t(8;21;8)(p23;q22;q22): A new variant form of t(8;21) translocation in acute myeloblastic leukemia with maturation

The complex variants of t(8;21) involving chromosomes 8 and 21 as well as a variable chromosome account for 1.1 similar to5% of acute myeloid leukemia (AML) patients. This paper reports a case of AML-M2 with t(8;21;(8) over b ar) translocation for the first time. The patient was a female, aged 47 yea rs. Her myelogram was compatible with AML-M2. Chromosome study using R-band ing technique revealed a karyotype 46, XX, t(8;a)(p23;q22). Dual-color FISH assay with two probes P1 164(green signal) and YAC 225B8 (red signal) both of which closely located on the 8q showed that one yellow signal consistin g of a green signal and a red signal and one red signal appeared on the lon g and the short arm of the same der(8) chromosome, respectively, further co nfirming this translocation occurred between both homologous chromosomes 8. RT-PCR analysis detected the AML1/ETO fusion transcript in our patient, th us indicating that this chromosomal aberration was, in fact, a complex thre e-way rearrangement t(8;21;(8) over bar)(p23;q22;q22). In conclusion, combi ning conventional karyotype, FISH or RT-PCR analyses is a rational strategy for identification of the complex variants of t(8;21) translocation.