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Abstract
Bile acid transport is a complex physiologic process, of which disruption at any step can lead to progressive intrahepatic cholestasis (PFIC). The first described PFIC disorders were originally named as such before identification of a genetic cause. However, advances in clinical molecular genetics have led to the identification of additional disorders that can cause these monogenic inherited cholestasis syndromes, and they are now increasingly referred to by the affected protein causing disease. The list of PFIC disorders is expected to grow as more causative genes are discovered. Here forth, we present a comprehensive overview of known PFIC disorders.
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Affiliation(s)
- Sara Hassan
- Department of Pediatrics, Division of Gastroenterology, Hepatology and Nutrition, Mayo Clinic, 200 First Street Southwest, Rochester, MN 55905, USA. https://twitter.com/SaraHassanMD
| | - Paula Hertel
- Department of Pediatrics, Division of Gastroenterology, Hepatology and Nutrition, Baylor College of Medicine, Texas Children's Hospital, 6621 Fannin Street, Houston, TX 77030, USA.
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2
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Targeted-Capture Next-Generation Sequencing in Diagnosis Approach of Pediatric Cholestasis. Diagnostics (Basel) 2022; 12:diagnostics12051169. [PMID: 35626323 PMCID: PMC9140938 DOI: 10.3390/diagnostics12051169] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 04/15/2022] [Accepted: 04/29/2022] [Indexed: 02/05/2023] Open
Abstract
Background: Cholestasis is a frequent and severe condition during childhood. Genetic cholestatic diseases represent up to 25% of pediatric cholestasis. Molecular analysis by targeted-capture next generation sequencing (NGS) has recently emerged as an efficient diagnostic tool. The objective of this study is to evaluate the use of NGS in children with cholestasis. Methods: Children presenting cholestasis were included between 2015 and 2020. Molecular sequencing was performed by targeted capture of a panel of 34 genes involved in cholestasis and jaundice. Patients were classified into three categories: certain diagnosis; suggested diagnosis (when genotype was consistent with phenotype for conditions without any available OMIM or ORPHANET-number); uncertain diagnosis (when clinical and para-clinical findings were not consistent enough with molecular findings). Results: A certain diagnosis was established in 169 patients among the 602 included (28.1%). Molecular studies led to a suggested diagnosis in 40 patients (6.6%) and to an uncertain diagnosis in 21 patients (3.5%). In 372 children (61.7%), no molecular defect was identified. Conclusions: NGS is a useful diagnostic tool in pediatric cholestasis, providing a certain diagnosis in 28.1% of the patients included in this study. In the remaining patients, especially those with variants of uncertain significance, the imputability of the variants requires further investigations.
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3
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Abstract
Cholestatic jaundice is a common presenting feature of hepatobiliary and/or metabolic dysfunction in the newborn and young infant. Timely detection of cholestasis, followed by rapid step-wise evaluation to determine the etiology, is crucial to identify those causes that are amenable to medical or surgical intervention and to optimize outcomes for all infants. In the past 2 decades, genetic etiologies have been elucidated for many cholestatic diseases, and next-generation sequencing, whole-exome sequencing, and whole-genome sequencing now allow for relatively rapid and cost-effective diagnosis of conditions not previously identifiable via standard blood tests and/or liver biopsy. Advances have also been made in our understanding of risk factors for parenteral nutrition-associated cholestasis/liver disease. New lipid emulsion formulations, coupled with preventive measures to decrease central line-associated bloodstream infections, have resulted in lower rates of cholestasis and liver disease in infants and children receiving long-term parental nutrition. Unfortunately, little progress has been made in determining the exact cause of biliary atresia. The median age at the time of the hepatoportoenterostomy procedure is still greater than 60 days; consequently, biliary atresia remains the primary indication for pediatric liver transplantation. Several emerging therapies may reduce the bile acid load to the liver and improve outcomes in some neonatal cholestatic disorders. The goal of this article is to review the etiologies, diagnostic algorithms, and current and future management strategies for infants with cholestasis.
