This study investigates Mucopolysaccharidosis I (MPS I), a rare genetic disorder. The purpose is to gather data on the natural history and progression of MPS I, as well as the clinical responses of patients receiving treatments such as enzyme replacement therapy. An enzyme replacement therapy is a medical treatment that replaces a missing or deficient enzyme in patients with certain genetic disorders.

Participants will be observed and data will be collected on their health outcomes. This is an observational study, meaning no treatment changes will be made by the study team. An observational study is a type of research study where data is collected by observing participants receiving routine care, without changing their treatment, which may focus on people using specific medications or having certain conditions to better understand how treatments work.

• Who can participate: Patients of any age with a confirmed diagnosis of MPS I can participate. A confirmed diagnosis includes documented deficiency in alpha-L-iduronidase enzyme activity, genetic mutations, or clinical signs of MPS I. Participants must complete a patient authorization form.
• Study details: Participants will continue their usual care while data is collected about their health outcomes. This study does not involve any changes to treatment or additional procedures.