Identification of novel NUP98::RARA fusion transcripts in acute promyelocytic leukemia with i(17)(q10) abnormality.

Acute promyelocytic leukemia (APL) is one subtype of acute myeloid leukemia (AML) primarily associated with the typical fusion gene PML::RARA/t(15;17). A small percentage of APL cases are caused by atypical gene transcript variants lacking the PML::RARA. We report one case with two novel NUP98::RARA fusion transcripts in APL lacking the fusion gene PML::RARA/t(15;17). These NUP98::RARA fusion transcripts were identified using next-generation sequencing (NGS), which were confirmed by Sanger sequencing. One of the transcripts differs from the previously reported transcript in terms of break sites and transcript length, which identified as subtype of NUP98::RARA fusion transcript. The other one is the same as previously reported, demonstrating reproducible abnormality of this fusion gene. The patient was treated with all-trans retinoic acid (ATRA), realgar-Indigo naturalis formula (RIF) and chemotherapy. According to the published paper, this is the second report of NUP98::RARA fusion transcript in APL. It is also the first variant APL with der(11)(p15)t(11;17)(p15;q21) and i(17)(q10) chromosome abnormalities. Therefore, we compared and summarized these two cases.