Approaches to gene therapy in disorders of purine metabolism.

Model studies with gene transfer technology using retroviral vectors expressing the cloned human genes for adenosine deaminase (ADA), purine nucleoside phosphorylase (PNP), and hypoxanthine guanine phosphoribosyltransferase (HPRT) indicate that these disorders may eventually be treated by the introduction of the normal gene into defective cells. The autologous transplantation of bone marrow infected in vitro with retroviral vectors is the most developed approach at this time. The potential usefulness of this and other approaches for each of these three disorders of purine metabolism are discussed.