Chronic myelogenous leukemia with an unusual karyotype: 46,XY,t(17q +; 22q-)

Genomic diversity of Philadelphia-positive chronic myelogenous leukemia

The incidence of breakpoints in CML patients with variant translocations was investigated. There was no relationship between the length of various chromosomes with breakpoint frequency. However, a significantly higher (p less than 0.05) incidence of breaks were seen on the long arms as compared to the short arms due mainly to the involvement of 9q and 22q in these translocations. Chromosome 17 showed a significantly (p less than 0.005) higher involvement in these translocations, however only when 9q34-qter was not cytogenetically involved. A total of 683 breaks were found in 225 cases. 362 of these were located at c-abl and c-sis, while 110 were at other oncogenetic sites. The prognostic and hematologic features of patients with variant translocations are not significantly different from those of CML cases with the typical 9q;22q translocation. Some of these complex translocation, where the breakpoints are correlated with oncogenetic sites, are further discussed in molecular terms.

New types of unusual and complex Philadelphia chromosome (Ph1) translocations in chronic myeloid leukemia

Nine cases of Philadelphia chromosome-positive chronic myeloid leukemia with an aberrant translocation are reported. In three cases an unusual translocation was found, the recipient chromosome being Nos. 14, 17, and 18, respectively. In six cases the translocation involved a third chromosome in addition to Nos. 9 and 22: there were two cases involving chromosome No. 1, two involving chromosome No. 14, one involving chromosome No. 3, and one involving chromosome No. 12. The clinical significance of the aberrant translocations and the translocation mechanism is discussed.