Dubin-Johnson syndrome (SDJ) is a benign hereditary liver disease, which is characterized by chronic hyperbilirubinemia (conjugated bilirubin predominantly). From the histopathological point of view, deposits of blackish-brown pigments in hepatic parenchymal cells can be observed.
The prevalence in the general population is unknown. The SDJ affects individuals of all ethnicities, but is more common among Iranians and Moroccan Jews, with a maximum prevalence of 1/1,300 individuals.
Adolescent patients or young adults usually have mild or moderate recurrent jaundice, without pruritus, normally triggered by an intercurrent illness, pregnancy, oral contraceptives or medications. Fatigue and abdominal pain are sometimes observed during outbreaks and, in exceptional cases, hepatosplenomegaly may occur.
The total bilirubin level in serum (particularly in the conjugated form: the percentage of total and conjugated serum bilirubin is 50-80%) is high, usually between 2 and 5 mg/dl (very rarely above 20 mg/dl).
SDJ is inherited with an autosomal recessive pattern and it is caused by homozygous mutations in the ABCC2 gene. This gene codes for the ATP-dependent apical membrane transporter that mediates the flow of bilirubin-glucuronide and other conjugated organic anions of hepatocytes in the bile.
The definitive diagnosis can be obtained by molecular analysis of the ABCC2 gene. Although histological analysis can also provide a definitive diagnosis, liver biopsy is not performed systematically considering its invasive nature and the benign prognosis of the disease.
There is no treatment for SDJ, although it has been observed that short-term administration of phenobarbital reduces serum bilirubin levels in some cases. SDJ is a benign disorder and the prognosis is good. No evolution of the disease to liver failure, cirrhosis or liver fibrosis has been observed.
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