Harnessing the strength of a natural process that repairs damage to the human genome, a researcher from UT Southwestern Medical Center has helped establish a method of gene therapy that can accurately and permanently correct mutations in disease-causing genes. The findings are available online in Nature. By artificially initiating a DNA repair process known as homologous recombination, Dr. Matthew Porteus of UT Southwestern, working with scientists from Richmond, Calif.-based Sangamo Biosciences, was able to replace a mutated version of the gene that encodes a portion of the interleukin-2 receptor (IL-2R) in human cells, restoring both gene function and the production of the IL-2R protein. Mutations in the IL-2R gene are associated with a rare immune disease called severe combined immunodeficiency disease, or SCID. Children with SCID are unable to successfully fight off infections, and must constantly live in a germ-free environment. Their lifespans are usually shortened by systemic infection, and while bone marrow transplants can be used to treat the disease, they are not always successful.