gene therapy, a procedure that involves injection of “healthy genes” into the bloodstream of a patient to cure or treat a hereditary disease or similar illness. Blood is withdrawn from the patient; the white cells are separated and cultured in a laboratory. Normal genes from a volunteer are inserted into modified viruses, which, in turn, transfer the normal gene into the chromosomes of the patient’s white cells. The white cells containing the normal genes are finally injected into the patient’s bloodstream. A clinical application of gene therapy may be found in the treatment of thalassemia, a genetically determined disease, in which efforts have been made to increase hemoglobin F production and improve the level of anemia. Research goals include changing the actual hemoglobin genes in red blood cell precursors or transplantation of normal hemoglobin genes into the bone marrow of thalassemia patients. Also called somatic-cell gene therapy.
