Isodicentric Philadelphia chromosome: an uncommon chromosomal abnormality in the chronic phase of chronic myeloid leukemia (CML)

Abstract

Key Clinical MessageAn isodicentric Philadelphia chromosome is an uncommon finding previously described as a secondary chromosomal abnormality in accelerated‐ or blast‐phase of chronic myeloid leukemia (CML) with resistance to imatinib mesylate or dasatinib. Here, we present a case with idic(Ph) chromosome identified at initial diagnosis in a patient with chronic‐phase CML.

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

“…Reports of the ider(22) chromosome in CML-CP at the time of diagnosis is infrequent; only 3 cases have been reported, and these cases were associated with lack of hematological and cytogenetic response, even if administered with a higher dose of IM [Li Ming Chua et al, 2010;Vundinti et al, 2014;Loo et al, 2016]. However, in most of the CML cases so far reported, the emergence of ider (22) was associated with IM resistance or ider (22) appeared at the time of relapse or when the patients were in accelerated or blast crisis phases of CML [Mitelman et al, 1976;Pernice et al, 1993;Szych et al, 2007;Brahmbhatt et al, 2014].…”

“…The exact reason for the formation of ider (22) is unknown, but it is known that the occurrence of this genetic defect at any stage of CML is associated with genomic instability, poor prognosis, and a higher possibility of resistance to targeted therapy [Mitelman et al, 1976;Pernice et al, 1993;Szych et al, 2007;Li Ming Chua et al, 2010;Vundinti et al, 2014;Loo et al, 2016]. Therefore, occurrence of the ider(22) chromosome could be considered as an important marker correlated with aggressive progression of CML as well as the emergence of drugresistant cell clones.…”