Karyotype evolution of myelodysplastic syndrome and acute myeloid leukemia with TP53 mutations

To clarify karyotype evolution of myelodysplastic syndrome or acute myeloid leukemia with TP53 mutations (MDS/AML-TP53), we analyzed G-banding of bone marrow aspiration samples of eight patients with MDS/AML-TP53 and visualized the evolutions as phylogenetic trees. With very few exceptions, the initial roots of these trees and all branches longitudinally had -5/5q- and -7/7q- in common. Time series data of the karyotypes obtained in six patients showed highly complex karyotype evolutions, such as combined branched, linear, parallel, and macro-evolutions. In two patients, numerous branches appeared as the initial transformation. As for aneuploidy, chromosome loss was more common than chromosome gain as previously reported. Structural and numerical chromosomal abnormalities were often deleted as karyotype evolution progressed. Among these karyotype evolutions, loss of translocated chromosomes with break sites at or near the centromeres frequently caused monosomies of two chromosomes involved in the translocation. G-banding enables analysis and visualization of karyotype evolutions as phylogenetic trees because it offers the properties of both single-cell and whole-chromosome analysis. Our research has led us to propose G-banding as a new interpretation method for classical karyotype analysis.