Which condition results from deficient secretion of bilirubin into the bile canaliculi?

Dubin-Johnson syndrome is a disorder characterized by an impaired secretion of conjugated bilirubin into the bile due to a defect in the canalicular transport mechanism. In this condition, although the liver is able to produce and conjugate bilirubin effectively, the bilirubin cannot be properly excreted into bile, leading to an accumulation of conjugated bilirubin in the bloodstream. This accumulation results in mild to moderate jaundice, particularly noticeable in young adults.

Understanding the connection between bilirubin metabolism and Canalicular transport is key to recognizing why Dubin-Johnson syndrome specifically results from deficient secretion into the bile canaliculi. The condition does not typically cause significant hepatocellular injury or other liver function abnormalities; the major clinical manifestation is the elevated levels of bilirubin in the serum, reflecting the underlying transport defect.

Other conditions mentioned may involve increased bilirubin levels, but they do so through different mechanisms. For instance, Gilbert's disease primarily involves a reduced conjugation of bilirubin due to enzyme deficiency, while Crigler-Najjar syndrome relates to a more severe deficiency of the enzyme responsible for conjugating bilirubin, leading to hyperbilirubinemia. Neonatal hyperbilirubinemia typically arises from various factors, including imm