An infant normal at birth now appears jaundiced at 6 weeks. This is a typical presentation of which disorder?

The presentation of jaundice in an infant who was normal at birth, particularly when it appears around 6 weeks of age, is indicative of biliary atresia. This condition is characterized by the obstruction of bile ducts, which leads to a buildup of bile in the liver and subsequently causes jaundice.

In biliary atresia, the infant typically appears healthy at birth, but the obstruction becomes apparent as they grow. The progression of jaundice in these infants can be associated with pale stools, dark urine, and abdominal distension as the liver function deteriorates. Early detection is crucial, as treatment often involves surgical intervention to restore bile flow or liver transplantation if the condition is severe.

Other conditions, such as hepatitis or neonatal hemolytic disease, typically present with jaundice at different stages and have different causes and presentations. For example, hepatitis might not present specifically at 6 weeks or would be accompanied by other systemic signs of illness. Neonatal hemolytic disease usually manifests within the first few days of life due to Rh or ABO incompatibility, causing rapid jaundice due to increased breakdown of red blood cells. Glucose-6-phosphate dehydrogenase deficiency tends to cause jaundice due to hemolysis but often presents