Acute Myeloid Leukemia with NUP98-RARG Gene Fusion Similar to Acute Promyelocytic Leukemia: Case Report and Literature Review

Retinoic acid receptor gamma (RARG) belongs to the nuclear receptor superfamily and has 90% homology to RAR alpha (RARA) and RAR beta. The promyelocytic leukemia (PML)–RARA fusion gene has been implicated in acute promyelocytic leukemia (APL). RARG gene rearrangement has been identified in a rare subtype of acute myeloid leukemia (AML) that resembles APL. To date, only 10 cases of gene rearrangements involving RARG (nucleoporin [NUP]98–RARG, promyelocytic leukemia protein–RARG, cleavage and polyadenylation-specific factor 6–RARG, or nucleophosmin [NPM]1–RARG–NPM1) have been reported. These patients show characteristics similar to APL, including bone marrow morphology, coagulation abnormality, and immunophenotype; however, they are resistant to all-trans retinoic acid and arsenic trioxide treatment. Moreover, there is no optimal therapeutic regimen for this subtype of AML. In this study, we report the clinical presentation and experimental findings of a case of AML with NUP98–RARG gene fusion similar to APL and review other cases of RARG gene rearrangement described in the literature.