The aims of the study were (i) to investigate the clonal heterogeneity of MDS and AML bone marrow samples based on TP53 gene mutation status, (ii) to find a correlation between mutation status and the severity of hematopoietic disorders, and (iii) to investigate the alterations of p53 protein upon mutations in silico. The gene discussed is TP53; the disease is myelodysplastic syndrome.