Clonal evolution with isodicentric Ph1 chromosome in Ph1-positive CML: Karyotypic conversion after bone marrow transplantation

Abstract

Clonal chromosomal evolution was observed in a 16-year-old boy suffering from Ph1-positive CML. An isodicentric Ph1 chromosome appeared 20 weeks after the initial diagnosis. At that time an allogeneic bone marrow transplantation was performed. Thereafter, during an observation period of more than 13 months, chromosome analyses showed neither the Ph1 chromosome nor the abnormal isodicentric variant. Close cytogenetic monitoring is suggested to reveal early unfavorable prognostic signs of the onset of blast crisis before it becomes evident in the bone marrow morphology.

Co-existence of isodicentric Ph chromosomes and the three-way Ph chromosome variant t(3;9;22)(p21;q34;q11) in a rare case of chronic myeloid leukemia

“…In the Mitelman database and the recent literature, there have been reports of 11 patients with CML and one patient with acute lymphoblastic leukemia that possess idic(Ph) chromosomes (26)(27)(28)(29)(30)(31). In nearly all cases, these idic(Ph) chromosomes formed by fusion at the satellite region in 22p13 (27)(28)(29). In the present case, two previous cases of CML (30,31) and the single case with acute lymphoblastic leukemia (26), idic(Ph) chromosomes formed by fusion at 22q11.…”

“…First reported in 1973 (25), idic(Ph) is a rare cytogenetic aberration in which two identical Ph chromosomes fuse while retaining their centromeres. In the Mitelman database and the recent literature, there have been reports of 11 patients with CML and one patient with acute lymphoblastic leukemia that possess idic(Ph) chromosomes (26)(27)(28)(29)(30)(31). In nearly all cases, these idic(Ph) chromosomes formed by fusion at the satellite region in 22p13 (27)(28)(29).…”

Isodicentric Philadelphia Chromosome: A Rare Chromosomal Aberration in Imatinib-Resistant Chronic Myelogenous Leukemia Patients - Case Report with Review of the Literature

“…Gene amplification and genomic heterogeneity are known to be associated with drug resistance [Campbell et al, 2002;Hochhaus and Hughes, 2004]. This amplification of genes activated in the Ph chromosome led to a growth advantage of leukemic cells, which in turn, results in an adverse clinical evolution with poor prognosis [Becher et al, 1984].…”