Autosomal Recessive Polycystic Kidney Disease (ARPKD) is a rare condition affecting the kidneys and sometimes the liver. This study aims to collect medical data and samples from people with ARPKD and similar diseases, to help researchers understand and find better ways to treat these conditions. The study does not require visiting a clinic. Instead, medical information like clinic notes and lab results will be collected and stored in a special database. Participants can also choose to give blood, saliva, or tissue samples for research.

• Participation: No clinic visits needed; ongoing data collection for the study.
• Sample Collection: Blood or saliva samples may be required; collected and stored safely.
• Privacy: All personal identifiers will be removed from records to protect privacy.

This research will help doctors and scientists better understand ARPKD and related diseases, and the collected data and samples will be stored at the Children's Hospital of Philadelphia (CHOP). To join, participants need to show evidence of having the disease through tests or medical records.