A Cryptic NUP214-ABL1Fusion in B-cell Precursor Acute Lymphoblastic Leukemia

Supplemental Digital Content is available in the text.Fluorescent in situ hybridization (FISH) analysis is the standard methods for screening ABL1fusions, which is recurrently translocated in pediatric acute lymphoblastic leukemia (ALL), and potentially targetable by kinase inhibitors. Here we demonstrated a case of B-cell precursor ALL with NUP214-ABL1fusion, which break-apart FISH assay for ABL1failed to detect. The cryptic fusion was generated by small duplication from ABL1to NUP214, which was detected by copy number analysis using genomic microarray and confirmed by PCR. In the context of precision medicine, we should establish how to screen targetable abnormalities for minimizing risk of false-negative.