TP53 and myelodysplastic syndrome: However, cytogenetic abnormalities predicted to cause copy number loss at the TP53 locus had no prognostic impact regardless of TP53 mutations status (Supplemental Fig. 4), suggesting that loss of a TP53 allele by cytogenetic analysis might not be biologically equivalent to a TP53 point mutation in CK-MDS [2, 5, 35, 36].