Mucopolysaccharidosis type VII (MPS VII) is a lysosomalproduced low GUS activity in several tissues. This latter storage disease caused by a genetic deficiency of ␤-glucutreatment of MPS VII mice reduced glycosaminoglycan ronidase (GUS). We used a recombinant adeno-associalevels in the liver to normal and reduced storage granules ted virus vector (AAV-GUS) to deliver GUS cDNA to MPS dramatically. We show that a single administration of VII mice. The route of vector administration had a dramatic AAV-GUS can provide sustained expression of GUS in a effect on the extent and distribution of GUS activity. Intravariety of cell types and is sufficient to reverse the disease muscular injection of AAV-GUS resulted in high, localized phenotype at least in the liver. production of GUS, while intravenous administration