Chromosome banding studies in 106 cases of chronic myelogenous leukemia

Summary Chromosome banding studies performed on 106 cases of CML in Sapporo revealed that 101 (95.3%) were Ph 1 -positive, and 5 (4.7%) Ph 1 -negative, the latter including a case of juvenile type CML. Of the 101 Ph 1 -positive patients, 98 showed the standard type Ph 1 translocation, t(9;22)(q34;q11), while the remaining 3 had a complex Ph 1 translocation as represented by t(4;9;22), t(9;14;22), or t(9;10;15;19;22). There were 28 patients who showed other chromosome changes in addition to the Ph 1 translocation. Trisomy 8, duplication of Ph 1 , isochromosome 17q, and trisomy 19 were most frequently involved in the additional changes, and 2 or more of them often participated in the major routes of karyotypic evolution. Other additional changes observed were 6 translocations, 4 partial deletions, 2 partial trisomies for 1q, trisomies 6, 7, 12, 15, and 21, a monosomy 5, a partial duplication of no. 9, a missing Y, and so on. The present cytogenetic findings were evaluated with respect to some of the clinical and therapeutic parameters.