ABCMdb

ABCB4 p.Thr175Ala

ClinVar:	c.523A>G , p.Thr175Ala D , Pathogenic
Predicted by SNAP2:	A: D (85%), C: D (85%), D: D (91%), E: D (91%), F: D (95%), G: D (85%), H: D (80%), I: D (95%), K: D (91%), L: D (91%), M: D (85%), N: D (59%), P: D (91%), Q: D (85%), R: D (95%), S: D (53%), V: D (95%), W: D (91%), Y: D (85%),
Predicted by PROVEAN:	A: D, C: D, D: D, E: D, F: D, G: D, H: D, I: D, K: D, L: D, M: D, N: D, P: D, Q: D, R: D, S: D, V: D, W: D, Y: D,

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[hide] Molecular characterization and structural implicat... Eur J Hum Genet. 2007 Dec;15(12):1230-8. Epub 2007 Aug 29. Degiorgio D, Colombo C, Seia M, Porcaro L, Costantino L, Zazzeron L, Bordo D, Coviello DA
Molecular characterization and structural implications of 25 new ABCB4 mutations in progressive familial intrahepatic cholestasis type 3 (PFIC3).
Eur J Hum Genet. 2007 Dec;15(12):1230-8. Epub 2007 Aug 29., [PMID:17726488]

Abstract [show]
Progressive familial intrahepatic cholestasis type 3 (PFIC3) is an autosomal-recessive disorder due to mutations in the ATP-binding cassette, subfamily B, member 4 gene (ABCB4). ABCB4 is the liver-specific membrane transporter of phosphatidylcholine, a major and exclusive component of mammalian bile. The disease is characterized by early onset of cholestasis with high serum gamma-glutamyltranspeptidase activity, which progresses into cirrhosis and liver failure before adulthood. Presently, about 20 distinct ABCB4 mutations associated to PFIC3 have been described. We report the molecular characterization of 68 PFIC3 index cases enrolled in a multicenter study, which represents the largest cohort of PFIC3 patients screened for ABCB4 mutations to date. We observed 31 mutated ABCB4 alleles in 18 index cases with 29 distinct mutations, 25 of which are novel. Despite the lack of structural information on the ABCB4 protein, the elucidation of the three-dimensional structure of bacterial homolog allows the three-dimensional model of ABCB4 to be built by homology modeling and the position of the mutated amino-acids in the protein tertiary structure to be located. In a significant fraction of the cases reported in this study, the mutation should result in substantial impairment of ABCB4 floppase activity. The results of this study provide evidence of the broad allelic heterogeneity of the disease, with causative mutations spread along 14 of the 27 coding exons, but with higher prevalence on exon 17 that, as recently shown for the closely related paralogous ABCB1 gene, could contain an evolutionary marker for mammalian ABCB4 genes in the seventh transmembrane segment.

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18 The two TMDs contain specific sites for substrate binding and translocation, whereas the two NBDs, which display a high degree of sequence similarity with the equivalent domain of ABC transporters, couple the energy obtained from ATP hydrolysis to substrate transport.8 The ICDs are deemed to be involved in mediating the coupling between NBD conformational changes and the reorientation of TM helices concomitant with substrate extrusion.9 The ABCB1 gene, one of the most extensively studied ABC transporters, is responsible for the human multidrug resistance phenotype that is a rapidly growing obstacle to the treatment of numerous infectious diseases, including human immunodeficiency10 and malaria.11 The properties of this transporter are also exploited in cancer pharmacological therapy where ABCB1 translocates the chemotherapeutic drugs and other molecules with a broad but defined specificity.12 A gene duplication of ABCB1 and additional mutations selected as advantageous have created in mammals the T715I G723E L724AfsX744 A737V G954S G762X T775M G126E S320F A840D OUT IN Linker region F357L L701P A364V NBD-NH2 terminal NBD-COOH terminal A1193T NH2 COOH 1 2 54 6 7 8 129 11 10 EC2EC1 ICD2 A250P Y279X A286V ICD1 R159X T175A ICD3 EC3 EC4 EC6EC5 ICD4 ICD6 ICD5 E888X Y403H V475A A511T E558K R590Q T593A M630V 3 S379KfsX413 P726T Figure 1 (a) Localization of the 29 mutations identified in this study in the ABCB4 protein, schematically represented in its domains. Login to comment
77 Notably, two mutations already described were found in members of different families that are not part of a genetic isolate: p.T175A and p.S320F were identified in unrelated Caucasian patients (three and two cases, respectively). Login to comment
84 There are no PFIC3 epidemiologic data available to date; however, knowing that the number of newborns in Italy has been on average 500 000/year in the last 14 years (http://demo.istat.it/), since we observed 18 patients with ABCB4-mutated alleles born within a 14-year period (with Table 2 Mutations identified in ABCB4 Type of mutationb Exons cDNA locusa Missense Frameshift or nonsense ABCB4-predicted domain GenBank accession numberc Exon 6 c.377G4A G126E TM2 DQ861346 Exon 6 c.523A4G T175A ICD1 Exon 6 c.475C4T R159X ICD1 DQ861347 Exon 8 c.748G4C A250P ICD2 DQ861349 Exon 9 c.837T4A Y279X ICD2 DQ861348 Exon 9 c.857C4T A286V ICD2 DQ861350 Exon 9 c.959C4T S320F TM5 Exon 10 c.1069T4C F357L ICD3 DQ861351 Exon 10 c.1091C4T A364V ICD3 DQ861352 Exon 11 c.1135_1136insAA S379KfsX413 ICD3 DQ861353 Exon 11 c.1207T4C Y403H NBD-NH2 A-loop EF035007 Exon 13 c.1424T4C V475A NBD-NH2 ter DQ861354 Exon 13 c.1531G4A A511T NBD-NH2 ter DQ861355 Exon 14 c.1672G4A E558K NBD-NH2 ter DQ861356 Exon 15 c.1769G4A R590Q NBD-NH2 ter Exon 15 c.1777A4G T593A NBD-NH2 ter DQ861357 Exon 15 c.1888A4G M630V NBD-NH2 ter DQ861358 Exon 17 c.2102T4C L701P Linker region DQ861359 Exon 17 c.2144C4T T715I TM7 DQ861360 Exon 17 c.2168G4A G723E TM7 DQ861361 Exon 17 c.2169_2170insG L724AfsX744 TM7 DQ861362 Exon 17 c.2176C4A P726T TM7 DQ861363 Exon 17 c.2210C4T A737V EC4 DQ861364 Exon 18 c.2284G4T G762X TM8 DQ861365 Exon 19 c.2324C4T T775M TM8 Exon 21 c.2519C4A A840D TM9 DQ861366 Exon 21 c.2662G4T E888X ICD5 DQ861367 Exon 23 c.2860G4A G954S TM11 DQ861368 Exon 27 c.3577G4A A1193T NBD-COOH ter DQ861369 a cDNA sequence is based on reference sequence GenBank NM_018849. Login to comment

[hide] BSEP and MDR3 haplotype structure in healthy Cauca... Hepatology. 2004 Mar;39(3):779-91. Pauli-Magnus C, Kerb R, Fattinger K, Lang T, Anwald B, Kullak-Ublick GA, Beuers U, Meier PJ
BSEP and MDR3 haplotype structure in healthy Caucasians, primary biliary cirrhosis and primary sclerosing cholangitis.
Hepatology. 2004 Mar;39(3):779-91., [PMID:14999697]

Abstract [show]
Primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC) are characterized by a cholestatic pattern of liver damage, also observed in hereditary or acquired dysfunction of the canalicular membrane transporters bile salt export pump (BSEP, ABCB11) and multidrug resistance protein type 3 (MDR3, ABCB4). Controversy exists whether a genetically determined dysfunction of BSEP and MDR3 plays a pathogenic role in PBC and PSC. Therefore, 149 healthy Caucasian control individuals (control group) were compared to 76 PBC and 46 PSC patients with respect to genetic variations in BSEP and MDR3. Sequencing spanned approximately 10,000 bp including promoter and coding regions as well as 50-350 bp of flanking intronic regions. In all, 46 and 45 variants were identified in BSEP and MDR3, respectively. No differences between the groups were detected either in the total number of variants (BSEP: control group: 37, PBC: 37, PSC: 31; and MDR3: control group: 35; PBC: 32, PSC: 30), or in the allele frequency of the common variable sites. Furthermore, there were no significant differences in haplotype distribution and linkage disequilibrium. In conclusion, this study provides an analysis of BSEP and MDR3 variant segregation and haplotype structure in a Caucasian population. Although an impact of rare variants on BSEP and MDR3 function cannot be ruled out, our data do not support a strong role of BSEP and MDR3 genetic variations in the pathogenesis of PBC and PSC.

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110 Five coding region changes were single nucleotide polymorphisms (synonymous: exon 4: C175T, exon 6: C504T, exon 8: A711T; nonsynonymous: exon 6: A523G 3 T175A and exon 16: A1954G 3 R652G). Login to comment

[hide] Sequence analysis of bile salt export pump (ABCB11... Pharmacogenetics. 2004 Feb;14(2):91-102. Pauli-Magnus C, Lang T, Meier Y, Zodan-Marin T, Jung D, Breymann C, Zimmermann R, Kenngott S, Beuers U, Reichel C, Kerb R, Penger A, Meier PJ, Kullak-Ublick GA
Sequence analysis of bile salt export pump (ABCB11) and multidrug resistance p-glycoprotein 3 (ABCB4, MDR3) in patients with intrahepatic cholestasis of pregnancy.
Pharmacogenetics. 2004 Feb;14(2):91-102., [PMID:15077010]

Abstract [show]
Intrahepatic cholestasis of pregnancy (ICP) is a liver disorder associated with increased risk of intrauterine fetal death and prematurity. There is increasing evidence that genetically determined dysfunction in the canalicular ABC transporters bile salt export pump (BSEP, ABCB11) and multidrug resistance protein 3 (MDR3, ABCB4) might be risk factors for ICP development. This study aimed to (i). describe the extent of genetic variability in BSEP and MDR3 in ICP and (ii). identify new disease-causing mutations. Twenty-one women with ICP and 40 women with uneventful pregnancies were recruited between April 2001 and April 2003. Sequencing of BSEP and MDR3 spanned 8-10 kb per gene and comprised the promoter region and 100-350 bp of the flanking intronic region around each exon. DNA sequencing of polymerase chain reaction fragments was performed on an ABI3700 capillary sequencer. MDR3 promoter activity of promoter constructs carrying different ICP-specific mutations was studied using reporter assays. A total of 37 and 51 variant sites were detected in BSEP and MDR3, respectively. Three non-synonymous sites in codons for evolutionarily conserved amino acids were specific for the ICP collective (BSEP, N591S; MDR3, S320F and G762E). Furthermore, four ICP-specific splicing mutations were detected in MDR3 [intron 21, G(+1)A; intron 25, G(+5)C and C(-3)G; and intron 26, T(+2)A]. Activity of the mutated MDR3 promoter was similar to that observed for the wild-type promoter. Our data further support an involvement of MDR3 genetic variation in the pathogenesis of ICP, whereas analysis of BSEP sequence variation indicates that this gene is probably less important for the development of pregnancy-associated cholestasis.

