title: Association of a chromosomal 3;21 translocation with the blast phase of chronic myelogenous leukemia.
abstract: An identical reciprocal translocation between the long arms of chromosomes 3 and 21 with breakpoints in bands 3q26 and 21q22, t(3;21)(q26;q22), was found in three male patients with the blast phase of chronic myelogenous leukemia (CML). The abnormality was clonal in all three patients and was always accompanied by either a standard or variant 9;22 translocation resulting in a Philadelphia chromosome (Ph1). In two cases, the t(3;21) was the only abnormality other than a t(9;22) in the primary clone. Serial studies of one patient demonstrated that the t(3;21) occurred as a result of clonal evolution near the time of development of the blast phase. We have not observed the t(3;21) in greater than 500 patients with CML in the chronic phase. Thus, the t(3;21) is a new recurring cytogenetic abnormality associated with the blast phase of CML.
mesh_terms: D000328:Adult; D001752:Blast Crisis / Q000235:genetics*; D001853:Bone Marrow / Q000473:pathology; D002478:Cells, Cultured; D002869:Chromosome Aberrations; D025063:Chromosome Disorders; D002891:Chromosomes, Human, Pair 21; D002893:Chromosomes, Human, Pair 3; D006801:Humans; D007621:Karyotyping; D007951:Leukemia, Myeloid / Q000097:blood / Q000235:genetics* / Q000473:pathology; D007962:Leukocytes / Q000166:cytology; D008297:Male; D008677:Metaphase; D014178:Translocation, Genetic