Which one of the following condition is associated with unconjugated hyper bilirubinemia
## **Core Concept**
Unconjugated hyperbilirubinemia occurs when there is an increase in the bilirubin that has not yet been processed by the liver to make it water-soluble. This form of bilirubin is not soluble in water and is bound to albumin for transport to the liver. Conditions leading to unconjugated hyperbilirubinemia typically involve increased bilirubin production, decreased uptake of bilirubin by the liver, or decreased conjugation of bilirubin within the liver.
## **Why the Correct Answer is Right**
The correct answer, **Gilbert syndrome**, is associated with unconjugated hyperbilirubinemia due to a partial deficiency of the enzyme **UDP-glucuronyltransferase**, which is necessary for the conjugation of bilirubin. This deficiency leads to a decrease in the liver's ability to conjugate bilirubin, resulting in elevated levels of unconjugated bilirubin in the blood. Gilbert syndrome is a benign condition characterized by mild jaundice, particularly during periods of stress or fasting.
## **Why Each Wrong Option is Incorrect**
- **Option A: Dubin-Johnson syndrome** is incorrect because it is associated with **conjugated hyperbilirubinemia**. This condition results from a defect in the excretion of conjugated bilirubin into the bile due to a mutation in the ABCC2 gene, leading to an accumulation of conjugated bilirubin.
- **Option B: Rotor syndrome** is incorrect because it is also associated with **conjugated hyperbilirubinemia**, similar to Dubin-Johnson syndrome. It is characterized by chronic elevation of conjugated bilirubin without liver injury and is considered a benign condition.
- **Option C: Crigler-Najjar syndrome** is incorrect in the context of being listed as an option because, while it does involve unconjugated hyperbilirubinemia, **Dubin-Johnson and Rotor syndrome** are more distinctly associated with conjugated hyperbilirubinemia. However, Crigler-Najjar syndrome type I and II are related to severe and partial deficiency of UDP-glucuronyltransferase respectively.
## **Clinical Pearl / High-Yield Fact**
A key point to remember is that **Gilbert syndrome** is a common, benign condition that causes a mild increase in unconjugated bilirubin levels, often discovered incidentally during routine blood tests. It does not require treatment and is associated with a good prognosis. A classic clinical scenario for Gilbert syndrome is a patient with intermittent jaundice that worsens with fasting or illness.
## **Correct Answer: .**