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115 Because T175A has already been detected in a larger cohort of healthy Caucasian volunteers [17], it cannot be counted as ICP-specific mutation, resulting in 15 (37.5%) and 11 (31.4%) variants specific for the ICP and the control group, respectively. Login to comment
142 Q R I K R I Q I D F H G I E H D T T E L H S I D D T L K I S E G I G D K R Q R K F F H A I L R G A V A G V T R I G G Q H L E K A Q K H L L G A E I F E YA R R T L I E G L S H A F K A H R D F H S H D Q D K H S T G A L A Q V Q G A T G T R L R S R H G A L L K R E I A E T A T S L T Q E R V Y H S E F L P Y R H S V Q K K I K D E L E A A G H E L A K A Y D A T Q G K K V Q E P I L I E A I S C Q Q R I A I E V V Q G L S L P A K L S H KL H A D T A L R T A K K A I H V V K E Y G K K F D A R V K Q Q R I L A P V F Q G G A V Q H T G H E Q H L K A A S C S S G V L L A Q L G I R H D G Y A G Q L S G G P R A H V P F G R S TT A D L L L I E I H A D L I Q I K Q A L L G V V H S F Y S L Q R E F L Q V T S K G K L H V Q H I D Q S V V E R V G D K H V V F H Y P V K E TE E D L A S T T I H R L S T A E S Y S D I D F K E L L L D G Q E A A K A A A V E L P K K Y F G H I T F E Y L A TE E V V K E S Q E R T C I V G D A L K R A H H I P I F A P L G V T K G L P K D Y F H D L E R H A T G H K P T S E L G I S S K F D G V T K T K K R K H I F R Y S D H Q L T L D K A A Q K A E G V F V D K G A T H F S S L S F H V H L L P K K H T R E E E F P I H A Y Y Y Y H T D S R G H K A I I E S K Q Q K C H I F VG P G D D A F R F C G H R F R D V G A HY L I V H G Y G H Q V F G I GE L H H P S G L G I A H A T T H G H S LFL G A G L A Y I A T L V L S P I I I G HT T V F H S I L F G A F I V G Q S A P C A F S LI L F L F I I S G F T F F L Q G F T F G F A T F V G H F V Y G S H L A F A A S Y Y L L I F I FV A F S P G L Q G I A H A T V C G A H L I A L I L S I S F H I Y A T L L L V F I A IS F G A V A LV H AG S S F G I T Q A F H Y F S Y A L L L V V A I I P V S A I V G A Q H G T G I I I S F I F V V YG I A H F Q Q F A G F I V G F I A K A Y E K D L S F A S L A E A R E A H E K G I K I K A ISAH I E E T D L D H R V T E H K K E S V K F Y V G D K A A T V A H R L S A L L EI K H P A H G H Q K S L D C L A Q V E A D F G A I V V Q G S H S S T Q H H S E F E L H R G R T T I A E E G EE H F L R S K R K L K H S Q H S T QQ QG ID A IVK K G G S L L E A T S Q D R I A I R Q P K I L L A H A V L A V E R G A G P K F D T L Q L E V A K K R I E Y A H A F H H T K D E V H C Y G R G I E E S V V G Q T S F L V P T I H L R E I Y D R H F H V I Q P Y L R Q D I I T G E D H D S T V Q L T G S G C G K S V K H L G K L V Q G S Q V T A R H V K I A V F S Y P S H D P H G E K L G K I S D H E KAGLHF QIIILS F S D I K P H H D I I D V P P V H A E L G D T E V F V I I A A G R A H A F A D P K V L K F H K T E H L R R S L Q T G A Q H IAL V I T S H A I G L L A A S H A V L V V V S Q H T F A A L S K E Y I K T175A E528D T775M R652G S Cytoplasm R T G762E S320F Extracellular K Fig. 2 Secondary structure of multidrug resistance protein 3 with non-synonymous coding region genetic variants. Login to comment

[hide] Expression and localization of hepatobiliary trans... Hepatology. 2005 May;41(5):1160-72. Keitel V, Burdelski M, Warskulat U, Kuhlkamp T, Keppler D, Haussinger D, Kubitz R
Expression and localization of hepatobiliary transport proteins in progressive familial intrahepatic cholestasis.
Hepatology. 2005 May;41(5):1160-72., [PMID:15841457]

Abstract [show]
Mutations of the bile salt export pump (BSEP) or the multidrug resistance P-glycoprotein 3 (MDR3) are linked to impaired bile salt homeostasis and lead to progressive familial intrahepatic cholestasis (PFIC)-2 and -3, respectively. The regulation of bile salt transporters in PFIC is not known. Expression of hepatobiliary transporters in livers of ten patients with a PFIC phenotype was studied by quantitative reverse transcription polymerase chain reaction, Western blotting, and immunofluorescence microscopy. PFIC was diagnosed by clinical and laboratory findings. All patients could be assigned to PFIC-2 or PFIC-3 by the use of BSEP- and MDR3-specific antibodies and by MDR3 gene-sequencing. Whereas in all PFIC-2 patients, BSEP immunoreactivity was absent from the canalicular membrane, in three PFIC-3 livers, canalicular MDR3 immunoreactivity was detectable. Serum bile salts were elevated to 276 +/- 233 and to 221 +/- 109 micromol/L in PFIC-2 and PFIC-3, respectively. Organic anion transporting polypeptide OATP1B1, OATP1B3, and MRP2 mRNA and protein levels were reduced, whereas sodium taurocholate cotransporting polypeptide (NTCP) was only reduced at the protein level, suggesting a posttranscriptional NTCP regulation. Whereas MRP3 mRNA and protein were not significantly altered, MRP4 messenger RNA and protein were significantly increased in PFIC. In conclusion, PFIC-2 may be reliably diagnosed by immunofluorescence, whereas the diagnosis of PFIC-3 requires gene-sequencing. Several mechanisms may contribute to elevated plasma bile salts in PFIC: reduced bile salt uptake via NTCP, OATP1B1, and OATP1B3, decreased BSEP-dependent secretion into bile, and increased transport back into plasma by MRP4. Upregulation of MRP4, but not of MRP3, might represent an important escape mechanism for bile salt extrusion in PFIC.

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38 Clinical and Laboratory Parameters of PFIC Patients Patients Clinical Parameters Laboratory Parameters Diagnosis Onset of Symptoms Age at LTx BS (<8 ␮M) ␥GT (<25 U/l) Bilirubin (<1 mg/dL) MDR3-Mutation MDR3- IF BSEP- IF PFIC Type C1 F.A. 4 m 3 y 5 m 47 7 1.3 None detected ϩ - 2 C2 A.A. 3 m 2 y 5 m 144 19 22.6 None detected ϩ - 2 C3 S.H. 3 m 3 y 3 m 616 77 22.7 None detected ϩ - 2 C4 M.D. 6 m 10 y 7 m 160 7 5.4 None detected ϩ - 2 C5 T.A. 6 m 4 y 2 m 414 11 5.4 555 A 3 G/T175A Heterozygous ϩ - 2 C6 M.D. 4 m 7 y 9 m 163 26 11.2 1069 G 3 T/S346I ϩ ϩ 3 C7 S.F. birth 8 y 7 m 299 250 1.9 1069 G 3 T/8346I* ϩ ϩ 3 C8 K.Y. 6 m 3 y 10 m 85 277 0.5 2890 C 3 A/A953D ϩ ϩ 3 C9 K.B. 4 m 3 y 8 m 360 165 1.1 426-432 del† - ϩ 3 C10 B.D. 7 y 11 y 4 m 199 24 20.7 None detected - ϩ 3 NOTE. Login to comment
185 (PFIC-2 patient C5) results in an amino acid change in codon 175 from threonine to alanine. Login to comment

[hide] Genetic variability, haplotype structures, and eth... Drug Metab Dispos. 2006 Sep;34(9):1582-99. Epub 2006 Jun 8. Lang T, Haberl M, Jung D, Drescher A, Schlagenhaufer R, Keil A, Mornhinweg E, Stieger B, Kullak-Ublick GA, Kerb R
Genetic variability, haplotype structures, and ethnic diversity of hepatic transporters MDR3 (ABCB4) and bile salt export pump (ABCB11).
Drug Metab Dispos. 2006 Sep;34(9):1582-99. Epub 2006 Jun 8., [PMID:16763017]

Abstract [show]
Biliary excretion of bile salts and other bile constituents from hepatocytes is mediated by the apical (canalicular) transporters P-glycoprotein 3 (MDR3, ABCB4) and the bile salt export pump (ABCB11). Mutations in ABCB4 and ABCB11 contribute to cholestatic diseases [e.g., progressive familial intrahepatic cholestasis 2 (PFIC2), PFIC3, and intrahepatic cholestasis of pregnancy], and our objective was to establish genetic variability and haplotype structures of ABCB4 and ABCB11 in healthy populations of different ethnic backgrounds. All coding exons, 5 of 6 noncoding exons, 50 to 300 base pairs of the flanking intronic regions, and 2.5 to 2.8 kilobase pairs of the promoter regions of ABCB4 and ABCB11 were sequenced in 159 and 196 DNA samples of Caucasian, African-American, Japanese, and Korean origin. In total, 76 and 86 polymorphisms were identified in ABCB4 and ABCB11, respectively; among them, 14 and 28 exonic polymorphisms, and 8 and 10 protein-altering variants, of which 4 were predicted to have functional consequences. Both genes showed substantial ethnic differences with respect to allele number, frequency of common and population-specific sites, and patterns of linkage disequilibrium. Population genetic analysis suggested some selective pressure against changes in the protein, supporting the important endogenous role of these transporters. Haplotype variability was greater in ABCB11 than in ABCB4. An ABCB11 promoter haplotype was associated with significant decrease of activity compared with wild type. Our results contribute to a better understanding of the molecular basis and of ethnic differences in drug response, and provide a valuable tool for future research on the heredity of cholestatic liver injury.

