Inherited Non-hemolytic Disorders of Hyperbilirubinemia 



== Disorders of Conjugation ==

Gilbert Syndrome:

 • 5-10% of the population

 • Most common hereditary hyperbilirubinemia syndrome

 • An autosomal recessive syndrome

 • Has a UGT1A1 activity level of about 30% of normal

 • Patients typically present as mild, intermittent unconjugated hyperbilirubinemia in otherwise asymptomatic young adults without evidence of hemolysis or liver injury.

 • Associated with: breastfeeding jaundice and breastmilk jaundice

 • May manifest only as jaundice on clinical examination; nonspecific symptoms, such as abdominal cramps, fatigue, and malaise, are common

Crigler-Najjar Syndromes:

 • Type I CN is a super rare, autosomal recessive disorder in which patients have no UGT1A1 activity

 • Presents shortly after birth with serum bilirubin levels greater than 20 to 50 mg/dL. Newborn: associated with bilirubin encephalopathy

 • Type II CN is an autosomal dominant disorder in which patients have some UGT1A1 activity

 • Unconjugated hyperbilirubinemia occurs in the first days of life

 • Bilirubin levels ranging from 7-20 mg/dL

 • CN syndrome type II rarely results in kernicterus.

 • Older children and adults, illness and stress may cause temporary increases in bilirubin levels.



== Disorders of Reuptake ==

Rotor Syndrome:

 • Autosomal recessive disorder in which patients have an increase in conjugated bilirubin in the blood

 • Defect in hepatic uptake and storage.

 • Disorder is indistinguishable from DJS and presents with predominantly a mixed conjugated and unconjugated hyperbilirubinemia in otherwise asymptomatic individuals



== Disorders of Excretion into Bile ==

Dubin-Johnson:

 • Autosomal recessive disorder

 • Increase in conjugated bilirubin

 • Defect in secretion of bilirubin glucuronides across the canalicular membrane

 • Patients are missing a canalicular protein that transports bilirubin glucuronides into bile



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