabine treatment is administered in the post-remission phase.
References
- Al-Bahar S, et al. (2008) Gulf J Oncolog. (3):9-15.
- Raspadori D, et al. (2001) Leukemia 15 (8): 1161-4.