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177 Amino Acid Change Scoring Systems for Nonsynonymous Variants Grantham SIFT PolyPhen Blosum62 EC/EU MDR3 D87E 45 1.00 0.48 2 EC P95S 74 0.48 0.87 -1 EC T175A 58 0.01 0.72 -1 EC I367V 29 0.23 0.96 3 EC E450G 98 0.01 0.13 -2 EC R590Q 43 0.01 2.51 1 EC R652G 125 0.36 1.47 -2 EU E1099G 98 0.04 1.58 -2 EC BSEP I206V 29 1.00 0.23 3 EU V284A 64 0.13 0.43 -2 EC R299K 26 1.00 0.38 2 EU V444A 64 0.63 0.78 -2 EC R616G 125 0.01 3.16 -2 EC T619A 58 0.00 1.78 -1 EC M677V 21 0.29 0.82 1 EU R698H 29 0.30 0.57 0 EC A865V 64 0.02 1.12 0 EC R958Q 43 0.04 0.24 1 EU neutral mutation model (Tajima, 1989). Login to comment
63 The numbers 1 to 42 in the variant ID column indicate all variants included in haplotype analysis and linkage disequilibrium estimation. Variant ID 5Ј Sequence Genetic Variation 3Ј Sequence Region Amino Acid Change CA KO JA Total n % n % n % n % 43 TCAATGCAC g.-7676AϾT GTCTCACAA PromA 110 0.9 96 0.0 88 0.0 294 0.3 44 CTACCCTCT g.-7554TϾC CAATGCCTC PromA 110 0.9 96 0.0 88 0.0 294 0.3 45 GAGTGAAGT g.-7253GϾA TAGAAATCT PromA 106 0.0 96 1.0 94 0.0 296 0.3 46 AATTTAGAA g.-7114AϾT ACTCAATAG PromA 108 0.0 96 1.0 94 0.0 298 0.3 1 AAGAGGAAA g.-7094GϾC TTTCTTGTA PromA 108 13.0 96 30.2 94 24.5 298 22.1 47 CAAGAATTT g.-6816CϾT ATTAGGCAA PromA 102 0.0 96 1.0 92 0.0 290 0.3 48 GAGAGAGAG g.-6639AϾC GAGCTGAAT PromA 110 0.9 90 0.0 92 0.0 292 0.3 49 GAGAGAGAG g.-6637_-6636 delAG CTGAATCAG PromA 110 0.0 90 1.1 92 0.0 292 0.3 2 GTGCCTTTG g.-6588GϾT GTGTGCTGG PromA 110 2.7 88 0.0 92 2.2 290 1.7 3 AAAGAAGAA g.-6540CϾT GAAACCAAA PromA 108 14.8 86 26.7 90 27.8 284 22.5 4 TTAGTGACC g.-6325AϾG AAAGTTTGG PromA 108 17.6 90 31.1 92 26.1 290 24.5 5 ATTCTTTTT g.-6014GϾT TACAAACCC PromA 108 16.7 94 28.7 88 26.1 290 23.4 50 ACTGGTGCT g.-5941GϾA TGGGCACTA PromA 108 0.0 94 0.0 88 1.1 290 0.3 6 TGAAGTCAC g.-5859GϾA TGGCCAGAG PromA 108 16.7 94 28.7 88 26.1 290 23.4 7 ATGAGATGA g.-5717TϾC ATATATGTG PromA 110 0.0 92 1.1 86 3.5 288 1.4 8 CCTTCTTTA g.-5610TϾC ATGCCTAAA PromA 110 100.0 96 100.0 94 97.9 300 99.3 9 TAAGTGTGG g.-5570GϾC CAGCAATTA PromA 110 12.7 96 29.2 94 24.5 300 21.7 51 TACTCTCAC g.-5509GϾA GCTCTTATG PromA 110 0.0 96 1.0 94 0.0 300 0.3 10 CTCTCTTGT g.-5236CϾT TGAGTAATA PromA 108 15.7 90 27.8 94 26.6 292 22.9 52 GAGGATAAA g.-2551AϾT AAGAAAGAT PromB 126 0.0 88 0.0 90 1.1 304 0.3 11 AGCCTTACA g.-2478TϾG CAATGCATA PromB 126 4.8 88 0.0 90 2.2 304 2.6 12 GAAGGAATT g.-1921TϾC GGGTTGATT PromB/Exon -3 122 4.9 92 0.0 82 1.2 296 2.4 53 GAAGAGAAT g.-1899CϾA CTCATGGTC PromB/Exon -3 122 0.8 92 0.0 82 0.0 296 0.3 13 ATCCTAATA g.-1603AϾT CACCCTTAT PromB 128 0.0 94 2.1 86 1.2 308 1.0 14 TTTATAGAT g.-1584CϾT CAATGACTG PromB/Exon -2 118 11.0 94 29.8 74 23.0 286 20.3 54 ACACCAGGG g.-1510TϾG CCACCCAGC PromB 126 0.0 94 1.1 68 0.0 288 0.3 15 CTTATACCA g.-1484TϾC GCTCTGCTT PromB 126 0.0 94 1.1 68 5.9 288 1.7 55 TTTGAAAGT g.-1146CϾT TCCGGTTTC PromB 126 0.0 92 1.1 82 0.0 300 0.3 16 TGGTAGGAG g.-1031CϾT AGAGACAAT PromB 126 11.1 92 30.4 82 24.4 300 20.7 56 GAGACAATT g.-1020CϾG AATACAGAC PromB 126 0.0 92 1.1 82 0.0 300 0.3 17 ATTCAATAC g.-1014AϾG GACAGAAGT PromB 126 13.5 92 30.4 82 24.4 300 21.7 18 GAACTGGGG g.-682AϾC TGCGGAAGC PromB/Exon -1 124 1.6 70 0.0 64 0.0 258 0.8 19 AGGCTCCAG g.-495CϾG CTGATCTCG PromB 126 17.5 86 29.1 84 28.6 296 24.0 20 GCGCCCCGG g.-414CϾT GGCAAGAGC PromB 126 4.8 86 3.5 84 6.0 296 4.7 21 GGCAGGCTG g.-395CϾG GCCCCTGGC PromB 126 13.5 86 3.5 84 6.0 296 8.4 22 GCCCGCGCC g.-378TϾC AGCCTGGGG PromB 126 26.2 86 27.9 84 20.2 296 25.0 57 GCGTTTCCC g.-292GϾT GGCCGGACG PromB 128 0.0 96 0.0 92 1.1 316 0.3 58 CCGGACGCG g.-280CϾA GTGGGGGGC PromB 126 0.8 86 0.0 84 0.0 296 0.3 59 CCCTGCCAG g.-186AϾG CACGCGCGA PromB/Exon 1 128 0.0 96 1.0 92 0.0 316 0.3 23 TGCCCCCGG g.-75GϾT CCCCGCGAC PromB 128 0.0 96 0.0 92 1.1 316 0.3 24 TTTATGTCG g.12597CϾT TGGGTACCA Exon 4 L59L 126 12.7 96 25.0 94 21.3 316 19.0 60 CAAATTTGT g.12680TϾG GATACTGCA Exon 4 V86V 126 0.0 96 0.0 94 1.1 316 0.3 61 ATTTGTTGA g.12683TϾG ACTGCAGGA Exon 4 D87E 126 0.0 96 0.0 94 1.1 316 0.3 62 TTCTCCTTT g.12705CϾT CAGGTAAGC Exon 4 P95S 126 0.0 96 0.0 94 1.1 316 0.3 63 TAGCTTTCA g.20782TϾG ACATTTAAA Intron 4 114 0.0 88 1.1 70 0.0 272 0.4 25 TTTTAAAAA g.20813CϾT CTGGCAATG Intron 4 116 3.4 90 1.1 70 0.0 276 1.8 26 TCACCTATT g.21044AϾG TTATCATTT Intron 5 122 16.4 52 15.4 46 32.6 220 19.5 27 AAAAGAAAA g.22281_22284delGAAAA AAGAAAAGA Intron 5 126 7.9 88 0.0 84 0.0 298 3.4 28 TGACATCAA g.22490CϾT GACACCACT Exon 6 N168N 126 42.9 88 37.5 90 44.4 304 47.7 29 GAACTCAAT g.22509AϾG CGCGGCTAA Exon 6 T175A 126 3.2 88 0.0 90 0.0 304 1.3 64 CTCTGCAGC g.23831CϾT GTTTGGGCA Exon 7 A232A 128 0.0 94 0.0 90 1.1 312 0.3 65 AAGGGTTGA g.25313CϾG CAGAGTGCC Intron 7 124 0.8 96 0.0 90 0.0 310 0.3 30 TGTCCAGAT g.25376AϾT CTCTCGGCA Exon 8 I237l 126 15.1 96 27.1 90 27.8 312 22.4 66 GTTAATATA g.28354TϾC GCATCATAT Exon 9 Y309Y 128 0.8 96 0.0 92 0.0 316 0.3 67 GCATATGTG g.30584AϾG TCTTTGATA Exon 10 I367V 118 0.8 92 0.0 92 0.0 302 0.3 68 TAATATTTA g.31823TϾG AGGAATTCC Intron 11 128 0.0 96 0.0 92 1.1 316 0.3 31 ACTTTTTTT g.31941delT CAAATTTCA Intron 11 128 7.0 96 3.1 94 1.1 318 4.1 69 ACCCTGATG g.32140AϾG GGGCACAGT Exon 12 E450G 128 0.0 96 1.0 94 0.0 318 0.3 70 ACAAATTTG g.32232CϾT GTGTGAATC Intron 12 128 0.0 96 1.0 94 0.0 318 0.3 32 GGCAATGCC g.32277GϾT ATGGATAAT Intron 12 124 6.5 96 3.1 94 3.2 314 4.5 33 CAGCTATTA g.35024AϾG ATGGTTAAA Intron 12 124 95.2 94 70.2 94 72.3 312 80.8 71 ACAGGTAAA g.35273GϾA CCTCTGATA Intron 13 126 0.0 96 0.0 94 1.1 316 0.3 72 AGTGTGCCA g.43862AϾG TACTGTAAC Intron 14 122 0.8 88 0.0 72 0.0 282 0.4 34 TGTGCCAAT g.43864AϾG CTGTAACCC Intron 14 124 0.0 88 1.1 72 2.8 284 1.1 73 TAGCACACC g.43938GϾA ACTGTCTAC Exon 15 R590Q 124 0.8 88 0.0 74 0.0 286 0.3 35 GCTGCCACT g.48606AϾG GAATGGCCC Exon 16 R652G 124 7.3 86 2.3 74 1.4 284 4.2 36 GCTACAATT g.48771AϾG TTGAAATTC Intron 16 114 5.3 86 2.3 70 1.4 270 3.3 37 TTGCAAACA g.51576CϾT CACATAACA Intron 17 122 95.1 70 74.3 80 71.3 272 82.7 38 TTACATAAC g.56969AϾG TGGTTTTAG Intron 20 126 6.3 60 3.3 66 1.5 252 4.4 74 ATATTTTAC g.58304TϾC GTATTAATG Intron 21 124 0.0 96 0.0 92 1.1 212 0.3 39 CTGTATTAA g.58312TϾC GTCTAGAAC Intron 21 122 4.1 96 1.0 92 1.1 310 2.3 75 AAAGGAGGC g.63395delT GAAGAGATG Intron 22 124 0.8 92 0.0 94 0.0 310 0.3 76 AATATTAAG g.63598AϾT TTATTCTAT Intron 23 124 0.0 92 1.1 94 0.0 310 0.3 40 ATGGTCAAG g.68988AϾG AGCAAAGAA Exon 26 E1099G 112 1.8 92 0.0 84 0.0 288 0.7 41 TATTTATAA g.72169TϾC TTGGTTAAC Intron 26 122 91.8 90 65.6 92 75.0 304 78.9 42 GTAACATTT g.73092TϾC CAAATTTAC Intron 27 124 7.3 94 1.1 86 1.2 304 3.6 n, number of alleles analyzed (number of subjects times 2). 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110 These included three Caucasian variants in exon 6 (c.523AϾG; allele frequency 3.2%), exon 16 (c.1954AϾG; 7.3%), and exon 26 (c.3296AϾG; 1.8%), resulting in amino acid substitutions p.T175A, p.R652G, and p.E1099G, respectively. Login to comment
164 ABCB4 p.T175A (3.2%) and p.E1099G (1.8%) were only present in the Caucasian sample. Login to comment
271 Only two variants from our study had been related to cholestatic disease earlier, ABCB4 c.523AϾG (p.T175A), the second most prevalent nonsynonymous change in Caucasians (Rosmorduc et al., 2001), and the most prevalent nonsynonymous variant, ABCB4 c.1954GϾA (p.R652G), which was present in all of our population samples (Jacquemin et al., 2001). Login to comment

[hide] Mutations and polymorphisms in the bile salt expor... Pharmacogenet Genomics. 2007 Jan;17(1):47-60. Lang C, Meier Y, Stieger B, Beuers U, Lang T, Kerb R, Kullak-Ublick GA, Meier PJ, Pauli-Magnus C
Mutations and polymorphisms in the bile salt export pump and the multidrug resistance protein 3 associated with drug-induced liver injury.
Pharmacogenet Genomics. 2007 Jan;17(1):47-60., [PMID:17264802]

Abstract [show]
OBJECTIVES: Increasing evidence suggests that a genetically determined functional impairment of the hepatocellular efflux transporters bile salt export pump (BSEP, ABCB11) and multidrug resistance protein 3 (MDR3, ABCB4) play a pathophysiological role in the development of drug-induced liver injury. The aim of this study was therefore to describe the extent of genetic variability in ABCB11 and ABCB4 in patients with drug-induced liver injury and to in vitro functionally characterize newly detected ABCB11 mutations and polymorphisms. METHODS: ABCB11 and ABCB4 were sequenced in 23 patients with drug-induced cholestasis and 13 patients with drug-induced hepatocellular injury. Ninety-five healthy Caucasians served as the control group. Reference and mutant BSEP were expressed in Sf9 cells and ATP-dependent transport of [H]-taurocholate was measured in a rapid filtration assay. RESULTS: Four highly conserved nonsynonymous mutations were specific for drug-induced liver injury [ABCB11: D676Y (drug-induced cholestasis) and G855R (drug-induced cholestasis); ABCB4: I764L (drug-induced cholestasis) and L1082Q (drug-induced hepatocellular injury)]. Furthermore, a polymorphism in exon 13 of ABCB11 (V444A), which is associated with decreased hepatic BSEP expression was significantly more frequent in drug-induced cholestasis patients than in drug-induced hepatocellular injury patients and healthy controls (76 versus 50 and 59% in drug-induced cholestasis patients, drug-induced hepatocellular injury patients and healthy controls, respectively; P<0.05). The in-vitro transport activity of the V444A and the D676Y BSEP constructs was similar, whereas the G855R mutation was nonfunctional. CONCLUSION: In summary, our data support a role of ABCB11 and ABCB4 mutations and polymorphisms in drug-induced cholestasis. Genotyping of selected patients with acquired cholestasis might help to identify individuals with a genetic predisposition.

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149 Of the coding region changes, eight have previously been described in healthy Caucasians, including three synonymous and two nonsynonymous changes (synonymous: exon 4: 175C > T, exon 6: 504C > T, exon 8: 711A > T; nonsynonymous: exon 6: 523A > G-T175A, exon 15: 1769G > A-R590Q and exon 16: 1954A > G-R652G). Login to comment
163 The estimated IC50 was 50 and 60 mmol/l for reference BSEP Fig. 4 Extracellular I764L T175A R652G R590Q Cytoplasm L1082Q Secondary structure of multidrug resistance protein 3 (MDR3) with nonsynonymous coding region variants. Login to comment

[hide] Aspects of liver pathology in adult patients with ... Virchows Arch. 2012 Mar;460(3):291-8. Epub 2012 Feb 14. Wendum D, Barbu V, Rosmorduc O, Arrive L, Flejou JF, Poupon R
Aspects of liver pathology in adult patients with MDR3/ABCB4 gene mutations.
Virchows Arch. 2012 Mar;460(3):291-8. Epub 2012 Feb 14., [PMID:22331132]

Abstract [show]
The aims of this study were to describe the histological liver lesions in adult patients with MDR3/ ABCB4 mutation and to study the usefulness of MDR3 immunostaining as a diagnostic tool. All adult patients from our institution with an MDR3/ABCB4 mutation and a liver histology were included (n = 13). Eleven patients had a single heterozygous gene mutation and two patients had two heterozygous mutations. Two patients had no liver lesions. Eight patients had a mild ductular reaction and portal fibrosis. One patient had a few fibrous septa and two patients had biliary cirrhosis. In three cases intraductal lipid crystals were identified. Two patients had biliary fibroobliterative lesions with no sclerosing cholangitis on cholangiography. Biliary dysplasia was identified in hepatectomy specimens from two patients, one of whom developed an intrahepatic cholangiocarcinoma. One patient with biliary cirrhosis developed a hepatocellular carcinoma. MDR3 immunostainings performed on formalin-fixed paraffin-embedded sections showed a strong canalicular staining in all patients except in one. To conclude, the predominant histological features were ductular reaction with no or mild fibrosis without cholangitis. Liver lesions previously unreported in association with MDR3/ABCB4 gene mutations (biliary dysplasia, cholangiocarcinoma, small duct sclerosing cholangitis) were also found. Lipid crystals in bile ducts may be suggestive of MDR3/ABCB4 mutation. MDR3 immunostaining on formalin-fixed paraffin-embedded sections does not seem to be sensitive for the diagnosis of heterozygous MDR3/ABCB4 mutations.

