Semin Liver Dis 2007; 27(1): 077-098
DOI: 10.1055/s-2006-960172
Copyright © 2007 by Thieme Medical Publishers, Inc., 333 Seventh Avenue, New York, NY 10001, USA.

MDR3 (ABCB4) Defects: A Paradigm for the Genetics of Adult Cholestatic Syndromes

Michael Trauner1 , Peter Fickert1 , Martin Wagner1
  • 1Laboratory of Experimental and Molecular Hepatology, Division of Gastroenterology and Hepatology, Department of Internal Medicine, Medical University of Graz, Austria
Further Information

Publication History

Publication Date:
12 February 2007 (online)


Because ATP-binding cassette (ABC) transporters are important for normal bile secretion, hereditary and acquired ABC transporter defects play a central role in the pathogenesis of cholestasis. Defects of the phospholipid export pump MDR3 (ABCC4) result in impaired biliary excretion of phosphatidylcholine and a variety of cholestatic syndromes ranging from progressive familial intrahepatic cholestasis in neonates to biliary cirrhosis in adults. Moreover, MDR3 mutations predispose to cholestasis of pregnancy and drug-induced cholestasis. Because Mdr2 (rodent orthologue of human MDR3) knockout mice develop sclerosing cholangitis, it is attractive to speculate that MDR3 defects could also play an important role in cholangiopathies in humans. Indeed, MDR3 variants could play a role as modifier gene in primary biliary cirrhosis and primary sclerosing cholangitis, but their exact role needs further clarification. Impaired biliary phosphatidylcholine excretion has also been reported in total parenteral nutrition-induced cholestasis and bile duct injury following liver transplantation, but a genetic basis for these findings remains to be explored. Several drugs for the treatment of cholestatic liver diseases target MDR3 expression and function, further underscoring the clinical significance of this transport system.


Michael Trauner, M.D. 

Professor of Medicine and Molecular Hepatology, Laboratory for Experimental and Molecular Hepatology, Division of Gastroenterology and Hepatology, Department of Medicine

Medical University of Graz, Auenbruggerplatz 15, A-8036 Graz, Austria