The primary goal of this research study is to learn if patients with autosomal recessive polycystic kidney disease (ARPKD) are at risk for brain aneurysms or cardiovascular abnormalities.Participants in this study will involve patients that have a clinical diagnosis of ARPKD.The study will also involve a comparison group of healthy individuals that have no history of kidney or cardiac conditions.

The primary goal of this research study is to see if new types of magnetic resonance imaging (MRI) can be used to measure liver health in children with autosomal recessive polycystic kidney disease (ARPKD) compared to healthy controls. Both children with ARPKD and healthy children, aged 6 years and above can participate.

The purpose of this study is to identify components of a physical activity intervention that are effective and meaningful to teenagers with chronic kidney disease (CKD).

Participants will be assigned to 1 of the 16 study groups and will be asked to wear a Fitbit. Participants will also be given a step count goal, answer questionnaires, and complete hand grip strength assessments.

Participants may also be asked to have one-on-one meetings with an exercise coach.

All visits may be completed remotely.