Torque Teno Mini Virus as a cause of childhood acute promyelocytic leukemia lacking PML/RARA fusion

We describe a case of a child affected by a relapsed PML/RARA-negative acute promyelocytic leukemia (APL) rescued by a combination of all-trans retinoic acid (ATRA) and arsenic trioxide (ATO) and subsequent HSCT. We provide evidence of the presence of a chimeric viral transcript generated through genomic integration of a Torque Teno Mini Virus sequence into RARA intron 2, the recurrent breakpoint of all chimeric RARA fusions found in APL. This generates an in-frame TTMV/RARA chimeric fusion that is highly expressed at disease diagnosis and relapse and fully cleared at remission achievement. Overall design: Whole transcriptome sequencing of acute promyelocytic leukemia lacking PML/RARA fusion