Patient ALMA_8_BM (39–60 years, male; coverage 7.77x), transitioning from MDS to AML (40% blasts, RUNX1T1 copy gain), was confidently classified as MDS-related secondary myeloid subtype, corroborated genomically by SF3B1, KRAS, and TP53 pathogenic mutations. This evidence concerns the gene RUNX1T1 and myelodysplastic syndrome.