Sponsor decision not related to safety concerns

The objective of this observational study is to evaluate the seroprevalence of anti-AAV antibodies in subjects with Ornithine Transcarbamylase (OTC) deficiency, Glycogen Storage Disease Type Ia (GSDIa), and Wilson Disease

The study is primarily designed to follow a virtual model, in which Screening will take place over a telephone/video call. The study will comprise a single home health visit, either on the same day as Screening or within 30 days of enrollment. A safety follow-up may occur up to 5 days after Day 1 assessments are completed.

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.

Study population will include approximately equal proportions of subjects with OTC deficiency, GSDIa, and Wilson Disease