A unique case of complex variant translocation of t(6;9;22)(p22;q34;q11.2), der(19) in a newly diagnosed patient with chronic myeloid leukemia.

Chronic myeloid leukemia (CML) is a clonal myeloproliferative disorder characterized by the dysregulated production and uncontrolled proliferation of myeloid neoplastic cells. CML is associated with the fusion of BCR (on chromosome 22) and ABL1 (on chromosome 9) resulting in the BCR-ABL1 fusion gene. The translocation of chromosomes (9;22)(q34;p15) is present in almost 90-95% of patients with CML and only 5-8% CML patients have established variant complex translocation due to the participation of one or more chromosomes other than 9 and 22 chromosome. In the present study, a unique case of a pH chromosome-positive CML is reported with a new variant pH translocation involving three chromosomal aberrations 6p22, 9q34, 22q11.2 and derivation 19 which has not been described previously. The complex variant translocation with pH chromosome was 46,XY,t(6;9;22)(p22:q34;q11.2), der(19)[48]/46,XY[2]  in this newly diagnosed CML patient. Additional cytogenetic anomalies may be seen in patients which are not controlled by the tyrosine kinase inhibitor in CML patients or in accelerated/blastic phase. In this case, the patient' treatment was switched to dasatinib because the IS-NCN could not be controlled with imatinib. In conclusion, complex translocations in unusual locations of the BCR / ABL gene appear to indicate a poor prognosis.