Inclusion Criteria:  Diagnosis of OTC deficiency, GSDIa, or Wilson Disease. Provide informed consent after the nature of the study has been explained, and prior to any research-related procedures.  Exclusion Criteria:  Prior exposure to an AAV-based gene therapy. Concurrent or previous participation in another Ultragenyx clinical study. Recipient of a liver transplant. Presence or history of any condition that, in the view of the Investigator, would interfere with participation, pose undue risk, or would confound interpretation of results.