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107 Location and nucleotide change Effect on protein Status of variant Mutation category 1 c.1328dup p.Arg444Glu fsX4, truncating Heterozygous Insertion 2 c.1584 G > C p.Glu528Asp Heterozygous Missense 3 c.101 C > T p.Thr34Met Heterozygous Missense 4 c.1553delT p.Leu518Tyr fsX16, truncating Heterozygous Deletion 5 c.139 C > G p.Arg 47 Gly Heterozygous Missense 6 c.1217 G > A p.Arg 406 Gln Heterozygous Missense c.140 G > A p.Arg47Gln Heterozygous, compound Missense 7 c.857 C > T p.Ala 286 Val Heterozygous Missense 8 c.2324 C > T p.Thr775Met Heterozygous Missense c.2836 G > A p.Ala946Thr Heterozygous Missense 9 c.523A > G p.Thr175Ala Heterozygous Missense 10 c.1005 + 5 G > A p.? Login to comment
108 Heterozygous Splicing 11 c.523A > G p.Thr175Ala Heterozygous Missense 12 c.959 C > T Ser 320 Phe Heterozygous Missense 13 c.959 C > T Ser 320 Phe Heterozygous Missense Fig. 1 Liver lesions in adult patients with MDR3 deficiency (MDR3/ABCB4 mutation). Login to comment
106 Location and nucleotide change Effect on protein Status of variant Mutation category 1 c.1328dup p.Arg444Glu fsX4, truncating Heterozygous Insertion 2 c.1584 G > C p.Glu528Asp Heterozygous Missense 3 c.101 C > T p.Thr34Met Heterozygous Missense 4 c.1553delT p.Leu518Tyr fsX16, truncating Heterozygous Deletion 5 c.139 C > G p.Arg 47 Gly Heterozygous Missense 6 c.1217 G > A p.Arg 406 Gln Heterozygous Missense c.140 G > A p.Arg47Gln Heterozygous, compound Missense 7 c.857 C > T p.Ala 286 Val Heterozygous Missense 8 c.2324 C > T p.Thr775Met Heterozygous Missense c.2836 G > A p.Ala946Thr Heterozygous Missense 9 c.523A > G p.Thr175Ala Heterozygous Missense 10 c.1005 + 5 G > A p.? Login to comment

[hide] Clinical features and genotype-phenotype correlati... J Pediatr Gastroenterol Nutr. 2011 Jan;52(1):73-83. Colombo C, Vajro P, Degiorgio D, Coviello DA, Costantino L, Tornillo L, Motta V, Consonni D, Maggiore G
Clinical features and genotype-phenotype correlations in children with progressive familial intrahepatic cholestasis type 3 related to ABCB4 mutations.
J Pediatr Gastroenterol Nutr. 2011 Jan;52(1):73-83., [PMID:21119540]

Abstract [show]
OBJECTIVES: The aim of the study was to estimate the frequency of ABCB4 mutations among children with chronic intrahepatic cholestasis with elevated gamma-glutamyl-transpeptidase (gamma-GT) activity and to characterize the genotypes with respect to severity of symptoms, response to ursodeoxycholic acid therapy, and outcome. PATIENTS AND METHODS: Molecular analysis of ABCB4 in 133 Italian children was performed, and ABCB4 mutations were classified as disease-causing mutations or benign substitutions according to the prediction algorithm PolyPhen. RESULTS: : Twenty-eight patients were identified carrying 31 mutations (20 disease causing). Twenty patients carried 2 mutated alleles and 8 only 1. At presentation (1-204 months), 20 children were symptomatic with jaundice and/or pruritus, whereas in 8 biochemical cholestasis was a fortuitous finding. Cirrhosis developed in 15 and 6 progressed to terminal liver failure. Disease-causing mutations on both alleles were found to be associated with reduced liver expression of ABCB4 protein, lack of response to ursodeoxycholic acid therapy, and progression to cirrhosis and end-stage liver disease, whereas mild genotypes, including single heterozygous mutations, were generally associated with less severe disease and, often, absence of symptoms. CONCLUSIONS: ABCB4 mutations are responsible for a chronic liver disease in more than one-third of patients with chronic intrahepatic cholestasis and elevated gamma-GT activity. In patients with severe ABCB4 genotype, the disease is often progressive with risk of developing cirrhosis and liver failure during the first 2 decades of life. Patients with mild genotypes, including single heterozygous mutations, have variable expressions of liver disease that may be influenced by comorbidity factors and modulated by still unknown genetic modifiers.

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107 Nucleotidechange (effectonprotein) Predictionscoresby PolyPhenanalysis Nucleotidechange (effectonprotein) Predictionscoresby PolyPhenanalysis Referencefor eachgenotype 1[1-I]c.475C>T(p.R159X)XUnknownUnknown20 1[1-II]c.475C>T(p.R159X)XUnknownUnknownThisstudy 2[2-I]c.523A>G(p.T175A)0.774c.1069T>C(p.F357L)þc.2324C>T(p.T775M)1.079þ0.59720 3[3-I]c.1135_1136insAA(p.S379KfsX413)Xc.2102T>C(p.L701P)2.22620 4[4-I]c.2662G>T(p.E888X)Xc.748G>C(p.A250P)Rc.1888A>G(p.M630V)1.871R1.67720 5[5-I]c.959C>T(p.S320F)1.287c.857C>T(p.A286V)1.40820 6[6-I]c.377G>A(p.G126E)1.998c.1531G>A(p.A511T)2.1720 6[6-II]c.377G>A(p.G126E)1.998c.1531G>A(p.A511T)2.1720 7[7-I]c.2176C>A(p.P726T)2.086c.1769G>A(p.R590Q)þc.2284G>T(p.G762X)2.623RX20 8[8-1]c.1091C>T(p.A364V)1.343c.2210C>T(p.A737V)0.21720 9[9-I]c.1777A>G(p.T593A)2.044UnknownUnknown20 10[10-I]c.2144C>T(p.T715I)0.383UnknownUnknown20 11[11-I]c.2519C>A(p.A840D)1.803c.1424T>C(p.V475A)2.60320 12[12-I]c.1672G>A(p.E558K)2.486c.2168G>A(p.G723E)Rc.3577G>A(p.A1193T)1.548þ2.34120 12[12-II]c.1672G>A(p.E558K)2.486c.2168G>A(p.G723E)Rc.3577G>A(p.A1193T)1.548þ2.34120 13[13-I]c.2860G>A(p.G954S)0.245c.2860G>A(p.G954S)0.24520 14[14-I]c.523A>G(p.T175A)0.774UnknownUnknown20 15[15-I]c.959C>T(p.S320F)1.287c.837T>A(p.Y279X)X20 16[16-I]c.523A>G(p.T175A)0.774UnknownUnknown20 17[17-I]c.2169_2170insG(p.L724AfsX744)Xc.2169_2170insG(p.L724AfsX744)X20 17[17-II]c.2169_2170insG(p.L724AfsX744)Xc.2169_2170insG(p.L724AfsX744)X20 18[18-I]c.1207T>C(p.Y403H)2.798c.1207T>C(p.Y403H)2.79820 19[19-I]c.208G>C(p.G70R)þc.1769G>A(p.R590Q)1.497þ2.623c.959C>T(p.S320F)1.287Thisstudy 19[19-II]c.208G>C(p.G70R)þc.1769G>A(p.R590Q)1.497þ2.623c.959C>T(p.S320F)1.287Thisstudy 19[19-III]c.208G>C(p.G70R)þc.1769G>A(p.R590Q)1.497þ2.623c.959C>T(p.S320F)1.287Thisstudy 20[20-I]c.217C>G(p.L73V)0.489UnknownUnknown22,thisstudy 21[21-I]c.959C>T(p.S320F)1.287c.959C>T(p.S320F)1.28716,thisstudy 22[22-I]c.1207T>C(p.Y403H)2.798UnknownUnknownThisstudy Xidentifiesmutationsthatpredictprematureterminationoftranslation.PolyPhenpredictionwithPSICscoredifferencesbelow1.5definebenignsubstitutions;PSICscoredifferencesencompassing between1.5and2.0(bold)definesubstitutionspossiblydamaging,whereasabove2.0(underlined)definesubstitutionsprobablydamaging. Login to comment

[hide] ABCB4 deficiency: A family saga of early onset cho... Hepatol Res. 2010 Sep;40(9):937-41. Denk GU, Bikker H, Lekanne Dit Deprez RH, Terpstra V, van der Loos C, Beuers U, Rust C, Pusl T
ABCB4 deficiency: A family saga of early onset cholelithiasis, sclerosing cholangitis and cirrhosis and a novel mutation in the ABCB4 gene.
Hepatol Res. 2010 Sep;40(9):937-41., [PMID:20887599]

Abstract [show]
Gallstones are very common. However, there is a small group of patients with low phospholipid-associated cholelithiasis (LPAC) that is characterized by symptomatic cholelithiasis at a young age (<40 years), recurrence of biliary symptoms despite cholecystectomy and concrements or sludge in the intra- and extrahepatic biliary system. The LPAC syndrome is associated with mutations of the adenosine triphosphate-binding cassette, subfamily B, member 4 (ABCB4) gene encoding the hepatobiliary phospholipid translocator multidrug resistance protein 3 (MDR3). Impairment of MDR3 leads to a reduction of biliary phosphatidyl choline levels resulting in a lithogenic and toxic bile. This causes recurrent cholelithiasis, continuous irritations of the biliary tract with cholangitis, chronic cholestasis and even biliary cirrhosis. Here we report on a family with ABCB4 deficiency and LPAC syndrome associated with a novel mutation (c.3203T>A) in the ABCB4 gene.

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27 The patient was heterozygous for the mutations c.523A>G and c.3203T>A in the ABCB4 gene on chromosome 7q21.1, resulting in a p.Thr175Ala and a p.Val1068Glu amino acid change of the encoded protein, the hepatic phospholipid translocator MDR3, in accordance with the diagnosis of ABCB4 deficiency. Login to comment
58 The other mutation c.523A>G results in a p.Thr175Ala amino acid change. There is a small physicochemical difference between threonine and glutamic acid (Grantham distance 58 [normal 0-215]). Login to comment

[hide] An MBL2 haplotype and ABCB4 variants modulate the ... Dig Liver Dis. 2009 Nov;41(11):817-22. Epub 2009 May 20. Tomaiuolo R, Degiorgio D, Coviello DA, Baccarelli A, Elce A, Raia V, Motta V, Seia M, Castaldo G, Colombo C
An MBL2 haplotype and ABCB4 variants modulate the risk of liver disease in cystic fibrosis patients: a multicentre study.
Dig Liver Dis. 2009 Nov;41(11):817-22. Epub 2009 May 20., [PMID:19467940]

Abstract [show]
BACKGROUND: Cystic fibrosis is the most common lethal recessive disorder among Caucasians. Over 1500 mutations have been identified in cystic fibrosis transmembrane conductance regulator disease-gene so far. A large variability of the clinical phenotype has been observed both in cystic fibrosis patients bearing the same genotype, and in affected sibpairs. Thus, genes inherited independently from cystic fibrosis transmembrane conductance regulator could modulate the clinical expression of cystic fibrosis. METHODS: We analysed some putative modifier genes of liver cystic fibrosis phenotype (serpin 1, hemochromatosis, transferrin receptor 2, ferroportin 1, mannose binding lectin and adenosine triphospate-binding cassette subfamily B member 4) in 108 unrelated cystic fibrosis patients with and without liver involvement. RESULTS: HYPD mannose binding lectin haplotype was significantly (p<0.05) more frequent in cystic fibrosis patients with liver disease versus those without liver disease. This haplotype already related to a more severe pulmonary cystic fibrosis phenotype, is associated to a reduced MBL immunological activity. The c.834-66G>T variant of adenosine triphospate-binding cassette subfamily B member 4 gene was significantly (p<0.05) less frequent in cystic fibrosis patients with liver disease as compared to those with no liver disease. CONCLUSIONS: The HYPD mannose binding lectin haplotype may predispose a subgroup of cystic fibrosis patients to a more severe liver involvement impairing the local defence mechanisms whereas the c.834-66G>T adenosine triphospate-binding cassette subfamily B member 4 variant may enhance the activity of the protein and thus exert a protective effect toward liver disease.

