A Study Observing the Long-term, Effectiveness and Safety of Odevixibat (Bylvay) in Patients With Alagille Syndrome (ALGS) Who Are Receiving Ongoing Treatment

Inclusion Criteria: * Diagnosed with ALGS. * On (or starting) active odevixibat treatment. * Signed informed consent and assent, as appropriate. Consent/assent from the participant or legal representative should be obtained, as appropriate, before any study data collection is conducted. Participants who turn 18 years of age (or legal age per country) while participating in the study will be required to provide consent for themselves. Exclusion Criteria: * Currently participating in a clinical trial with odevixibat. * Currently participating in any interventional clinical trial for ALGS. * Have any contraindication to odevixibat as per the locally approved label. * Had liver transplant before enrolment