An atypical RUNX1::ETV6::RUNX1 fusion in a pediatric patient with precursor B-cell acute lymphoblastic leukemia.
Aravindh Nagarajan, John Herriges, Lisa A Lansdon et al.
✦ AI-curated · Sources linked
Case in brief
A 2-year-old male presented with precursor B-cell acute lymphoblastic leukemia (B-ALL) and was found to have an atypical RUNX1::ETV6::RUNX1 fusion. Genetic analysis revealed an unusual signal pattern with multiple chromosome 21s involved. Comprehensive genomic profiling confirmed the fusion and its breakpoints. The patient was treated with a standard risk ALL protocol and has remained in remission for two years.
What made this case unusual
The atypical fusion involved excision and insertion of ETV6 exons into RUNX1, resulting in a novel fusion not typically seen in B-ALL cases.
Diagnostic / clinical pearl
Comprehensive genomic profiling, including optical genome mapping and long-read sequencing, can clarify atypical genetic findings in leukemia and aid in accurate sub-classification.
Why it matters
Understanding atypical fusions may inform risk assessment and treatment strategies in pediatric B-ALL, particularly in cases of relapse or drug resistance.