Chromosome-1 abnormalities in Childhood B-Lymphoblastic Leukemia - An analysis with reference to clinical variables and survival outcome

Neelum Mansoor; Naila Rafiq; Saba Jamal; Aamir Ehsan

doi:10.12669/pjms.40.2(ICON).8946

Chromosome-1 abnormalities in Childhood B-Lymphoblastic Leukemia - An analysis with reference to clinical variables and survival outcome

Pak J Med Sci. 2024 Jan;40(2ICON Suppl):S47-S52. doi: 10.12669/pjms.40.2(ICON).8946.

Authors

Neelum Mansoor¹, Naila Rafiq², Saba Jamal³, Aamir Ehsan⁴

Affiliations

¹ Neelum Mansoor, FCPS. Section Head Cytogenetics, Indus Hospital and Health Network, Karachi, Pakistan.
² Naila Rafiq, FCPS. Consultant Pediatric Hematology-Oncology, Indus Hospital and Health Network, Karachi, Pakistan.
³ Saba Jamal, Diplomate American Board of Anatomic and Clinical Pathology, Diplomate American Board of Hematology, Senior Director Pathology and Blood Transfusion Services, Indus Hospital and Health Network, Karachi, Pakistan.
⁴ Aamir Ehsan, MD. Medical Director, CorePath Laboratories, San Antonio, Texas, USA.

Abstract

Background: Chromosome-1 abnormalities (C1As) are common genetic aberrations in hematological malignancies. We sought to evaluate significance of these abnormalities with reference to clinical characteristics and survival outcome in a pediatric B-Lymphoblastic Leukemia (B-ALL) cohort.

Methods: This is a retrospective study conducted in cytogenetic section of Indus Hospital and Health Network. Data was retrieved from October 2020 to July 2022 for childhood B-ALL cases exhibiting C1As. Chromosome analysis was performed on Cytovision MB8 using G-banded metaphases derived from unstimulated bone marrow culture. Results were recorded according to the International System for Human Cytogenetic Nomenclature (ISCN-2020). Data analyzed using SPSS, version 24.0.

Results: C1As were observed in 60/450 (13.3%) cases of B-ALL. Among C1As, 29 (48%) cases had t(1;19). There were 13 (45%) balanced and 16 (55%) unbalanced translocations. The aberrations without t(1;19) were seen in 31 (52%) cases including 1q duplication with hyperdiploidy in 14 (45%) cases. The median age for C1As with and without t(1;19) was eight years and six years while the median leukocyte count was 32 x 10⁹/L vs. 17 x 10⁹/L. Event-free survival (EFS) for cases with and without t(1;19) was 69% and 74.2% respectively.

Conclusion: Despite the fact that the t(1;19) positive group had a higher median age, a higher white cell count and more CNS positives, the difference in EFS is statistically insignificant when compared to the t(1;19) negative cases. Furthermore, we found a survival difference between balanced and unbalanced t(1;19) groups, which is statistically insignificant but warrants large-scale prospective studies for further understanding.

Keywords: Chromosomal aberrations; Chromosome 1; Cytogenetics; Leukemia; Survival outcome.