TP53 and acute myeloid leukemia: Mutations of TP53 are observed in primary MDS and AML de novo (5–10%) and, more commonly, in t-MN (25–30%).35,38 The spectrum of mutations includes missense mutations in exons 4–8, as well as loss of the wild type allele, typically as a result of a cytogenetic abnormality of 17p.