Patients with classical acute promyelocytic leukemia (APL) are characterized by t(15; 17)(q22; q21), which results in the fusion of PML/RARA. Variant APL patients are rare clinically, and there are many related fusion genes, including ZBTB16/RARA, NPM/RARA, NuMA/RARA, STAT5b/RARA, PRKAR1A/RARA, FIP1L1/RARA, BCOR/RARA, OBFC2A/RARA, TBLR1/RARA, GTF2I/RARA, IRF2BP2/RARA, FNDC3B/RARA, STAT3/RARA, NUP98/RARG, PML/RARG, CPSF6/RARG, RARG/CPSF6, NPM1/RARG/NPM1, TBL1XR1/RARB fusion genes, etc.. Those variant fusion genes are involving retinoic acid receptor (RAR) A, RARB and RARG. Different variant APL related fusion genes possess respective molecular characteristics, leading to various efficacy and clinical outcomes of patients. This article summarizes the breakthroughs in the pathogenesis of variant APL, as well as the structure, function, pathogenic mechanism of variant APL related fusion genes and patients response to treatment.
