Cytogenetic abnormalities in pediatric acute lymphoblastic leukemia- retrospective study from a tertiary care center in Eastern India

Acute leukemia accounts for 80 % of cancers in children. Factors affecting survival include access to treatment, nutritional status, and inherent risk factors for the disease, such as age, immunophenotyping, total leucocyte count, cytogenetics, and Measurable residual disease (MRD). There are limited data regarding cytogenetic abnormalities in leukemia cases in India compared to High Income Countries (HIC). To study the cytogenetic abnormalities and molecular genetic profile in acute leukemia patients diagnosed at our centre. A total of 57 children with acute lymphoblastic leukemia (ALL) diagnosed from July 2021- December 2023 and for whom cytogenetic reports were available, were included in the study. Data was retrospectively collected from medical records. Among 57 patients with ALL, a majority had normal karyotyping (n=25, 42 %) or non-analysable metaphases (n = 11, 20 %). Ten (20 %) had pseudodiploidy, 7 (11.7 %) had high hyperdiploidy, 2 (3.3 %) patients each had low hyperdiploidy and hypodiploidy. Out of 51 cases of B-cell ALL, 6 (11.7 %) cases had ETV6-RUNX1 fusion genes, which was the most common; four (7.8 %) cases had KMT2A translocations, two (3.9 %) cases each had TCF3 and BCR-ABL fusion genes. Novel chromosomal abnormalities in B-cell ALL were t(8;9)(q11.2;q24), t(7;13)(p13;q12) and t(15;18)(q22;p11.2). Cytogenetic and molecular profiling aided in prognosis and treatment decisions. ETV6-RUNX1 and hyperdiploidy were the most common favourable prognostic markers, but still underepresented compared to studies from HIC. The significance of rare fusion genes such as t(8;9), t(7;13), and t(15;18) in our sample is unknown. The small sample size and high rate of mortality and abandonment precluded meaningful outcome analysis.