Cytogenetic and Fluorescence in situ Hybridization Profile of Pediatric Acute Lymphoblastic Leukemia in a University Hospital in South India

Abstract

Objective: The purpose of this study was to evaluate the cytogenetic and fluorescent in situ hybridization (FISH) profile in children with acute lymphoblastic leukemia (ALL), referred to a university hospital in a 5-year 6-month period. Subjects and Methods: Cytogenetic analysis of the bone marrow aspirate specimens of 91 patients was performed by standard Giemsa (G)-banding and interphase FISH (iFISH). Results: The frequency of chromosomal abnormalities detected by G-banding was 29.5%, and the frequency of nonrandom abnormalities with independent prognostic significance identified by iFISH was 46.4%. The abnormality with the highest frequency was gain of RUNX1 (n = 18, 21.4%), followed by ETV6/RUNX1 fusion (n = 7, 8.3%), and gain of KMT2A (n = 6, 7.1%). Additionally, rarely reported gains of ETV6, PBX1, and ABL1 were observed at a frequency of 6% (n = 5), and the deletion of ETV6 and TCF3 was seen at a frequency of 3.6% (n = 3) and 2.3% (n = 2), respectively. A 10-year old with intrachromosomal amplification of chromosome 21 was also observed. Conclusions: This study strengthens and widens the current knowledge of the cytogenetic landscape of pediatric ALL.