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75 Among them, we observed the already described hypomorphic allele c.523A>G (p.T175A) in heterozygous state in two CF patients with cirrhosis. Login to comment
112 Among these the hypomorphic allele c.523A>G (p.T175A), the most common ABCB4 mutation, segregates with two CF patients with cirrhosis, and is absent in all CF patients without liver disease. Login to comment
114 Indeed, the ABCB4 allele p.T175A has been recently reported as a disease-causing mutation in three subjects with PFIC3 phenotype [24]. Login to comment
115 Further studies on a larger number of patients are needed to establish the role of p.T175A allele in predisposing to liver disease in CF patients. Login to comment
74 Among them, we observed the already described hypomorphic allele c.523A>G (p.T175A) in heterozygous state in two CF patients with cirrhosis. Login to comment
111 Among these the hypomorphic allele c.523A>G (p.T175A), the most common ABCB4 mutation, segregates with two CF patients with cirrhosis, and is absent in all CF patients without liver disease. Login to comment
113 Indeed, the ABCB4 allele p.T175A has been recently reported as a disease-causing mutation in three subjects with PFIC3 phenotype [24]. Login to comment

[hide] ABCB4 sequence variations in young adults with cho... Liver Int. 2009 May;29(5):743-7. Epub 2008 Oct 24. Nakken KE, Labori KJ, Rodningen OK, Nakken S, Berge KE, Eiklid K, Raeder MG
ABCB4 sequence variations in young adults with cholesterol gallstone disease.
Liver Int. 2009 May;29(5):743-7. Epub 2008 Oct 24., [PMID:19018976]

Abstract [show]
BACKGROUND AND AIMS: Mutations in the gene encoding the ABCB4 [adenosine triphosphate (ATP)-binding cassette, sub-family B (MDR/TAP), member 4] transporter lower phosphatidylcholine output into bile and contribute to cholesterol gallstone formation by decreasing the solubility of cholesterol in bile. Mutations in ABCB4 have been identified in patients with low phospholipid-associated cholelithiasis. The aim of the present study was to determine the types and frequencies of ABCB4 mutations in cholecystectomized patients aged <40 years. PATIENTS AND METHODS: Hundred and four patients (mean age 30.6 years, range 12-39) were included in the study and the ABCB4 gene was sequenced. The frequency of missense mutations found in the patient material was measured in 95 healthy controls. The potential functional implications of the ABCB4 missense variations were assessed by computerized analysis (BLOSUM62 and Grantham substitution matrices, polymorphism phenotyping and sorting intolerant from tolerant). RESULTS: One patient was heterozygous for a frameshift mutation (c.1399_1400ins10/p.Y467F fsX25). Another patient was heterozygous for a nonsense mutation (c.3136C>T/p.R1046X). These two mutations are considered detrimental to ABCB4 protein function. In addition, six missense mutations were found in the ABCB4 gene, and three of these were only present in patients. CONCLUSION: In our study, <2% of young gallstone patients were found to be heterozygous for detrimental ABCB4 mutations. The functional implication of several missense mutations remains to be clarified. Thus, mutations in the ABCB4 gene are a rare cause of gallstone disease.

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62 These were c.337A4G/p.M113L, c.523A4G/p.T175A, c.1584G4 C/ p.E528D, c.1769G4 A/p.R590Q, c.1954A4G/p.R652G and c.3318G4 C/p.Q1106H). Login to comment
78 Six patients and three controls were heterozygous for c.523A4G in exon 6, which changed residue 175 from threonine to alanine (p.T175A). Login to comment
88 Table 1. Summary of patient characteristics having ABCB4 gene variations with possible effects on the ABCB4 protein and the occurrence of these variations in healthy controls Patient (ID) (n = 104) Gender/ethnicity Age Indication for surgery Gallstone Location Nucleotide change Peptide change Status Controls (n = 95) 1-16 Female Exon 16 c.1954A 4 G p.R652G 9 17-22 Female/Norwegian 21 Choledocholithiasis Multiple, 5 mm Exon 6 c.523A 4 G p.T175A heterozygous 3 Female/Iraq 25 Cholecystolithiasis Multiple, 5-10 mm Female/Norwegian 28 Cholecystolithiasis Two, 15 mm Female/African 31 Cholecystitis Multiple, 5 mm1solitary, 20 mm Female/Norwegian 32 Cholecystolithiasis Multiple, 5 mm Female/Norwegian 34 Cholecystolithiasis Multiple, 5-10 mm 23 Female/Norwegian 32 Cholecystolithiasis Two, 20 mm Exon 14 c.1584G 4 C p.E528D heterozygous 0 24-25 Female/Norwegian 23 Cholecystolithiasis Multiple, 5 mm Exon 15 c.1769G 4 A p.R590Q heterozygous 1 Female/Norwegian 37 Cholecystolithiasis Multiple, o 5 mm 26 Female/Norwegian 40 Cholecystitis Solitary, 30 mm Exon 25 c.3136C 4 T p.R1046X heterozygous - 27 Female/Pakistani 30 Cholecystolithiasis Three, 10 mm Exon 13 c.1399_1400 ins10 p.Y467F fsX25 heterozygous - 28 Ã Female/Pakistani 32 Cholecystolithiasis Multiple, o 5 mm Exon 5 c.337A 4 G p.M113L heterozygous 0 Exon 26 c.3318G 4 C p.Q1106H 0 The variation p.R652G, considered to be without functional significance for the ABCB4 product, is shown without patient characteristics (16 patients). Login to comment
94 Grantham values range from 5 to 215; low values ( o 50) indicate chemical similarity and high values ( 4 50) indicate more radical differences) Scoring Systems for Nonsynonymous Variants Amino acid change Grantham Blosum62 SIFT PolyPhen EC/EU p.M113L 15 2 0.17 1.211 EC p.T175A 58 0 0 0.845 EC p.E528D 45 2 0.25 0.617 EC p.R590Q 43 1 0 1.951 EC p.R652G 125 À 2 0.42 1.237 EU p.Q1106H 24 0 0.03 0.185 EC Blosum62 values range from À 4 to13, with negative values indicating less acceptable and positive values indicating more acceptable substitutions. Login to comment
115 Six patients were found to have the variation c.523A 4G (p.T175A), resulting in an allele frequency of 6/208 (2.9%). Login to comment
117 p.T175A has already been detected in a larger cohort of Caucasian volunteers (17, 18). Login to comment

[hide] ABCB4 heterozygous gene mutations associated with ... Gastroenterology. 2008 Jul;135(1):131-41. Epub 2008 Mar 26. Ziol M, Barbu V, Rosmorduc O, Frassati-Biaggi A, Barget N, Hermelin B, Scheffer GL, Bennouna S, Trinchet JC, Beaugrand M, Ganne-Carrie N
ABCB4 heterozygous gene mutations associated with fibrosing cholestatic liver disease in adults.
Gastroenterology. 2008 Jul;135(1):131-41. Epub 2008 Mar 26., [PMID:18482588]

Abstract [show]
BACKGROUND & AIMS: Adenosine triphosphate-binding cassette subfamily B, member 4 (ABCB4) mutations have not been investigated in patients with unexplained cholestasis. We aimed to investigate ABCB4 mutations in adult patients with unexplained anicteric cholestasis and to describe liver injury associated with ABCB4 mutations. METHODS: Between February 2004 and March 2007, all adults with unexplained cholestasis despite multiple investigations including liver biopsy and 124 healthy volunteers had ABCB4 sequencing. Fibrosis, bile duct lesions, inflammatory infiltrate, activation of myofibroblasts and multidrug-resistant P-glycoprotein 3 (MDR3) immunostaining were assessed on patients' liver biopsy specimens. RESULTS: Thirty-two patients were included (23 females, 16-69 years of age). Eight different ABCB4 heterozygous mutations were found in 11 patients (34%). Seven of these mutations (exons 4, 6, 14, 18, 23) were never detected in the control group. One mutation (exon 15) was detected in 4 patients (12.5%) and 4 controls (3%). At the time of liver biopsy, the main clinical and biologic characteristics were similar in the 32 patients regardless of ABCB4 mutation. The histologic pattern in patients with a mutation consisted of portal fibrosis with ductular reaction and strong macrophagic infiltrate of portal tracts without significant periportal and lobular necroinflammatory lesions or cholangitis. Fibrosis score and macrophagic infiltration of portal tracts were significantly increased in patients with ABCB4 mutation (P = .01). Absence or reduced MDR3 canalicular immunostaining was demonstrated in all patients with ABCB4 mutations tested. CONCLUSIONS: Heterozygous ABCB4 mutations were detected in 34% of adults with unexplained cholestasis, for the most part without biliary symptoms, and could result in significant liver fibrosis.

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56 As described in Figure 1, 3 (T175A, R590Q, A934T) have been previously described in patients with LPAC or ICP.8,13 Conversely, 5 (R47X, V526F, A539T, R545G, I738L) have not been previously described.20 The frequency of each mutation is indicated in Figure 1. Login to comment
91 Clinical Characteristics at the Time of Liver Biopsy and ABCB4 Heterozygous Point Mutations Identified in 11 Patients With Unexplained Anicteric Cholestasis Case Sex Age Cholelithiasis symptoms (age at the onset) Recurrence of cholelithiasis after cholecystectomy Intrahepatic hyperechogenic foci, sludge, or microlithiasis ICPa or steroid sexual triggered cholestasisb ABCB heterozygous mutation Exon Location and nucleotide changes Amino acid changes 1 F 23 No __ No Yesa Nonsense 4c c. 139CϾT R47X Missense 6 c. 523AϾG T175A 2 F 16 No - No Yesb Nonsense 4c c. 139CϾT R47X Missense 6 c. 523AϾG T175A 3 F 50 No - No No Missense 18c c. 2212AϾC I738L 4 M 53 Yes (53 y) No Yes - Missense 14c c. Login to comment
92 1615GϾA A539T Missense 15 c. 1769GϾA R590Q 5 F 47 No - No No Missense 23 c. Login to comment
57 As described in Figure 1, 3 (T175A, R590Q, A934T) have been previously described in patients with LPAC or ICP.8,13 Conversely, 5 (R47X, V526F, A539T, R545G, I738L) have not been previously described.20 The frequency of each mutation is indicated in Figure 1. Login to comment

[hide] Low phospholipid associated cholelithiasis: associ... Orphanet J Rare Dis. 2007 Jun 11;2:29. Rosmorduc O, Poupon R
Low phospholipid associated cholelithiasis: association with mutation in the MDR3/ABCB4 gene.
Orphanet J Rare Dis. 2007 Jun 11;2:29., [PMID:17562004]

Abstract [show]
Low phospholipid-associated cholelithiasis (LPAC) is characterized by the association of ABCB4 mutations and low biliary phospholipid concentration with symptomatic and recurring cholelithiasis. This syndrome is infrequent and corresponds to a peculiar small subgroup of patients with symptomatic gallstone disease. The patients with the LPAC syndrome present typically with the following main features: age less than 40 years at onset of symptoms, recurrence of biliary symptoms after cholecystectomy, intrahepatic hyperechoic foci or sludge or microlithiasis along the biliary tree. Defect in ABCB4 function causes the production of bile with low phospholipid content, increased lithogenicity and high detergent properties leading to bile duct luminal membrane injuries and resulting in cholestasis with increased serum gamma-glutamyltransferase (GGT) activity. Intrahepatic gallstones may be evidenced by ultrasonography (US), computing tomography (CT) abdominal scan or magnetic resonance cholangiopancreatography, intrahepatic hyperechogenic foci along the biliary tree may be evidenced by US, and hepatic bile composition (phospholipids) may be determined by duodenoscopy. In all cases where the ABCB4 genotyping confirms the diagnosis of LPAC syndrome in young adults, long-term curative or prophylactic therapy with ursodeoxycholic acid (UDCA) should be initiated early to prevent the occurrence or recurrence of the syndrome and its complications. Cholecystectomy is indicated in the case of symptomatic gallstones. Biliary drainage or partial hepatectomy may be indicated in the case of symptomatic intrahepatic bile duct dilatations filled with gallstones. Patients with end-stage liver disease may be candidates for liver transplantation.

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46 To date, two of the missense mutations (Glu528Asp and Thr175Ala) detected in patients with the LPAC syndrome had been analyzed previously in a homolog of ABCB4 (Pgp now called ABCB1) in yeast [13,14]. Login to comment
47 The Thr175Ala mutation was localized in the 1st intracellular loop and resulted in a substitution in a conserved cluster of four amino-acids at position 169-172, required for the adenosine triphosphatase activity of the molecule. Login to comment
53 It should be noted that the two unrelated patients in whom the Thr175Ala mutation was identified originated from Northern Europe, so they may have inherited a founder mutation from a shared ancestor. Login to comment

[hide] Function and pathophysiological importance of ABCB... Pflugers Arch. 2007 Feb;453(5):601-10. Epub 2006 Apr 19. Oude Elferink RP, Paulusma CC
Function and pathophysiological importance of ABCB4 (MDR3 P-glycoprotein).
Pflugers Arch. 2007 Feb;453(5):601-10. Epub 2006 Apr 19., [PMID:16622704]

Abstract [show]
Like several other ATP-binding cassette (ABC) transporters, ABCB4 is a lipid translocator. It translocates phosphatidylcholine (PC) from the inner to the outer leaflet of the canalicular membrane of the hepatocyte. Its function is quite crucial as evidenced by a severe liver disease, progressive familial intrahepatic cholestasis type 3, which develops in persons with ABCB4 deficiency. Translocation of PC makes the phospholipid available for extraction into the canalicular lumen by bile salts. The primary function of biliary phospholipid excretion is to protect the membranes of cells facing the biliary tree against these bile salts: the uptake of PC in bile salt micelles reduces the detergent activity of these micelles. In this review, we will discuss the functional aspects of ABCB4 and the regulation of its expression. Furthermore, we will describe the clinical and biochemical consequences of complete and partial deficiency of ABCB4 function.

