Individuals with familial myelodysplastic syndromes (MDS), which is associated with mutations in the RUNX1 gene, have a median AML incidence of 35% in carriers, but this varies greatly between families, as does the age of onset, which ranges from childhood to old age even within the same family (Owen et al., 2008). The gene discussed is RUNX1; the disease is acute myeloid leukemia.