Unconjugated hyperbilirubinemia in neonate is seen in all of the following except –
**Core Concept**
Unconjugated hyperbilirubinemia in neonates refers to an elevated level of unconjugated bilirubin in the blood, which is a common cause of jaundice in newborns. This condition occurs due to an imbalance between the production of bilirubin and its conjugation or clearance from the body.
**Why the Correct Answer is Right**
Unconjugated bilirubin is primarily produced from the breakdown of red blood cells. In neonates, unconjugated hyperbilirubinemia can occur due to increased bilirubin production, decreased uptake of bilirubin by the liver, or impaired conjugation of bilirubin by the enzyme glucuronyl transferase. Conditions such as hemolysis, biliary atresia, and Crigler-Najjar syndrome can lead to unconjugated hyperbilirubinemia.
**Why Each Wrong Option is Incorrect**
**Option A:** While hemolysis can cause unconjugated hyperbilirubinemia, it is not the only cause, and this option is too narrow. Hemolysis is a correct cause, but A is incorrect because there is another cause listed below.
**Option B:** Biliary atresia is a correct cause of unconjugated hyperbilirubinemia, as it leads to impaired conjugation of bilirubin.
**Option C:** Crigler-Najjar syndrome is a correct cause of unconjugated hyperbilirubinemia, as it results from a deficiency of the enzyme glucuronyl transferase.
**Clinical Pearl / High-Yield Fact**
It is essential to note that unconjugated hyperbilirubinemia can lead to kernicterus, a condition characterized by brain damage due to high levels of bilirubin. Kernicterus can occur if bilirubin levels exceed 20 mg/dL.
**Correct Answer:** D