Specific diseases Alagille syndrome		Alagille syndrome (AGS) is an autosomal dominant disorder characterized by paucity of the intrahepatic bile ducts, peculiar facies and congenital cardiac, skeletal and ocular anomalies. Also referred to as arteriohepatic dysplasia or syndromic bile duct paucity, it is the most common familial cause of direct jaundice in the newborn. It typically presents in the first 2 years of life with chronic cholestasis. The diagnosis of AGS is based on: Liver biopsy findings of interlobular bile duct paucity AND at least 3 of 5 major clinical features chronic cholestasis cardiac disease skeletal abnormalities ocular abnormalities characteristic facies Renal, neurovascular and pancreatic anomalies are seen less frequently Hepatic disease presents in infancy with symptoms ranging from mild cholestatic jaundice and pruritis to progressive liver failure and failure to thrive. Lab findings include increased serum bile acids, direct bilirubin, alkaline phosphatase, cholesterol and GGTP. Growth failure occurs in over 50% of patients. Progression to liver failure occurs in a large percentage; about 15% will require liver transplantation. It is important to correctly diagnose AGS. If misdiagnosed as BA and treated with portoenterostomy, outcome is much worse with progressive cholestasis and liver failure. In 1977, the genetic abnormality of AGS was identified on the short arm of chromosome 20 (20p12). Return to top of page