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141 Canalicular lipid transport defects can cause gallstone formation Cholesterol supersaturation of bile, which occurs in a large proportion of humans, leads to the formation of cholesterol Walker B; L556R 571del Truncation PFIC3 LPAC ICP 27 splice Truncation 132 del Truncation TM 2; W138R TM 12; 981 del Truncation Linker; Q636X Truncation TM 11; R957X Truncation TM 6; S346I E395G Walker B; I541F TM 12; G983S Walker A; V425M Walker A; T424A Walker B; D564G TM 7; F711S 180 del truncation 336 delT truncation Exon 22-23 del truncation F165I T175A TM 5; M301T TM 5; S320F 336 insT truncation Walker A; 432 insA truncation E528D L591Q W658stop 757 insT R788E A934T P1161S TM 5; S320F TM 8; G762ER144X Walker B; A546D Walker B; G535AALL 96 del Truncation Walker B; L556R 571del Truncation PFIC3 LPAC ICP 27 splice Truncation 132 del Truncation TM 2; W138R TM 12; 981 del Truncation Linker; Q636X Truncation TM 11; R957X Truncation TM 6; S346I E395G Walker B; I541F TM 12; G983S Walker A; V425M Walker A; T424A Walker B; D564G TM 7; F711S 180 del truncation 336 delT truncation Exon 22-23 del truncation F165I T175A TM 5; M301T TM 5; S320F 336 insT truncation Walker A; 432 insA truncation E528D L591Q W658stop 757 insT R788E A934T P1161S TM 5; S320F TM 8; G762ER144X Walker B; A546D Walker B; G535AALL 96 del Truncation Fig. 3 Summary of the known mutations and their localization in the protein, as identified in patients with PFIC type 3, LPAC syndrome (intrahepatic gallstone formation), and intrahepatic cholestasis of pregnancy (ICP). Login to comment

[hide] ABCB4 gene mutation-associated cholelithiasis in a... Gastroenterology. 2003 Aug;125(2):452-9. Rosmorduc O, Hermelin B, Boelle PY, Parc R, Taboury J, Poupon R
ABCB4 gene mutation-associated cholelithiasis in adults.
Gastroenterology. 2003 Aug;125(2):452-9., [PMID:12891548]

Abstract [show]
BACKGROUND & AIMS: We recently put forward arguments in favor of ABCB4 gene (adenosine triphosphate-binding cassette, subfamily B, member 4) defects as a risk factor for symptomatic cholelithiasis in adults. In this study, we characterized ABCB4 gene mutations in a series of patients with symptomatic cholelithiasis to determine the genetic basis and the clinical phenotype of ABCB4 gene mutation-associated cholelithiasis. METHODS: We analyzed the entire ABCB4 gene coding sequences in a first group of 32 patients who had a clinical history compatible with the syndrome previously described, in a second group of 28 patients who presented with a classic gallstone disease that justified a cholecystectomy, and in a third group of 33 patients without a history of cholelithiasis. RESULTS: We identified both heterozygous and homozygous ABCB4 gene point mutations in 18 of 32 (56%) patients who presented with clinical criteria of the syndrome, whereas no mutation was detected in the 2 other groups of patients (P < 0.001). Three independent clinical features were strongly associated with point mutations: recurrence of symptoms after cholecystectomy (odds ratio, 8.5); intrahepatic hyperechoic foci, intrahepatic sludge, or microlithiasis (odds ratio, 6.1); and age <40 years at the onset of symptoms (odds ratio, 3.0). ABCB4 gene point mutations were detected exclusively in the patients who showed 2 or 3 of these clinical features. CONCLUSIONS: Our results show that ABCB4 gene mutations represent a major genetic risk factor in a symptomatic and recurring form of cholelithiasis in young adults.

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68 ABCB4 Gene Mutations in Patients With LPAC Syndrome Gene position Location and nucleotide change Peptide change Protein domain Status 6 495T3A Phe165Ile First intracellular loop Heterozygous 523T3C Thr175Ala between TM2 and TM3 Heterozygous 9 902T3C Met301Thr TM5 Heterozygous 959C3T Ser320Phe TM5 Homozygous 10 1007-1015insT 355Stop TM6 Heterozygous 1007-1015delT 341Stop TM6 Heterozygous 12 1327insA 447Stop Close to NBD11 Heterozygous 14 1584G3C Glu528Asp Close to NBD11 Heterozygous 15 1772T3A Leu591Gln Third intracellular loop Homozygous 17 1973G3A Try658Stop Third intracellular loop linker domain Heterozygous 18 2270-2273insT 793Stop Fourth intracellular loop between TM8 and TM9 Heterozygous 19 2363G3T Arg788Glu Fourth intracellular loop between TM8 and TM9 Heterozygous 23 2800G3T Ala934Thr Fifth intracellular loop between TM10 and TM11 Homozygous 26 3481C3T Pro1161Ser Close to NBD2 Heterozygous NOTE. The A of ATG of the initiator Met codon was denoted as "nucleotide ϩ 1." Login to comment
96 Two of the missense mutations (Thr175Ala and Glu528Asp) detected in the patients with the LPAC syndrome were analyzed previously in yeast.23,24 The Thr175Ala mutation was localized in the first intracellular loop and resulted in a substitution in a conserved cluster of 4 amino acids at position 169-172, which is required for the adenosine triphosphatase activity of the molecule. Login to comment
102 The 2 unrelated patients in whom the Thr175Ala mutation was identified originated from Northern Europe, so they may have inherited a founder mutation from a shared ancestor. Login to comment

[hide] ABCB4 and ABCB11 mutations in intrahepatic cholest... Dig Liver Dis. 2013 Mar;45(3):226-32. doi: 10.1016/j.dld.2012.08.011. Epub 2012 Sep 27. Anzivino C, Odoardi MR, Meschiari E, Baldelli E, Facchinetti F, Neri I, Ruggiero G, Zampino R, Bertolotti M, Loria P, Carulli L
ABCB4 and ABCB11 mutations in intrahepatic cholestasis of pregnancy in an Italian population.
Dig Liver Dis. 2013 Mar;45(3):226-32. doi: 10.1016/j.dld.2012.08.011. Epub 2012 Sep 27., [PMID:23022423]

Abstract [show]
BACKGROUND: Genetic alterations in the ATP-binding cassette subfamily B member 4 (ABCB4) and ATP-binding cassette subfamily B member 11 (ABCB11) have been associated to the onset of intrahepatic cholestasis of pregnancy (ICP) in predisposed women. AIMS: To identify new and/or frequent ABCB4 and ABCB11 genes variants in a cohort of Italian patients with ICP and to evaluate the possible pathogenetic role for the novel mutations identified. METHODS: DNA of 33 unrelated Italian women with obstetric cholestasis were screened for mutations in the entire coding sequence of ABCB4 and ABCB11 genes. Polymerase chain reaction and automated sequencing was performed on the 27 coding exons of both genes. RESULTS: Genotyping revealed 11 mutations, 5 of whom were novel variants: 2 localized on ABCB4 (p.I587DfsX603, p.I738LfsX744) and 3 on ABCB11 (p.V284D, p.Q558H, p.P731S). The most severe phenotypes were associated with the variants p.I587DfsX603, p.I738LfsX744 and p.V284D. Moreover, the already described mutation p.N510S found in ABCB4 seems to be strictly involved in the onset of ICP in that particular patient. CONCLUSIONS: Our data support the hypothesis of a significant involvement of ABCB4 mutations in the onset of ICP, but also confirm an important role for ABCB11 mutations in increasing the susceptibility to cholestasis of pregnancy.

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69 The p.L73V, the p.T175A and the p.N510S were previously described in literature [12,24]. Login to comment
101 Nucleotide change and effect on protein Location PSIC scores by PolyPhen-2 analysis Reference 1 c.217 C > G (p. L73V) Exon 4 0.489 [12] 2 c.523 A > G (p.T175A) Exon 6 0.774 [12] 3 c.1529 A > G (p.N510S) Exon 13 2.075 [24] 4 c.1758 1759 ins G (p.I587DfsX603) Exon 15 X This study 5 c.2211(+1) G > T (p.I738LfsX744) 5 Intron 17 X This study ABCB11 mutations 6 c.403 G > A (p.E135K) Exon 6 0.502 [26] 7 c.852 T > A (p.V284D) Exon 9 2.175 This study 8 c.1445 A > G (p.D482G) Exon 14 1.364 [26-28] 9 c.1674 G > C (p.Q558H) Exon 15 1.383 This study 10 c.2093 G > A (p.R698H) Exon 18 0.821 [12,25] 11 c.2191 C > T (p. P731S) Exon 19 0.851 This study New mutations are shown in bold. Login to comment
127 The first novel mutation detected on the ABCB4 gene is a frameshift mutation (p.I587DfsX603) and predicts the formation of Table 3 Clinical details of patients with ABCB4 mutations. Parameters Patient 1 L73V Patient 2 T175A Patient 3 N510S Patient 4 I587DfsX603 Patient 5 I738LfsX744 Onset of pruritus 3rd trimester 3rd trimester 3rd trimester 3rd trimester 2nd trimester Parity 3 2 2 2 1 Previous ICP Yes No Yes Yes Yes Peak of AST (U/L) 82 79 133 204 43 Peak of ALT (U/L) 123 156 238 382 76 Peak of Bilirubin (mg/dL) 0.14 0.81 Nd 2.8 2.07 Peak of GGT (U/L) 6 25 Nd 67 54 Total bile acids (òe;mol/L) 28.7 41 128 Nd 114.5 Delivery Caesarean section (37w+5 )a Caesarean section (36w)a Caesarean section (39w)a Caesarean section (32w)a Caesarean section (33w+4 )a Cholelithiasis No No No Yes No UDCA therapy Yes No No No Yes AST: aspartate aminotransferase; ALT: alanine aminotransferase; GGT: ॹ-glutamyl transpeptidase; Nd: not determined. a Caesarean section due to pregnancy complications related to ICP (foetal distress and/or intolerable pruritus and/or persistent elevation of AST and ALT). Login to comment
70 The p.L73V, the p.T175A and the p.N510S were previously described in literature [12,24]. Login to comment
102 Nucleotide change and effect on protein Location PSIC scores by PolyPhen-2 analysis Reference 1 c.217 C > G (p. L73V) Exon 4 0.489 [12] 2 c.523 A > G (p.T175A) Exon 6 0.774 [12] 3 c.1529 A > G (p.N510S) Exon 13 2.075 [24] 4 c.1758 1759 ins G (p.I587DfsX603) Exon 15 X This study 5 c.2211(+1) G > T (p.I738LfsX744) 5 Intron 17 X This study ABCB11 mutations 6 c.403 G > A (p.E135K) Exon 6 0.502 [26] 7 c.852 T > A (p.V284D) Exon 9 2.175 This study 8 c.1445 A > G (p.D482G) Exon 14 1.364 [26-28] 9 c.1674 G > C (p.Q558H) Exon 15 1.383 This study 10 c.2093 G > A (p.R698H) Exon 18 0.821 [12,25] 11 c.2191 C > T (p. P731S) Exon 19 0.851 This study New mutations are shown in bold. Login to comment
128 The first novel mutation detected on the ABCB4 gene is a frameshift mutation (p.I587DfsX603) and predicts the formation of Table 3 Clinical details of patients with ABCB4 mutations. Parameters Patient 1 L73V Patient 2 T175A Patient 3 N510S Patient 4 I587DfsX603 Patient 5 I738LfsX744 Onset of pruritus 3rd trimester 3rd trimester 3rd trimester 3rd trimester 2nd trimester Parity 3 2 2 2 1 Previous ICP Yes No Yes Yes Yes Peak of AST (U/L) 82 79 133 204 43 Peak of ALT (U/L) 123 156 238 382 76 Peak of Bilirubin (mg/dL) 0.14 0.81 Nd 2.8 2.07 Peak of GGT (U/L) 6 25 Nd 67 54 Total bile acids (òe;mol/L) 28.7 41 128 Nd 114.5 Delivery Caesarean section (37w+5 )a Caesarean section (36w)a Caesarean section (39w)a Caesarean section (32w)a Caesarean section (33w+4 )a Cholelithiasis No No No Yes No UDCA therapy Yes No No No Yes AST: aspartate aminotransferase; ALT: alanine aminotransferase; GGT: ॹ-glutamyl transpeptidase; Nd: not determined. a Caesarean section due to pregnancy complications related to ICP (foetal distress and/or intolerable pruritus and/or persistent elevation of AST and ALT). Login to comment

