Cholestasis is a condition in which bile is not properly transported from the liver to the small intestine. Cholestasis can be caused by an array of childhood diseases, including the genetic diseases Alagille syndrome (ALGS), alpha-1 antitrypsin (a-1AT) deficiency, bile acid synthesis and metabolism defects, and progressive familial intrahepatic cholestasis (PFIC) or benign recurrent intrahepatic cholestasis(BRIC). This study will investigate the natural history and progression of the four previously mentioned cholestatic liver diseases to provide a better understanding of the causes and effects of the diseases.

Cholestasis is a rare condition that involves a reduction or obstruction of bile flow from the liver to the small intestine. When bile flow is hindered, a waste product pigment called bilirubin can escape into the bloodstream and build up to harmful levels. This may lead to the easily recognizable cholestatic symptoms of jaundice, itching, and impaired growth and eventually to more serious health problems. Four rare genetic liver disorders- ALGS, a-1AT, bile acid synthesis and metabolism defects, and PFIC-account for about 20% to 30% of all infant cases of cholestasis. These four disorders compose a group of related diseases that can cause significant growth problems during childhood, serious liver problems, the need for liver transplantation, and potentially death. More research on these rare liver diseases is necessary to develop a scientific basis for improvement in diagnostic techniques and treatments. Current diagnostic procedures are complex, and the development of simpler diagnostic tests would facilitate early diagnosis and treatment. This study will investigate the natural history and progression of the four previously mentioned cholestatic liver diseases to provide a better understanding of the causes and effects of the diseases.

Participants who have been previously enrolled into this study will be followed for 20 years, until transplanted, or death. Study visits will involve review of clinical information, family history, and any clinically indicated treatments and their outcomes; a physical exam; laboratory tests; and radiologic and imaging evaluations.

Inclusion Criteria:

1. Children and young adults diagnosed with one of the four cholestatic diseases from birth through 25 years old.
2. Siblings of participants with alpha-1-antitrypsin deficiency, who are affected with alpha-1-antitrypsin deficiency, but have no evidence of liver disease.
3. Both sexes, all races and ethnic groups.
4. Participant meets the enrollment criteria for one of the four cholestatic liver diseases.
5. Patient and/or parent/legal guardian have the ability to provide written informed consent for enrollment.

Exclusion Criteria:

1. Inability to comply with the longitudinal follow-up described in the protocol.

The study population will consist of 400 participants with Alagille syndrome, 400 with alpha-1 trypsin deficieny (of which up to 25 may be siblings of participants), 300 with PFIC (or BRIC), and 50 with bile acid synthesis defects.

The data will be transferred to NIDDK at the end of the study.