Which autosomal disorder is characterized by a paucity of bile ducts and cardiac defects?

Alagille syndrome is indeed characterized by a paucity of bile ducts, known as bile duct paucity, and is also associated with cardiac defects, particularly concerning the outflow tract of the heart. This genetic disorder results from mutations in the JAG1 gene or, less commonly, the NOTCH2 gene, which play crucial roles in the development of various organs, including the liver and heart.

In Alagille syndrome, the limited number of bile ducts leads to cholestasis and liver dysfunction, while congenital cardiac abnormalities can include conditions such as ventricular septal defects or pulmonary stenosis. These key features help distinguish Alagille syndrome from other conditions that may affect the liver or heart but do not share this specific combination of bile duct and cardiac issues.

Other conditions like cystic fibrosis primarily affect the lungs and pancreas, while Wilson's disease involves copper metabolism and typically presents with liver disease, neurological symptoms, and psychiatric findings, but not a direct association with cardiac defects. Primary sclerosing cholangitis, on the other hand, is primarily a liver disease marked by bile duct inflammation and is frequently associated with inflammatory bowel disease but does not characteristically present with cardiac defects.