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Affiliation(s)
- Amy G Feldman
- Digestive Health Institute, Children's Hospital Colorado, Section of Pediatric Gastroenterology, Hepatology and Nutrition, University of Colorado School of Medicine, Aurora, CO
| | - Ronald J Sokol
- Digestive Health Institute, Children's Hospital Colorado, Section of Pediatric Gastroenterology, Hepatology and Nutrition, University of Colorado School of Medicine, Aurora, CO
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4
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Jeyaraj R, Bounford KM, Ruth N, Lloyd C, MacDonald F, Hendriksz CJ, Baumann U, Gissen P, Kelly D. The Genetics of Inherited Cholestatic Disorders in Neonates and Infants: Evolving Challenges. Genes (Basel) 2021; 12:1837. [PMID: 34828443 PMCID: PMC8621872 DOI: 10.3390/genes12111837] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 11/15/2021] [Accepted: 11/16/2021] [Indexed: 12/26/2022] Open
Abstract
Many inherited conditions cause cholestasis in the neonate or infant. Next-generation sequencing methods can facilitate a prompt diagnosis in some of these cases; application of these methods in patients with liver diseases of unknown cause has also uncovered novel gene-disease associations and improved our understanding of physiological bile secretion and flow. By helping to define the molecular basis of certain cholestatic disorders, these methods have also identified new targets for therapy as well patient subgroups more likely to benefit from specific therapies. At the same time, sequencing methods have presented new diagnostic challenges, such as the interpretation of single heterozygous genetic variants. This article discusses those challenges in the context of neonatal and infantile cholestasis, focusing on difficulties in predicting variant pathogenicity, the possibility of other causal variants not identified by the genetic screen used, and phenotypic variability among patients with variants in the same genes. A prospective, observational study performed between 2010-2013, which sequenced six important genes (ATP8B1, ABCB11, ABCB4, NPC1, NPC2 and SLC25A13) in an international cohort of 222 patients with infantile liver disease, is given as an example of potential benefits and challenges that clinicians could face having received a complex genetic result. Further studies including large cohorts of patients with paediatric liver disease are needed to clarify the spectrum of phenotypes associated with, as well as appropriate clinical response to, single heterozygous variants in cholestasis-associated genes.
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Affiliation(s)
- Rebecca Jeyaraj
- National Institute for Health Research Great Ormond Street Hospital Biomedical Research Centre, University College London, London WC1N 1EH, UK;
| | - Kirsten McKay Bounford
- West of Scotland Centre for Genomic Medicine, Queen Elizabeth University Hospital, Glasgow G51 4TF, UK;
| | - Nicola Ruth
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham B15 2TT, UK; (N.R.); (U.B.); (D.K.)
- Liver Unit, Birmingham Women’s and Children’s Hospital, Birmingham B4 6NH, UK;
| | - Carla Lloyd
- Liver Unit, Birmingham Women’s and Children’s Hospital, Birmingham B4 6NH, UK;
| | - Fiona MacDonald
- West Midlands Regional Genetics Service, Birmingham Women’s and Children’s Hospital, Birmingham B15 2TG, UK;
| | - Christian J. Hendriksz
- Steve Biko Academic Unit, Level D3 New Pretoria Academic Hospital, Malherbe Street, Pretoria 0002, South Africa;
| | - Ulrich Baumann
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham B15 2TT, UK; (N.R.); (U.B.); (D.K.)
- Paediatric Gastroenterology and Hepatology, Hannover Medical School, 30625 Hannover, Germany
| | - Paul Gissen
- National Institute for Health Research Great Ormond Street Hospital Biomedical Research Centre, University College London, London WC1N 1EH, UK
| | - Deirdre Kelly
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham B15 2TT, UK; (N.R.); (U.B.); (D.K.)
- Liver Unit, Birmingham Women’s and Children’s Hospital, Birmingham B4 6NH, UK;
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5
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Li LT, Li ZD, Yang Y, Lu Y, Xie XB, Chen L, Feng JY, Knisely AS, Wang JS. ABCB11 deficiency presenting as transient neonatal cholestasis: Correlation with genotypes and BSEP expression. Liver Int 2020; 40:2788-2796. [PMID: 32808743 DOI: 10.1111/liv.14642] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Revised: 08/10/2020] [Accepted: 08/13/2020] [Indexed: 12/12/2022]
Abstract
BACKGROUND & AIMS ABCB11 deficiency presenting in infancy is believed generally to manifest as persistent/progressive cholestasis. We describe a group of patients with biallelic ABCB11 variants whose disorder manifested as transient neonatal cholestasis (TNC). METHODS Neonatal intrahepatic cholestasis in 68 children (31 males) with biallelic predictedly pathogenic variants (PPV) in ABCB11 was classified as transient (TNC group, n = 23, 11 males), intermittent (benign recurrent intrahepatic cholestasis [BRIC] group, n = 3, 1 male) or persistent/ progressive (progressive familial intrahepatic cholestasis [PFIC] group, n = 42, 19 males). Clinical, genetic and bile salt export pump (BSEP) expression information was correlated with outcomes. RESULTS The median onset age of jaundice was 3 days (birth to 2 months) for the TNC group and 10.5 days (birth to 3 months) for the PFIC group (P = .034). The median length of follow-up of TNC patients was 44 months (12 months-168 months). At presentation, hepatobiliary-injury biomarker values were similar between the groups (P > .05). TNC patients (17/23) more often than PFIC patients (20/42, P = .041) harboured biallelic non-null variants (predicted not to terminate translation prematurely). TNC patient livers (7/7) more often than PFIC patient livers (5/16, P = .005) expressed immunohistochemically detectable BSEP. Kaplan-Meier analysis showed better prognosis for patients with BSEP expression (P = .009). Too few BRIC patients were available for statistical study. CONCLUSIONS Neonatal cholestasis associated with biallelic PPV in ABCB11 can resolve temporarily or persistently in one third of cases. Resolution is more likely in patients with biallelic non-null PPV or with liver BSEP expression.
