Clonal selection of 11q CN-LOH and CBL gene mutation in a serially studied patient during MDS progression to AML.

By conventional metaphase and SNP array cytogenetics we serially studied a patient affected by high-risk myelodysplastic syndrome (MDS), documenting the conversion from partial trisomy 8q to trisomy 8 and partial tetrasomy 8q during progression to acute myeloid leukemia (AML). Moreover, the serial application of high resolution genomic array analysis at different disease stages allowed the description of cryptic abnormalities and the demonstration of their enrichment in the AML phase. In particular the detection and quantification of a copy-neutral loss of heterozygosity region located in chromosome 11q guided the search for point mutations in the CBL gene, thus allowing the escription of the novel missense mutation K382E and the demonstration of its selection during progression to secondary AML.