22. Characterization of atypical iAMP21 observed in B-Lymphoblastic Leukemia (B-ALL): A retrospective study from Mayo Clinic

Accounting for ∼2% of B-ALL, iAMP21 is a recurrent genetic abnormality defined by the presence of ≥ 5 copies of the RUNX1 gene or ≥ 3 extra copies of RUNX1 on a single abnormal chromosome 21 by fluorescence in situ hybridization (FISH) using the ETV6/RUNX1 probe. Our goal was to evaluate the performance of the ETV6/RUNX1 probe in identifying iAMP21.