We are developing a new method to treat sickle cell disease, by directly correcting the abnormal beta-globin gene in patients’s own blood forming stem cells. This is being done using newly developed techniques to manipulate the genes within a cell and introduce a corrective change. In the studies to date over the first two years, we have demonstrated for the first time that these methods will correct the sickle cell-causing mutation in a subset of the stem cells and can lead to production of normal hemoglobin. However, this is still relative inefficient and less effective in the most useful stem cells that could grow in a patient for the rest of their life. Current efforts are underway to improve the gene correction methods so that more stem cells are corrected and can be used to transplant patients to eliminate their sickle cell disease. This approach will also be useful for treating other inherited diseases, especially those affecting blood cells.