Key genomic events in non–DS-AMKL. A total of 142 pediatric non–DS-AMKL cases were analyzed for the presence of fusion gene events by transcriptome sequencing, reverse-transcription polymerase chain reaction (RT-PCR), or split-signal fluorescence in situ hybridization. A total of 96 samples were evaluated for the presence of the MLL-PTD by RT-PCR and 46 samples were evaluated for the presence of somatic GATA1 single-nucleotide variations and insertion/deletion by exome and/or Sanger sequencing. The proportion of MLL-PTD and GATA1 mutant cases was calculated based on the total number of samples evaluated for each of the lesions. Patients carrying GATA1 mutations did not have stigmata of DS or evidence of mutant reads in germline DNA, suggesting they are not mosaics. Cases that did not undergo transcriptome sequencing and were negative by RT-PCR for CBFA2T3-GLIS2, NUP98-KDM5A, RBM15-MKL1, and MLL rearrangements (MLLr) are designated as unknown. “Other fusion” includes single cases of each of the following: GATA2-HOXA9, NIPBL-HOXB9, MN1-FLI1, HLXB9-ETV6, FUS-ERG, and RUNX1-CBFA2T3. Data compiled from Gruber et al¹⁶  and de Rooij et al.¹⁷