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Affiliation(s)
- Li-Ting Li
- The Center for Pediatric Liver Diseases, Children's Hospital of Fudan University, Shanghai, China
| | - Zhong-Die Li
- The Center for Pediatric Liver Diseases, Children's Hospital of Fudan University, Shanghai, China
| | - Ye Yang
- Department of Pediatrics, Jinshan Hospital, Fudan University, Shanghai, China
| | - Yi Lu
- The Center for Pediatric Liver Diseases, Children's Hospital of Fudan University, Shanghai, China
| | - Xin-Bao Xie
- The Center for Pediatric Liver Diseases, Children's Hospital of Fudan University, Shanghai, China
| | - Lian Chen
- Department of Pathology, Children's Hospital of Fudan University, Shanghai, China
| | - Jia-Yan Feng
- Department of Pathology, Children's Hospital of Fudan University, Shanghai, China
| | - A S Knisely
- Institut für Pathologie, Medizinische Universität Graz, Graz, Austria
| | - Jian-She Wang
- The Center for Pediatric Liver Diseases, Children's Hospital of Fudan University, Shanghai, China.,Shanghai Key Laboratory of Birth Defects, Shanghai, China
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6
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Abstract
Neonatal cholestasis is characterized by conjugated hyperbilirubinemia in the newborn and young infant and is a sign common to over 100 hepatobiliary and/or metabolic disorders. A timely evaluation for its etiology is critical in order to quickly identify treatable causes such as biliary atresia, many of which benefit from early therapy. An expanding group of molecularly defined disorders involving bile formation, canalicular transporters, tight junction proteins and inborn errors of metabolism are being continuously discovered because of advances in genetic testing and bioinformatics. The advent of next generation sequencing has transformed our ability to test for multiple genes and whole exome or whole genome sequencing within days to weeks, enabling rapid and affordable molecular diagnosis for disorders that cannot be directly diagnosed from standard blood tests or liver biopsy. Thus, our diagnostic algorithms for neonatal cholestasis are undergoing transformation, moving genetic sequencing to earlier in the evaluation pathway once biliary atresia, "red flag" disorders and treatable disorders are excluded. Current therapies focus on promoting bile flow, reducing pruritus, ensuring optimal nutrition, and monitoring for complications, without addressing the underlying cause of cholestasis in most instances. Our improved understanding of bile formation and the enterohepatic circulation of bile acids has led to emerging therapies for cholestasis which require appropriate pediatric clinical trials. Despite these advances, the cause and optimal therapy for biliary atresia remain elusive. The goals of this review are to outline the etiologies, diagnostic pathways and current and emerging management strategies for neonatal cholestasis.
