A complex translocation t(5;9;22) in Philadelphia cells involving the short arm of chromosome 5 in a case of chronic myelogenous leukemia.

Chronic myelogenous leukemia (CML) is genetically characterized by the reciprocal translocation of chromosome 9 and 22, t(9;22)(q34;q11) which results in the fusion of BCR/ABL gene observed on the derivative chromosome 22 called Philadelphia (Ph') chromosome. About 5-8% of Philadelphia positive patients with CML show various complex translocations involving one or more other chromosomes, in addition to chromosome 9 and 22. In our report we discuss one case with CML, his cytogenetic study revealed a complex translocation t(5;9;22)(p15.1; q34; q11.2), del 5p15.1-->pter, translocation BCR(22q11.2-->qter) to der(5), positive Ph-chromosome and positive t(BCR\ABL). Further confirmation of complex translocation was done by FISH study using the LSI BCR/ABL dual color dual fusion (DF) translocation probe, chromosome 5 and 22 whole paint probes.