Authors: Dhara Shah , Chaitrangi Rohekar , Vijaykumar Shirure , Sandipkumar Kheni , Neha Motwani , Grishma Sukhwal , Raj Gabani , Yoshaan Joshi , Velu Nair ,

Abstract

Background: Rearrangements or translocations involving the KMT2A gene are well-recognized genetic abnormalities in acute lymphoblastic leukemia (ALL) across both adult and pediatric populations, and their presence is typically associated with adverse prognosis and high-risk disease. In contrast, KMT2A gene amplification is an exceedingly rare abnormality in ALL, with only a few reported cases till date, predominantly in adults. Owing to its extreme rarity, the prognostic significance of KMT2A amplification in pediatric ALL remains unclear, although available reports in adult cases suggest an association with poor outcomes.

Case Presentation: This is a case of KMT2A amplification in a 4-year-old child diagnosed with B-cell ALL who presented with standard-risk disease features and achieved complete remission following induction chemotherapy, maintaining remission at 12 months post-diagnosis. Similar findings from limited Western literature also suggest that KMT2A amplification does not adversely affect clinical outcomes in pediatric cases. To the best of our knowledge, this is the first reported case of this rare genetic abnormality in pediatric ALL from India.

Conclusion: This case highlights a rare cytogenetic abnormality—KMT2A amplification—in pediatric ALL, which, despite being an adverse prognostic factor in adult acute leukemia, did not appear to negatively impact clinical outcome in the pediatric age group.

Keywords: Pediatric ALL, KMT2A amplification, rare gene amplification, ALL cytogenetics, acute leukemia, case report.