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Affiliation(s)
- Amy G. Feldman
- Pediatric Liver Center, Digestive Health Institute, Children’s Hospital Colorado, Section of Pediatric Gastroenterology, Hepatology and Nutrition, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Ronald J. Sokol
- Pediatric Liver Center, Digestive Health Institute, Children’s Hospital Colorado, Section of Pediatric Gastroenterology, Hepatology and Nutrition, University of Colorado School of Medicine, Aurora, Colorado, USA,Colorado Clinical and Translational Sciences Institute, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA,Corresponding Author: Ronald J. Sokol, Digestive Health Institute, Children’s Hospital Colorado, Box B290, 13123 E. 16th Ave., Aurora, Colorado, 80045, USA Phone: 720-777-6669, Fax: 720-777-7277,
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7
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Baghdasaryan A, Ofner-Ziegenfuß L, Lackner C, Fickert P, Resch B, Morris NM, Deutschmann A. Histological demonstration of BSEP/ABCB11 inhibition in transient neonatal cholestasis: a case report. BMC Pediatr 2020; 20:340. [PMID: 32646411 PMCID: PMC7346433 DOI: 10.1186/s12887-020-02201-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 06/12/2020] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND Idiopathic or transient neonatal cholestasis (TNC) represents a group of cholestatic disorders with unidentified origin and remains a diagnosis of exclusion. Dysfunction of hepatobiliary transporters mediating excretion of biliary constituents from hepatocytes may play a central role in the pathogenesis of cholestasis. Despite variants of bile salt (BS) export pump (BSEP/ABCB11) have already been described in TNC, the pathogenic role of BSEP dysfunction in TNC remained so far elusive. CASE PRESENTATION We report on a newly-identified heterozygous ABCB11 missense variant (c.1345G > A, p.Glu449Lys) which was associated with prolonged cholestasis in a term infant after a complicated neonatal period. Moreover, we show for the first time almost completely abolished BSEP expression on the hepatocellular membrane in TNC. CONCLUSION This report demonstrates for the first time a close association between the prolonged cholestasis in infancy and impaired BSEP expression on the hepatocyte canalicular membrane in a heterozygous carrier of newly-identified ABCB11 variant.
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Affiliation(s)
- Anna Baghdasaryan
- Division of General Pediatrics, Department of Pediatrics and Adolescent Medicine, Medical University of Graz, Auenbruggerplatz 34/2, 8036, Graz, Austria.
| | | | - Carolin Lackner
- Institute of Pathology, Medical University of Graz, Graz, Austria
| | - Peter Fickert
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Medical University of Graz, Graz, Austria
| | - Bernhard Resch
- Division of Neonatology, Department of Pediatrics and Adolescent Medicine, Medical University of Graz, Graz, Austria
| | - Nicholas Mark Morris
- Division of Neonatology, Department of Pediatrics and Adolescent Medicine, Medical University of Graz, Graz, Austria
| | - Andrea Deutschmann
- Division of General Pediatrics, Department of Pediatrics and Adolescent Medicine, Medical University of Graz, Auenbruggerplatz 34/2, 8036, Graz, Austria
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8
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Ietswaart R, Arat S, Chen AX, Farahmand S, Kim B, DuMouchel W, Armstrong D, Fekete A, Sutherland JJ, Urban L. Machine learning guided association of adverse drug reactions with in vitro target-based pharmacology. EBioMedicine 2020; 57:102837. [PMID: 32565027 PMCID: PMC7379147 DOI: 10.1016/j.ebiom.2020.102837] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 05/08/2020] [Accepted: 05/28/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Adverse drug reactions (ADRs) are one of the leading causes of morbidity and mortality in health care. Understanding which drug targets are linked to ADRs can lead to the development of safer medicines. METHODS Here, we analyse in vitro secondary pharmacology of common (off) targets for 2134 marketed drugs. To associate these drugs with human ADRs, we utilized FDA Adverse Event Reports and developed random forest models that predict ADR occurrences from in vitro pharmacological profiles. FINDINGS By evaluating Gini importance scores of model features, we identify 221 target-ADR associations, which co-occur in PubMed abstracts to a greater extent than expected by chance. Amongst these are established relations, such as the association of in vitro hERG binding with cardiac arrhythmias, which further validate our machine learning approach. Evidence on bile acid metabolism supports our identification of associations between the Bile Salt Export Pump and renal, thyroid, lipid metabolism, respiratory tract and central nervous system disorders. Unexpectedly, our model suggests PDE3 is associated with 40 ADRs. INTERPRETATION These associations provide a comprehensive resource to support drug development and human biology studies. FUNDING This study was not supported by any formal funding bodies.
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Affiliation(s)
- Robert Ietswaart
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, United States.
| | - Seda Arat
- The Jackson Laboratory, Farmington, CT 06032, United States.
| | - Amanda X Chen
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02142, United States; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
| | - Saman Farahmand
- Computational Sciences PhD program, University of Massachusetts Boston, Boston, MA 02125, United States
| | - Bumjun Kim
- Department of Chemical Engineering, Northeastern University, Boston, MA 02115, United States
| | | | - Duncan Armstrong
- Novartis Institutes for Biomedical Research, Cambridge, MA 02139, United States
| | - Alexander Fekete
- Novartis Institutes for Biomedical Research, Cambridge, MA 02139, United States
| | - Jeffrey J Sutherland
- Novartis Institutes for Biomedical Research, Cambridge, MA 02139, United States.
| | - Laszlo Urban
- Novartis Institutes for Biomedical Research, Cambridge, MA 02139, United States.
