Reviewed by Rishi Desai, MD, MPH
Jaundice, also known as icterus, is a yellowish pigmentation of the skin, the conjunctival membranes over the sclerae (whites of the eyes), and other mucous membranes caused by high blood bilirubin levels. This hyperbilirubinemia subsequently causes increased levels of bilirubin in the extracellular fluid. Concentration of bilirubin in blood plasma is normally below 1.2 mg/dL (<25µmol/L). A concentration higher than approx. 3 mg/dL (>50µmol/L) leads to jaundice. The term jaundice comes from the French word jaune, meaning yellow.
Gilbert's syndrome is a common genetic liver disorder that produces elevated levels of unconjugated bilirubin in the bloodstream due to the reduced activity of the enzyme Uridine 5'-diphospho-glucuronosyltransferase. This normally has no serious consequences, although mild jaundice may appear under conditions of exertion or stress.
Crigler–Najjar syndrome is a rare inherited disorder affecting the metabolism of bilirubin. It is caused by an absent UDP-glucuronosyltransferase enzyme. The disorder results in a form of nonhemolytic jaundice, which results in high levels of unconjugated bilirubin and often leads to brain damage in infants. The disorder is autosomal recessive.
Rotor syndrome is a rare, relatively benign autosomal recessive bilirubin disorder. It is a milder form of Dubin–Johnson syndrome, where both diseases cause an increase in conjugated bilirubin.
Dubin–Johnson syndrome is a rare, autosomal recessive, benign disorder that causes an isolated increase of conjugated bilirubin in the serum. Classically, the condition causes a black liver due to the deposition of a pigment similar to melanin. This condition is associated with a defect in the ability of hepatocytes to secrete conjugated bilirubin into the bile, and is similar to Rotor syndrome. It is usually asymptomatic, but may be diagnosed in early infancy based on laboratory tests. No treatment is usually needed.