The value of reverse banding in detecting bone marrow chromosomal abnormalities: translocation between chromosomes 1, 9, and 22 in a case of chronic myelogenous leukemia (CML).

A case of chronic myelogenous leukemia (CML) with complex chromosomal abnormalities is reported. Conventional staining techniques indicated incorrectly that the Ph1 chromosome was not present. These studies showed a 46,XY,-1,+C karyotype in all bone marrow cells. Employing RFA (R bands by fluorescence using acridine orange) technique it was clear that the part of the long arm of chromosome 1 (1q23 leads to qter) was missing the tip of the long arm chromosome 22 (band q22) was translocated to it. The missing long arm of chromosome 1 was translocated to the long arm of chromosome 9. Furthermore, there was a break at band 9q22 and the whole terminal part was lost. The value of RFA technique is discussed.