Scientists have uncovered a critical genetic mutation in some patients with myelodysplastic syndromes -- a group of blood cancers that can progress to a fatal form of leukemia. The research team at Washington University School of Medicine in St. Louis also found evidence that patients with the mutation are more likely to develop acute leukemia. While this finding needs to be confirmed in additional patients, the study raises the prospect that a genetic test could one day more accurately diagnose the disorder and predict the course of the disease.