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

Abstract

<b><i>Objective:</i></b> 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. <b><i>Subjects and Methods:</i></b> Cytogenetic analysis of the bone marrow aspirate specimens of 91 patients was performed by standard Giemsa (G)-banding and interphase FISH (iFISH). <b><i>Results:</i></b> 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 <i>RUNX1</i> (<i>n</i> = 18, 21.4%), followed by <i>ETV6/RUNX1</i> fusion (<i>n</i> = 7, 8.3%), and gain of <i>KMT2A</i> (<i>n</i> = 6, 7.1%). Additionally, rarely reported gains of <i>ETV6</i>, <i>PBX1,</i> and <i>ABL1</i> were observed at a frequency of 6% (<i>n</i> = 5), and the deletion of <i>ETV6</i> and <i>TCF3</i> was seen at a frequency of 3.6% (<i>n</i> = 3) and 2.3% (<i>n</i> = 2), respectively. A 10-year old with intrachromosomal amplification of chromosome 21 was also observed. <b><i>Conclusions:</i></b> This study strengthens and widens the current knowledge of the cytogenetic landscape of pediatric ALL.