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 #Hyperbilirubinemia #Inherited #Congenital #bilirubin #hepatology #diagnosis #gastroenterology