[hide] ABCB4 mutations underlie hormonal cholestasis but ... World J Gastroenterol. 2014 May 21;20(19):5867-74. doi: 10.3748/wjg.v20.i19.5867. Jirsa M, Bronsky J, Dvorakova L, Sperl J, Smajstrla V, Horak J, Nevoral J, Hrebicek M
ABCB4 mutations underlie hormonal cholestasis but not pediatric idiopathic gallstones.
World J Gastroenterol. 2014 May 21;20(19):5867-74. doi: 10.3748/wjg.v20.i19.5867., [PMID:24914347]

Abstract [show]
AIM: To investigate the contribution of ABCB4 mutations to pediatric idiopathic gallstone disease and the potential of hormonal contraceptives to prompt clinical manifestations of multidrug resistance protein 3 deficiency. METHODS: Mutational analysis of ABCB4, screening for copy number variations by multiplex ligation-dependent probe amplification, genotyping for low expression allele c.1331T>C of ABCB11 and genotyping for variation c.55G>C in ABCG8 previously associated with cholesterol gallstones in adults was performed in 35 pediatric subjects with idiopathic gallstones who fulfilled the clinical criteria for low phospholipid-associated cholelithiasis syndrome (LPAC, OMIM #600803) and in 5 young females with suspected LPAC and their families (5 probands, 15 additional family members). The probands came to medical attention for contraceptive-associated intrahepatic cholestasis. RESULTS: A possibly pathogenic variant of ABCB4 was found only in one of the 35 pediatric subjects with idiopathic cholesterol gallstones whereas 15 members of the studied 5 LPAC kindreds were confirmed and another one was highly suspected to carry predictably pathogenic mutations in ABCB4. Among these 16, however, none developed gallstones in childhood. In 5 index patients, all young females carrying at least one pathogenic mutation in one allele of ABCB4, manifestation of LPAC as intrahepatic cholestasis with elevated serum activity of gamma-glutamyltransferase was induced by hormonal contraceptives. Variants ABCB11 c.1331T>C and ABCG8 c.55G>C were not significantly overrepresented in the 35 examined patients with suspect LPAC. CONCLUSION: Clinical criteria for LPAC syndrome caused by mutations in ABCB4 cannot be applied to pediatric patients with idiopathic gallstones. Sexual immaturity even prevents manifestation of LPAC.

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26 In our previous study[10] we focused on the role of the common variants c.523A>G (p.Thr175Ala) and c.1954A>G (p.Arg652Gly) in ABCB4, c.1331T>C (p.Val444Ala) in ABCB11 and c.55 G>C (p.Asp19His) in ABCG8 in pediatric gallstone disease. Login to comment
80 Families with suspect LPAC Two of the five probands carried a single heterozygous nonsense mutation, two were heterozygotes for the missense mutation c.523A>G (p.Thr175Ala, rs58238559), and one was a compound heterozygote for the same missense mutation (c.523A>G) and for the frameshift mutation c.1371delG (p.Gln458Argfs*7) (Figure 2). Login to comment
82 While the number of patients was too low to make the result fully convincing, this observation suggests that p.Thr175Ala at least confers susceptibility to hepatobiliary disease. Login to comment
89 This indicates that the null mutations in familiesߙIߙ- III and even the missense mutation leading to p.Thr175Ala in families IV and ࡴ all are likely sufficient in a heterozygous state to promote the LPAC phenotype. Login to comment
99 Interestingly, the ABCB4 variation c.523A>G (p. Thr175Ala), found in three index patients with LPAC, Patient. Login to comment
107 The substitution p.Thr175Ala, predicted uniformly to impair protein function by SIFT, PMut, PolyPhen-2 and MutationTaster is thus considered a disease-associated mutation[3] with incomplete penetrance. Login to comment
125 His DNA sample was not available for analysis; however, he is most likely a heterozygous carrier of c.523A>G (p.Thr175Ala) as depicted. Login to comment
128 c.1331T|T c.55G|G c.1331T|T c.55G|G c.1331T|T c.55G|G c.1331C|C c.55G|G c.1331C|C c.55G|G c.1331C|C c.55G|G c.1331C|C c.55G|G c.1331T|C c.55G|G c.1331T|C c.55G|G c.1331C|C c.55G|G c.1331C|C c.55G|G c.1331C|C c.55G|G c.1331C|C c.55G|G c.1331T|C c.55G|G c.1331T|C c.55G|G c.1331T|C c.55G|G c.1331T|C c.55G|C c.1331T|C c.55C|C c.1331T|C c.55G|C c.1331T|T c.55G|C I II III IV ࡴ n.a. n.a. p.Ser1203X F1-1 F2-1 F1-1 n.a. F3-1 F3-2 F1-2 F2-1 p.Thr175Ala p.Gln458Argfs*7 LPAC phenotype p.Thr175Ala p.Thr175Ala p.Glu501X young adults[26] , together with the decreased biliary secretion rate of phosphatidylcholine in carriers of mutations in ABCB4, shifts the cholesterol-solubility equilibrium to the borderline. Login to comment
132 In contrast, two patients heterozygous for the missense MDR3 variant p.Thr175Ala tolerated long-term administration of oral contraceptives after cholecystectomy without apparent worsening in hepatobiliary disease. Login to comment
25 In our previous study[10] we focused on the role of the common variants c.523A>G (p.Thr175Ala) and c.1954A>G (p.Arg652Gly) in ABCB4, c.1331T>C (p.Val444Ala) in ABCB11 and c.55 G>C (p.Asp19His) in ABCG8 in pediatric gallstone disease. Login to comment
79 Families with suspect LPAC Two of the five probands carried a single heterozygous nonsense mutation, two were heterozygotes for the missense mutation c.523A>G (p.Thr175Ala, rs58238559), and one was a compound heterozygote for the same missense mutation (c.523A>G) and for the frameshift mutation c.1371delG (p.Gln458Argfs*7) (Figure 2). Login to comment
81 While the number of patients was too low to make the result fully convincing, this observation suggests that p.Thr175Ala at least confers susceptibility to hepatobiliary disease. Login to comment
88 This indicates that the null mutations in familiesߙIߙ- III and even the missense mutation leading to p.Thr175Ala in families IV and ࡴ all are likely sufficient in a heterozygous state to promote the LPAC phenotype. Login to comment
98 Interestingly, the ABCB4 variation c.523A>G (p. Thr175Ala), found in three index patients with LPAC, Patient. Login to comment
106 The substitution p.Thr175Ala, predicted uniformly to impair protein function by SIFT, PMut, PolyPhen-2 and MutationTaster is thus considered a disease-associated mutation[3] with incomplete penetrance. Login to comment
124 His DNA sample was not available for analysis; however, he is most likely a heterozygous carrier of c.523A>G (p.Thr175Ala) as depicted. Login to comment
127 c.1331T|T c.55G|G c.1331T|T c.55G|G c.1331T|T c.55G|G c.1331C|C c.55G|G c.1331C|C c.55G|G c.1331C|C c.55G|G c.1331C|C c.55G|G c.1331T|C c.55G|G c.1331T|C c.55G|G c.1331C|C c.55G|G c.1331C|C c.55G|G c.1331C|C c.55G|G c.1331C|C c.55G|G c.1331T|C c.55G|G c.1331T|C c.55G|G c.1331T|C c.55G|G c.1331T|C c.55G|C c.1331T|C c.55C|C c.1331T|C c.55G|C c.1331T|T c.55G|C I II III IV ࡴ n.a. n.a. p.Ser1203X F1-1 F2-1 F1-1 n.a. F3-1 F3-2 F1-2 F2-1 p.Thr175Ala p.Gln458Argfs*7 LPAC phenotype p.Thr175Ala p.Thr175Ala p.Glu501X young adults[26] , together with the decreased biliary secretion rate of phosphatidylcholine in carriers of mutations in ABCB4, shifts the cholesterol-solubility equilibrium to the borderline. Login to comment
131 In contrast, two patients heterozygous for the missense MDR3 variant p.Thr175Ala tolerated long-term administration of oral contraceptives after cholecystectomy without apparent worsening in hepatobiliary disease. Login to comment

[hide] Exome sequencing of a family with lone, autosomal ... BMC Genet. 2015 Feb 11;16:15. doi: 10.1186/s12863-015-0177-0. Maciag A, Villa F, Ferrario A, Spinelli CC, Carrizzo A, Malovini A, Torella A, Montenero C, Parisi A, Condorelli G, Vecchione C, Nigro V, Montenero AS, Puca AA
Exome sequencing of a family with lone, autosomal dominant atrial flutter identifies a rare variation in ABCB4 significantly enriched in cases.
BMC Genet. 2015 Feb 11;16:15. doi: 10.1186/s12863-015-0177-0., [PMID:25888430]

Abstract [show]
BACKGROUND: Lone atrial flutter (AFL) and atrial fibrillation (AF) are common and sometimes consequential cardiac conduction disorders with a strong heritability, as underlined by recent genome-wide association studies that identified genetic modifiers. Follow-up family-based genetic analysis also identified Mendelian transmission of disease alleles. Three affected members were exome-sequenced for the identification of potential causative mutations, which were subsequently validated by direct sequencing in the other 3 affected members. Taqman assay was then used to confirm the role of any mutation in an independent population of sporadic lone AFL/AF cases. RESULTS: The family cluster analysis provided evidence of genetic inheritance of AFL in the family via autosomal dominant transmission. The exome-sequencing of 3 family members identified 7 potential mutations: of these, rs58238559, a rare missense genetic variant in the ATP-binding cassette sub-family B, member 4 (ABCB4) gene was carried by all affected members. Further analysis of 82 subjects with sporadic lone AF, 63 subjects with sporadic lone AFL, and 673 controls revealed that the allele frequency for this variation was significantly higher in cases than in the controls (0.05 vs. 0.01; OR = 3.73; 95% CI = 1.16-11.49; P = 0.013). CONCLUSIONS: rs58238559 in ABCB4 is a rare missense variant with a significant effect on the development of AFL/AF.

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62 The rs58238559 single-nucleotide polymorphism (SNP) is located in the ABCB4 gene on chr7:87082273, and determines the nucleotide variation A599G (NM_000443.3) (Figure 2), producing the amino acid change Thr175Ala (NP_000434.1). Login to comment
65 Taken together, the above data leads to the speculation that ABCB4 variants at position 175 produce a modest genetic predisposition for gallbladder disease, whereas Thr175Ala produces a familial autosomal form of lone AFL. Login to comment
73 With respect to the rest of the cohort, individuals with the Thr175Ala amino acid change in ABCB4 have a 3.75-fold increase in the probability of developing atrial fibrillation/ flutter. Login to comment
82 The present study of a family with a strong clustering of AFL-affected members has found that the rs58238559 SNP in ABCB4, which produces a Thr175Ala amino acid change, is associated with AFL/AF. Login to comment
61 The rs58238559 single-nucleotide polymorphism (SNP) is located in the ABCB4 gene on chr7:87082273, and determines the nucleotide variation A599G (NM_000443.3) (Figure 2), producing the amino acid change Thr175Ala (NP_000434.1). Login to comment
64 Taken together, the above data leads to the speculation that ABCB4 variants at position 175 produce a modest genetic predisposition for gallbladder disease, whereas Thr175Ala produces a familial autosomal form of lone AFL. Login to comment
72 With respect to the rest of the cohort, individuals with the Thr175Ala amino acid change in ABCB4 have a 3.75-fold increase in the probability of developing atrial fibrillation/ flutter. Login to comment
81 The present study of a family with a strong clustering of AFL-affected members has found that the rs58238559 SNP in ABCB4, which produces a Thr175Ala amino acid change, is associated with AFL/AF. Login to comment

[hide] ABCB4 mutations in adult patients with cholestatic... J Gastroenterol. 2015 Sep 1. Degiorgio D, Crosignani A, Colombo C, Bordo D, Zuin M, Vassallo E, Syren ML, Coviello DA, Battezzati PM
ABCB4 mutations in adult patients with cholestatic liver disease: impact and phenotypic expression.
J Gastroenterol. 2015 Sep 1., [PMID:26324191]

Abstract [show]
BACKGROUND: The ABCB4 gene encodes the MDR3 protein. Mutations of this gene cause progressive familial intrahepatic cholestasis type 3 (PFIC3) in children, but their clinical relevance in adults remains ill defined. The study of a well-characterized adult patient series may contribute to refining the genetic data regarding cholangiopathies of unknown origin. Our aim was to evaluate the impact of ABCB4 mutations on clinical expression of cholestasis in adult patients. METHODS: We consecutively evaluated 2602 subjects with hepatobiliary disease. Biochemical evidence of a chronic cholestatic profile (CCP) with elevated serum gamma-glutamyltransferase activity or diagnosis of intrahepatic cholestasis of pregnancy (ICP) and juvenile cholelithiasis (JC) were inclusion criteria. The personal/family history of additional cholestatic liver disease (PFH-CLD), which includes ICP, JC, or hormone-induced cholestasis, was investigated. Mutation screening of ABCB4 was carried out in 90 patients with idiopathic chronic cholestasis (ICC), primary biliary cirrhosis (PBC), primary sclerosing cholangitis (PSC), ICP, and JC. RESULTS: Eighty patients had CCP. PSC and ICC patients with PFH-CLD had earlier onset of disease than those without it (p = 0.003 and p = 0.023, respectively). The mutation frequency ranged from 50 % (ICP, JC) to 17.6 % (PBC). Among CCP patients, presence or absence of PFH-CLD was associated with ABCB4 mutations in 26.8 vs 5.1 % (p = 0.013), respectively; in the subset of ICC and PSC patients, the corresponding figures were 44.4 vs 0 % (p = 0.012) and 28.6 vs 8.7 % (p = 0.173). CONCLUSIONS: Cholangiopathies attributable to highly penetrant ABCB4 mutant alleles are identifiable in a substantial proportion of adults that generally have PFH-CLD. In PSC and ICC phenotypes, patients with MDR3 deficiency have early onset of disease.

