KMT2A amplification: rare cytogenetic abnormality in a case of pediatric acute lymphoblastic leukemia
Dhara Shah, Velu Nair, Chaitrangi Rohekar, Vijaykumar Shirure, Sandipkumar Kheni, Neha Motwani, Grishma Sukhwal, Raj Gabani, Yoshaan Joshi<p><strong>Background:</strong> Rearrangements or translocations involving the <em>KMT2A</em> 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, <em>KMT2A</em> 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 <em>KMT2A</em> amplification in pediatric ALL remains unclear, although available reports in adult cases suggest an association with poor outcomes.</p> <p><strong>Case Presentation:</strong> This is a case of <em>KMT2A</em> 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 <em>KMT2A</em> 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.</p> <p><strong>Conclusion:</strong> 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.</p>