This study involves the one-time collection of whole blood or saliva samples for the extraction and storage of DNA for use in ongoing and future ChiLDReN studies.

The purpose of this study is to establish a mechanism to collect a genetic biosample from the participants previously enrolled into clinical research under ChiLDReN-supported protocols (PROBE and BASIC). The samples will be linked to the data previously collected on the participant. Samples will be stored in the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) specimen repository and will be used in ongoing and future Network and Ancillary Studies of ChiLDReN to further address the pathophysiology and outcomes of these liver diseases.

Inclusion Criteria:

• For Child Participants

  1. Previous enrollment in PROBE or BASIC

  2. Exited from one of the aforementioned studies.

  3. Consent for DNA sample collection obtained during enrollment during enrollment to one of the aforementioned studies but sample not previously collected.

  4. Still followed at the clinical site.

     Exclusion Criteria:

  1. Participant is deceased
  2. Participant exited from prior study due to violating eligibility criteria
  3. Participant cannot be contacted

The eligible study population are those child participants who signed consent to participate in a prior research study that collects DNA biospecimens and for whom the specimen was never obtained. If those participants are still followed by the site.