Identification of Additional Cytogenetic Abnormalities in Chronic Myeloid Leukemia Cases with t (9;22) Chromosome Translocations

Abstract

Objective: The objective of this study is to detect additional simple and complex variant translocations with t(9;22) in chronic myeloid leukemia patients.

Methodology: This retrospective cross-sectional study was conducted at the hem-oncology department of Dr. Ruth K. M. Pfau Hospital in Karachi. It comprised data from patients between 2015 and 2023. Criteria for the study involved patients diagnosed with CML through blood count, bone marrow biopsy, and cytogenetic or molecular biology, showing additional chromosomal abnormalities, whether they are inpatients or outpatients of chronic myeloid leukemia.

Results: A total of 88 patients were Philadelphia-positive CML, out of which 53 (60.2%) were males & 35 (39.7%) were females. The mean age was 48 yrs ± 11.43. The group of 9 (10.2%) patients who harbor these complex variant translocations are comprised of 4 males and 5 females; the age range of these patients at diagnosis is from 32 to 66 yrs. All the patients were in the chronic phase at presentation. Chromosomal study in CML patients reveals 9 variant translocations with t(9;22)(q34;q11). These three-way variant defects/translocations were observed as 1p13, 1q21, 1p22, 2q31, 3q21, 3p21, 11q13, 15q24, and Xp11.2.

Conclusion: In our study, 9 patients had complex variants of t (9;22). These complex variants at diagnosis and during the TKI treatment may announce treatment failure and/or transformation into an advanced stage (accelerated or blast).

Keywords: Philadelphia chromosome, Three-way variant translocations, t(9;22)(q34;q11)