The route of administration was either intraparenchymal, using AAVrh10 or AAV5 vectors (MLD, MPSIIIA, MPSIIIB, and Batten disease), intracisternal using AAV9 or AAVrh10 vectors (MPSI, MPSII, and GM1 gangliosidosis), or intravenous using AAV9 (MPSIIIA, MPSIIIB, and GM1 gangliosidosis). This evidence concerns the gene IDUA and GM1 gangliosidosis.