Final answer:
Dubin-Johnson syndrome involves a genetic defect resulting in the liver's inability to excrete conjugated bilirubin properly, leading to its accumulation in the blood and chronic jaundice.
Step-by-step explanation:
Dubin-Johnson Syndrome and Bilirubin Excretion
Dubin-Johnson syndrome is characterized by a defective hepatic excretion of conjugated bilirubin, leading to an increase in its levels within the blood. This condition is a rare, autosomal recessive disorder that affects the liver's ability to process and excrete bilirubin properly. Unlike other forms of jaundice where both unconjugated and conjugated bilirubin are elevated, in Dubin-Johnson syndrome, the increase is primarily in conjugated bilirubin as the liver can still conjugate bilirubin but cannot effectively excrete it into the bile. The syndrome is not associated with liver damage but can lead to chronic jaundice. Diagnosis is typically confirmed through imaging studies and liver biopsy, indicating darkly pigmented liver cells due to the accumulation of bilirubin.