Clonal evolution in myelodysplastic syndromes with isolated del(5q): the importance of genetic monitoring.

Myelodysplastic syndromes (MDS) with isolated deletion of chromosome arm 5q (del(5q)) have a good prognosis with low risk of transformation to acute myeloid leukemia (AML). Laboratory investigations typically demonstrate macrocytic anemia with preserved or increased platelet counts, and characteristic hypolobated megakaryocytes in the marrow (Figure 1A). Recent studies have provided significant insight into the pathogenesis of del(5q) MDS, and have demonstrated that additional mutations may alter the natural history of the disease.