Alagille Syndrome (ALGS) is a rare genetic disorder that affects multiple areas of the body such as the liver, face, eyes, heart, kidney, blood vessels, and bones. One of the most common organs that is affected is the liver. People with ALGS have a decreased number of bile ducts, which in a healthy liver allows bile to flow outside the liver to the gallbladder and ultimately to the small intestine to help with digestion of fats and absorb fat-soluble vitamins such as vitamin A, D, E, and K.
Because there is a decreased number of bile ducts in those with ALGS, there is a build-up of bile acids in the liver which leads to progressive liver damage, cholestasis (lack of or decreased bile flow), chronic liver disease (cirrhosis), and liver failure. ALGS often presents early in life or during early childhood and results in significant damage to the liver, issues with absorption of fat-soluble vitamins, and severe itching (pruritus). Patients, even those in the same family, can have differences in the number and severity of their symptoms. Many patients will eventually need surgery or a liver transplant.