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72 CCP chronic cholestatic profile, NCCP patients without chronic cholestatic profile, PBC primary biliary cirrhosis, PSC primary sclerosing cholangitis, ICP intrahepatic cholestasis of pregnancy, JC juvenile cholelithiasis, AIH autoimmune hepatitis, OS overlap syndrome between AIH and PBC or PSC, ICC idiopathic chronic cholestasis; a with (n = 14) or without (n = 23) other cholangiopathies in the personal/family history (see ''Methods``), b with (n = 9) or without (n = 15) other cholangiopathies in the personal/family history (see ''Methods``), c with (n = 2) or without (n = 2) other cholangiopathies in the personal/family history (see ''Methods``) Table 1 Heterozygous nucleotide changes within the ABCB4 gene identified in 18 adult patients with cholangiopathies and predicted impact on MDR3 Nucleotide changea Involved regions Type of mutation Mutant protein Location on the protein Degree of conservationb Reference genotypesc c.217C[G Exon 4 Missense p.(L73V) TM1 B 7, 21 c.475C[T Exon 6 Non-sense p.(R159X) ICD1 X 8, 14 c.523A[G Exon 6 Missense p.(T175A) ICD1 B 18, 21, 8, 25, 14 c.959C[T Exon 9 Missense p.(S320F) TM5 B 18, 8, 14 c.1529A[G Exon 13 Missense p.(N510S) N-ter NBD B 14 c.1531G[A Exon 13 Missense p.(A511T) N-ter NBD A 8, 14 c.1633C[T Exon 14 Missense p.(R545C) N-ter NBD A 21 c.1769G[A Exon 15 Missense p.(R590Q) N-ter NBD A 8, 13, 14, 25 c.1846G[A Exon 15 Missense p.(E616K) N-ter NBD A This study (JN392435) c.1901G[A Exon 16 Missense p.G634E Linker region B This study (JN392436) c.2431G[C Exon 20 Missense p.(G811R) ICD4 A This study (JN392437) c.2544_2548delATCAT Exon 21 Frameshift p.(S849YfsX24) TM9 X This study (JN392438) c.2576T[G Exon 21 Missense p.(L859W) TM10 B This study (JN392439) c.2844G[C Exon 23 Missense p.(M948I) TM11 B This study (JN392440) c.3541C[T Exon 27 Non-sense p.(Q1181X) C-ter NBD X This study (JN392441) TM transmembrane domain, ICD intracellular domain, N-ter NBD N-terminal nucleotide binding domain, C-ter NBD C-terminal nucleotide binding domain a The mutations were numbered according to GenBank NM_018849 and NP_061337. Login to comment
76 A second group of seven mutations is ascribed to type B [p.(L73V), p.(T175A), p.(N510S), p.(G634E), p.(L859W), and p.(M948I); and p.(S320F)] (Figs. 2, 3, residues in blue). Login to comment
81 L73V T175A S320F N510S A511T R590Q E616K R545C G634E G811R L859W M948I ...69_SGLPLMMIV_77... ...69_SGLPLMMIV_77... ...66_SGLPLMMIV_74... ...66_SGLPLMMIV_74... ...69_SGLPLMMIV_77... ...69_SGLPLMMIV_77... ...67_SGLPLMMIV_75..... ...63_AGLPLMMLV_71... ...92_LGFPIMTIL_100.. ...59_MSEPLMTVV_67... ...77_GFAMPALTI_85... ...79_ASFPIMSIL_87... ..107_LGMPLMSLV_115.. ...89_AGLPLMSIL_97... ...39_ASDTFMLSL_47... ...39_ASDTFMLSL_47... ...39_AADTYMISL_47... ...28_GIPMLIPLL_36... 171_TELNTRLTD_179... 171_TELNTRLTD_179... 168_TELNTRLTD_176... 168_TELNTRLTD_176... 171_TELNTRLTD_179... 171_TELNTRLTD_179... 169_TELNTRLTD_177... 169_GELNTRLTD_177... 180_GEVVGRMSG_188... 146_GEAASRISA_154.. 164_GEVVGRMSG_172.. 167_GEVVGRMSG_175.. 197_GEITTRITT_205.. 193_GTLATKLFD_201.. 122_GTLLSRITY_130... 122_GTLLSRITY_130... 122_GGLLSRITY_130... 118_GQVISRVIN_126... 586_VIAHRLSTV_594... 586_VIAHRLSTV_594... 583_VIAHRLSTI_591... 583_VIAHRLSTV_591... 586_VIAHRLSTI_594... 586_VIAHRLSTI_594... 584_VIAHRLSTI_592... 584_VIAHRLSTV_592... 595_VVAHRLSTV_603... 561_IVAHRLSTI_569... 579_VIAHRLTTI_587... 582_IVAHRLSTV_590... 621_VIAHRLSTI_629... 608_IIAHRLSTI_616... 534_VIAHRLSTI_542... 534_VIAHRLSTI_542... 534_VIAHRLSTI_542... 531_IVAHRLSTI_539... 316_FWYGSTLVI_324... 316_FWYGSTLVI_324... 313_FWYGSTLVI_321... 313_FWYGSTLVI_321... 316_FWYGSTLVI_324... 316_FWYGSTLVI_324... 314_FWYGSTLVI_322... 314_FWYGTTLVL_322... 325_VWYGGKMIL_333... 291_FWYGAKLVI_299... 309_LWYGSKLVL_317... 312_IWFGGKMIL_320... 342_FWEGGRLLH_350... 338_FYIGVGWVH_346... 267_LYAASFPSV_275... 267_LYAASFPSV_275... 267_LFLASVDSI_275... 263 IGVGAYLAI 271... 506_VKEANAYEFI_515... 506_VKEANAYEFI_515... 503_VKEANAYDFI_512... 503_VKEANAYDFI_512... 506_VKEANAYEFI_515... 504_VKEANAYEFI_513... 504_VKDANAYEFI_513... 504_VKEANAYDFI_513... 515_TELANASKFI_524... 481_AELANAANFI_490... 499_AYLANAARFI_508... 502_TELANAAKFI_511... 541_AKLANAYDFI_550... 528_CKMANAEKFI_537... 454_ARMAYAMDFI_463... 454_ARMAYAMDFI_463... 454_ARQAHAMEFI_463... 451_AKMANAHDFI_460... 541_IAIARALVR_549... 541_IAIARALVR_549... 538_IAIARALVR_546... 538_IAIARALVR_546... 541_IAIARALVR_549... 541_IAIARALVR_549... 539_IAIARALVR_547... 539_IAIARALVR_547... 550_IAVARAILK_558... 516_IAIARAILK_524... 534_VAIARAILK_542... 537_IAIARAILK_545... 576_IAIARAVIS_584... 563_IAIARALVR_571... 489_IAIARALLR_497... 489_IAIARALLR_497... 489_VAIARALLR_497... 486_LSIARIFLN_494... ...612_GSHSELMKK_620... ...612_GSHSELMKK_620... ...609_GSHSELMKK_617... ...609_GSHSELIKK_617... ...612_GSHGELMKK_620... ...612_GNHRELMKK_620... ...610_GSHNELMKK_618... ...610_GNHDELMKE_618... ...621_GSHSELLRD_629... ...587_GSHDELIKD_595... ...605_GTHFDLVQR_613... ...608_GSHSELLKD_616... ...647_GSHNELLDL_655... ...634_GDHRALMAQ_642... ...560_GTHNDLLEH_568... ...560_GTHSELLAQ_568... ...560_GRHADLLAQ_568... ...557_GTHRELIAK_565... 630_MQTSGSQIQ_638... 630_MQTSGSQIQ_638... 627_MQTAGSQIL_635... 627_MQTSGSQIL_635... 630_TQISGSQIQ_638... 630_MQTSGNQTQ_638... 628_MQTSGNQIQ_636... 628_MQTAGNEVE_636... 640_LQEDTKQTE_648... 620_SEVSTSRLK_628... 624_LQEMHQPPP_632... 627_LQEVNKESK_635... 666_QKLSGGEKD_674... 652_AQTFTDAVD_660... 578_MQFGQ----_582... 578_MQFGQ----_582... 578_IQFGE----_582... 575_IQNL-----_578... 807_KNSTGALST_815... 807_KNSTGALST_815... 804_KNSTGALST_812... 806_KNSTGALST_814... 804_KNSTGALST_812... 809_KNSTGALST_817... 806_KNSTGALST_814... 808_KNTTGALTT_816... 825_ENSSGAIGA_833... 797_SHSSGSLGA_805... 835_ENSSGALGA_843... 822_EHSSGAIGA_830... 891_ENTVGAITT_899... 849_QNASGKIST_857... 118_KQSTGTLLS_126... 118_KQSTGTLLS_126... 118_QESTGGLLS_126... 114_NNQVGQVIS_122... 855_QLTLLLLAV_863.... 855_QLTLLLLAV_863.... 852_QLTLLLLSV_860.... 854_QLTLLLLSV_862.... 852_QLTLLLLSV_860.... 857_QLTLLLLVV_865.... 854_QLTLLLLSV_862.... 856_QLTLLLLAI_864.... 873_QLAFIVLAM_881.... 845_KLTLTIMCP_853.... 883_QLALLVLAL_891.... 870_QLALVILVL_878.... 939_KLGLVTLST_947... 897_QMALLIIAI_905.... 166_QLSIILIVL_174.... 166_QLSIILVVL_174.... 166_QLSLVLIVV_174.... 162_KLTLAALFI_170.... 944_SQAFMYFSY_952... 944_SQAFMYFSY_952... 941_SQAFMYFSY_949... 943_SQAFMYFSY_951... 941_SQAFMYFSY_949... 946_SQAFMYFSY_954... 943_SQAFMYFSY_951... 945_TQAMMYFSY_953... 962_SFFVLFSSY_970... 940_SYLMVYLTY_948... 972_SNFVLFGSY_980... 959_SFFLLFSVY_967... 1028_AQGVTFLIN_1036.. 986_ASSVLYLLN_994... 255_IQLIASLAL_263... 255_IQLIASLAL_263... 255_IQMIASLAL_263... 251_INTVTDIGP_259... Hs_MDR3 Pt_MDR3 Mm_MDR3 Rn_MDR3 Bt_MDR3 Cf_MDR3 Md_MDR3 Hs_MDR1 At_MDR Os_MDR Sm_MDR Ptr_MDR Sp_MDR Ce_P-gly Esch-coli_Msba Salm-typh_Msba Vibrio-ch_Msba Staph-au_Sav1866 Hs_MDR3 Pt_MDR3 Mm_MDR3 Rn_MDR3 Bt_MDR3 Cf_MDR3 Md_MDR3 Hs_MDR1 At_MDR Os_MDR Sm_MDR Ptr_MDR Sp_MDR Ce_P-gly Esch-coli_Msba Salm-typh_Msba Vibrio-ch_Msba Staph-au_Sav1866 Fig. 2 Multiple sequence alignment of 18 ABC proteins concerning the amino acid sequences around the 12 ABCB4 missense mutations identified in this study. Login to comment
99 When the 19 patients affected by PBC, AIH, or OS, in whom PFH-CLD was among the enrollment criteria, were excluded from the analysis, the S320F L859W L73V M948I N-ter T175A G811R R545C A511T N510S R590Q E616K G634E C-ter Fig. 3 Ribbon representation of the three-dimensional structure of human MDR3. Login to comment
141 p.(S320F) Yes JC/HIC 16 F PSC 55 p.(R590Q) Yes 7 M ICC 16 p.(R545C) Yes JC Father of patient 72 18a,b M ICC 34 p.(S849YfsX24) Yes JC Family history of JC 49 F ICC 32 p.(G811R) Yes ICP/JC Family history of JC 72 F ICC 12 p.(R545C) Yes ICP/JC Daughter of patient 72 68 F PBC 31 p.(T175A) No ICP 73a F PBC 58 p.(R590Q) Yes JC 75 F PBC 64 p.(L73V) No JC 38 M JC 18 p.(S320F) No 55 M JC 26 p.(Q1181X) Yes 81 F JC 39 p.(R590Q) ? Login to comment