Myelodysplastic syndrome (MDS) is one of the most common blood cancers of the elderly. A bone marrow biopsy is usually required to make a diagnosis of MDS, but in many cases the diagnosis remains equivocal. In addition, the inconvenience and discomfort of a marrow biopsy causes many elderly patients with unexplained blood results to not receive this test. A non-invasive diagnostic test for MDS would be very useful to improve patient care and inform treatment options. It would also be beneficial to incorporate into the test a predictor of patient outcome. We have identified 269 regions of DNA that are significantly differentially methylated in blood neutrophils from MDS patients compared to normal elderly controls. In this project, these candidate markers for MDS will be confirmed in an independent cohort of MDS patients and developed into a commercial blood-based tool to be used in diagnostic laboratories.