A new translocation involving chromosomes 8 and 9 in a Philadelphia-negative chronic myelogenous leukemia

Chronic myeloid leukemia with complex karyotypes: Prognosis and therapeutic approaches

OBJECTIVE AND BACKGROUND

Chronic myeloid leukemia (CML) is a neoplastic disease whose genetic and cytogenetic changes play important roles in prognosis and treatment strategies. Philadelphia (Ph) translocation t(9;22)(q34;q11) is a diagnostic and prognostic biomarker in CML.

METHODS

Pubmed and Google Scholar databases were searched for English language articles from 1975 to 2017 containing the terms CML; Additional chromosomal abnormalities; Philadelphia translocation; Prognosis; and Treatment.

DISCUSSION

Approximately 10-12% of CML patients exhibit additional chromosomal aberrations (ACAs) in chronic phase and blast crisis. ACAs emergence may cause different features in CML patients according to Ph pattern. For instance, deletion of chromosome 9 derivation is associated to patient's bad survival, whereas monosomy 7 develops myeloid dysplastic syndrome (MDS) or acute myeloid leukemia (AML) in CML patients with Ph-negative pattern. And ACAs in Ph-positive CML is considered as a failure in the management of CML with imatinib.

CONCLUSION

CML classification using different features such as Ph and ACAs can play a decisive role in the evaluation of treatment responses in patients, for example, CML patients with Ph negative and monosomy 7 develop MDS or CML patient -Y and extra copy of Ph have a good response to tyrosine kinase inhibitors, therefore, classifications according to Ph and ACAs play an important role in choosing better treatment protocols and therapeutic strategies. Karyotype analysis in CML patients with complex karyotype shows unrandom pattern so ACAs can be great clue in medical guidelines.

Blast crisis of chronic myeloid leukemia: diagnosis prompted by T(8;9)

T(8;9) is a relatively new translocation that has been reported in a few patients with chronic myeloid leukemia (CML) but never in acute myeloid leukemia (AML). We report here a patient who presented with AML with t(8; 9). He lacked the Philadelphia chromosome but tested positive for the gene by the polymerase chain reaction method. This confirmed the diagnosis of CML with blast crisis, and appropriate treatment could be instituted

Translocation t(9;9)(p13;q34) in Philadelphia-negative chronic myeloid leukemia with breakpoint cluster region rearrangement

Chromosome analysis showed a t(9;9)(p13;q34) in a patient with chronic myeloid leukemia (CML) without a Philadelphia (Ph) chromosome in all examined cells. Southern blot analysis of leukocyte DNA revealed rearrangement of breakpoint cluster region (bcr) within the 5.8-kb bcr sequences as in Ph-positive CML patients. The findings confirm that the 9q34 and 22q11 bands are always involved in CML independent of the chromosomal evidence. It is suggested that Ph-negative bcr-positive CML may have variant translocations, as in the case of the t(9;9) reported here.