Zellweger Spectrum Disorder

The goal of this observational study is to define the course of the retinal degeneration in a ZSD patient cohort. The objective of this study is to gather information so the investigators can: 1. define the course of the retinal degeneration in a ZSD patient cohort with retinal degeneration 2. define what tests best monitor the progression of the retinal degeneration 3. generate prognostic information about vision loss in ZSD. At each yearly visit, the participants will answer a functional vision questionnaire, have a physical evaluation, blood test, and participate in a variety of vision tests. The investigators will also collect pertinent medical history. Participants will travel to study site. The study will provide financial support for board and travel.

The Peroxisome Biogenesis Disorders (PBD) are a group of inherited disorders due to defects in peroxisome assembly causing complex developmental and metabolic sequelae. In spite of advancements in peroxisome biology, the pathophysiology remains unknown, the spectrum of phenotypes poorly characterized and the natural history not yet systematically reported. Our aims are to further define this population clinically, biochemically and genetically. The investigators will prospectively follow patients from Canada, the US and internationally, and collect data from medical evaluations, blood, urine and imaging studies that would be performed on a clinical care basis. For patients who are unable to attend our clinic, we will collect all medical records and images since birth as well as subsequent records/images for the next 5 years or until the end of the study. Clinical data from medical records will be banked in our Peroxisomal Disorder Research Databank and Biobank. The investigators will use this information to identify standards of care and improve management.