Impact of sex chromosome abnormalities in male chronic myeloid leukemia patients

Abstract

Introduction

Chronic Myeloid Leukemia (CML) is a myeloproliferative disorder characterized by the Philadelphia chromosome (Ph) resulting from the reciprocal translocation t(9;22)(q34;q11). Sex chromosomal abnormalities are found rarely in CML patients.

Materials and methods

Conventional and molecular cytogenetic analysis (Fluorescent In Situ Hybridization (FISH)) were performed to reveal the presence of Ph and additional chromosomal abnormalities (ACA).

Results

Three patients with abnormalities within sex chromosomes, one Klinefelter syndrome (KS) patient and two cases with LOY (Loss of Y) diagnosed with CML CP were included in the study. All three patients initially responded to the targeted therapy, became resistant to their treatment course and switched to 2nd line therapies. In the 15th month, the KS patient abruptly turned into BC and showed clonal evolution with four karyotypic patterns. According to Mitelman databases, this is the first KS-CML patient who showed three major route abnormalities, +8, i(17) and + der(22) in a single clone. Survival analysis showed one patient with LOY chromosome expired on the 48th month of diagnosis.

Conclusion

The application of cytogenetic techniques in identifying the constitutional abnormality of KS, ACA at initial CML diagnosis, revealing of extra Ph during the treatment course and clonal evolution in BC (Blast Crisis) assist the proper monitoring of disease transformation and serves as a major diagnostic tool for CML patients thereby switching the treatment protocols. A systematic stratification of patients according to the chromosomal abnormalities is needed in CML patients.