CC2 Disorders of Bilirubin Metabolism

Gilbert’s disease

benign autosomal recessive

hereditary disorder

underlying liver disease due to a

defective conjugation system in the

absence of hemolysis

genetic mutation in the UGT1A1 gene

⟶ uridine diphosphate

glucuronosyltransferase

bilirubin transport deficit

characterized by intermittent

unconjugated hyperbilirubinemia

UGTA1 gene

Gilbert’s disease has a mutation in which gene

Dubin-Johnson Syndrome

deficiency of canalicular multidrug resistance/

multispecific organic anionic transporter

protein(MDR2/cMOAT)

characterized by decreased hepatic excretion of

bilirubin

increased B2 with hepatic pigmentation

appearance of dark-stained granules on a liver

biopsy sample

total bilirubin concentration remains between 2

and 5 mg/dL, with more than 50% due to the

conjugated fraction

canalicular multidrug resistance/ multispecific organic anionic transporter protein(MDR2/cMOAT)

Dubin-Johnson Syndrome has a deficiency in?

Rotor syndrome

relatively benign condition

a reduction in the concentration or

activity of intracellular binding

proteins such as ligandin

a liver biopsy does not show dark

pigmented granules

Lucey Driscoll Syndrome

familial form of unconjugated

hyperbilirubinemia

caused by a circulating inhibitor of

bilirubin conjugatio

Crigler-Najjar Syndrome

syndrome of chronic nonhemolytic unconjugated

hyperbilirubinemia

an inherited disorder of bilirubin metabolism

resulting from a molecular defect within the gene

involved with bilirubin conjugation

characterized as primarily unconjugated

hyperbilirubinemias

conjugation deficit

Types:

Type 1 - complete absence of enzymatic bilirubin

conjugation

Type II - mutation causing a severe deficiency of

the enzyme responsible for bilirubin conjugation

Physiologic Jaundice of Newborn

deficiency in the enzyme UDPGT

Kernicterus

condition where very high bilirubin levels in the blood are deposited in the brain tissue causing irreversible damage to the brain