PFIC - Progressive Familial Intrahepatic Cholestasis

Progressive Familial Intrahepatic Cholestasis (PFIC) is a group of inherited conditions that affect how bile moves in the liver, which can lead to serious liver problems. Doctors usually recommend genetic testing for patients with unexplained bile issues-after ruling out more common causes-to better understand the problem. However, there isn't much information on how common these genetic changes are in adults with these liver issues, especially in Spain. This study will observe these genetic changes so that doctors can diagnose the condition more clearly and create personalized treatment plans. This study will be conducted in several centers across Spain for 10 months. Each adult participant will take part in a single-day visit where their health information will be collected, and a blood sample will be taken for both routine tests and genetic analysis.

The purpose of this study is to create a national, multi-centre registry for children with Alagille syndrome (ALGS) and Genetic Intrahepatic Cholestasis (GIC) that follows participants long-term, ensuring standardized, high-quality data capture across all participating pediatric hepatology centres. Inclusion criteria: • Pediatric participants (\<18 years old) with genetically confirmed or clinically diagnosed ALGS or any of the various subtypes of GIC, each associated with a distinct genetic mutation: A. PFIC Type 1 (FIC1 Deficiency) - Mutation in ATP8B1 gene. B. PFIC Type 2 (BSEP Deficiency) - Mutation in ABCB11 gene. C. PFIC Type 3 (MDR3 Deficiency) - Mutation in ABCB4 gene. D. PFIC Type 4 (TJP2 Deficiency) - Mutation in TJP2 gene. E. PFIC Type 5 (FXR Deficiency) - Mutation in NR1H4 gene. F. PFIC Type 6 (MYO5B-Associated) - Mutation in MYO5B gene. G. Progressive cholestasis of northwestern Quebec (PCNQ)-Mutation in UTP4 gene. * Enrollment within Canadian pediatric liver centers participating in the registry. * Written informed consent obtained from participant if they have the capacity, or parents/guardians, and assent from participants as appropriate. Exclusion criteria: • Inability to comply with follow-up requirements (lost to follow-up). Participants will be recruited from our hepatology clinics retrospectively (diagnosed on or after January 1, 2022) and prospectively (newly diagnosed). Written consent/assent will be obtained from all participants prior to data collection from the participants' medical chart.