Combined Mutations of Canalicular Transporter Proteins Cause Severe Intrahepatic Cholestasis of Pregnancy  Verena Keitel, Christoph Vogt, Dieter Häussinger, Ralf Kubitz  Gastroenterology  Volume 131, Issue 2, Pages 624-629 (August 2006) DOI: 10.1053/j.gastro.2006.05.003 Copyright © 2006 American Gastroenterological Association Institute Terms and Conditions

Figure 1 Liver function tests in the course of the disease. Serum bile salt, transaminase, bilirubin, and γ-glutamyltransferase (γ-GT) levels were monitored during pregnancy. Values are expressed as x-fold of upper normal values, which were 8 μmol/L for bile salts, 31 U/L for aspartate aminotransferase, 35 U/L for alanine aminotransferase, 1.1 mg/dL (18.7 μmol/L) for bilirubin, and 38 U/L for γ-GT. Aspartate aminotransferase and alanine aminotransferase levels became normal, while bile salt levels gradually increased after therapy with ursodeoxycholate (UDCA) was initiated. Spontaneous delivery occurred in the 35th week (large arrows). Gastroenterology 2006 131, 624-629DOI: (10.1053/j.gastro.2006.05.003) Copyright © 2006 American Gastroenterological Association Institute Terms and Conditions

Figure 2 Topology models of MDR3 and BSEP. Amino acid sequences were derived from NP_000434.1 (MDR3) and NP_003733.1 (BSEP). Transmembrane domains were estimated according to Tusnády (http://www.enzim.hu/hmmtop/index.html). Topology models were drawn by the use of the transmembrane protein display software TOPO2 by S. J. Johns (http://www.sacs.ucsf.edu/TOPO/topo.html). The mutations found in this patient are within the fifth transmembrane domain (MDR3, S320F) and in the nucleotide binding fold (BSEP, V444A). The relevant sequences from the patient, her mother, and aunt are shown. Gastroenterology 2006 131, 624-629DOI: (10.1053/j.gastro.2006.05.003) Copyright © 2006 American Gastroenterological Association Institute Terms and Conditions

Figure 3 Immunofluorescence staining of BSEP in liver slices. In control livers, BSEP (A, K24; B, K168; red), MDR3 (green), and the multidrug resistance-related protein 2 (MRP2, green) were all strongly expressed and colocalized at the canalicular membrane. In the patient’s liver MDR3 immunofluorescence (green) was normal, while BSEP immunoreactivity (K24 and K168; red) was markedly reduced. Bars = 10 μm. Gastroenterology 2006 131, 624-629DOI: (10.1053/j.gastro.2006.05.003) Copyright © 2006 American Gastroenterological Association Institute Terms and Conditions