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9
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Molecular findings in children with inherited intrahepatic cholestasis. Pediatr Res 2020; 87:112-117. [PMID: 31450232 DOI: 10.1038/s41390-019-0548-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 08/01/2019] [Accepted: 08/16/2019] [Indexed: 02/07/2023]
Abstract
BACKGROUND Genetic defects account for a substantial proportion of pediatric cholestasis. This study explored the molecular findings in a large cohort of Chinese patients with inherited cholestasis. METHODS Between January 2012 and June 2016, 809 Chinese pediatric patients with suspected inherited intrahepatic cholestasis were evaluated by Sanger sequencing and/or panel sequencing. RESULTS Of the 809 patients, 273 (33.7%) obtained a genetic diagnosis. The rate of positive genetic diagnosis in patients with disease onset at 0-3 month of age was higher than that in patients with disease onset at 4 month of age or later. There were 17 distinct genetic defects diagnosed. The top 4 resulted from mutations in SLC25A13 (44.3%), JAG1 (24.5%), ABCB11 (11.0%), and ATP8B1 (5.9%). All 17 genetic disorders were diagnosed in patients with disease onset at 0-3 months of age; but only 5 were diagnosed in patients with disease onset beyond 4 months of age. A total of 217 distinct pathogenic variants, including 41 novel variants, were identified. Ten recurrent mutations were detected in SLC25A13, ATP8B1, and CYP27A1. They accounted for 48.2% of the total 477 mutant alleles. CONCLUSIONS There were 17 distinct genetic disorders diagnosed in Chinese pediatric patients with inherited cholestasis.
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10
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Feldman AG, Sokol RJ. Neonatal cholestasis: emerging molecular diagnostics and potential novel therapeutics. Nat Rev Gastroenterol Hepatol 2019; 16:346-360. [PMID: 30903105 DOI: 10.1038/s41575-019-0132-z] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Neonatal cholestasis is a group of rare disorders of impaired bile flow characterized by conjugated hyperbilirubinaemia in the newborn and young infant. Neonatal cholestasis is never physiological but rather is a sign of hepatobiliary and/or metabolic disorders, some of which might be fatal if not identified and treated rapidly. A step-wise timely evaluation is essential to quickly identify those causes amenable to treatment and to offer accurate prognosis. The aetiology of neonatal cholestasis now includes an expanding group of molecularly defined entities with overlapping clinical presentations. In the past two decades, our understanding of the molecular basis of many of these cholestatic diseases has improved markedly. Simultaneous next-generation sequencing for multiple genes and whole-exome or whole-genome sequencing now enable rapid and affordable molecular diagnosis for many of these disorders that cannot be directly diagnosed from standard blood tests or liver biopsy. Unfortunately, despite these advances, the aetiology and optimal therapeutic approach of the most common of these disorders, biliary atresia, remain unclear. The goals of this Review are to discuss the aetiologies, algorithms for evaluation and current and emerging therapeutic options for neonatal cholestasis.
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Affiliation(s)
- Amy G Feldman
- Pediatric Liver Center, Digestive Health Institute, Children's Hospital Colorado, Section of Pediatric Gastroenterology, Hepatology and Nutrition, University of Colorado School of Medicine, Aurora, CO, USA
| | - Ronald J Sokol
- Pediatric Liver Center, Digestive Health Institute, Children's Hospital Colorado, Section of Pediatric Gastroenterology, Hepatology and Nutrition, University of Colorado School of Medicine, Aurora, CO, USA. .,Colorado Clinical and Translational Sciences Institute, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
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11
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Reduced Hepatocellular Expression of Canalicular Transport Proteins in Infants with Neonatal Cholestasis and Congenital Hypopituitarism. J Pediatr 2018; 200:181-187. [PMID: 29935878 DOI: 10.1016/j.jpeds.2018.05.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2017] [Revised: 04/12/2018] [Accepted: 05/05/2018] [Indexed: 01/30/2023]
Abstract
OBJECTIVE To assess whether prolonged neonatal cholestasis, described in congenital hypopituitarism and septo-optic dysplasia (SOD), is associated with altered expression of selected canalicular ectoenzymes and canalicular transport proteins. STUDY DESIGN Children with congenital hypopituitarism (n = 21), SOD (n = 18), and cholestasis seen in our center over 26 years were reviewed. Histopathologic findings in archival liver biopsy specimens were assessed (n = 10) and in those with low/normal levels of serum γ-glutamyltransferase (GGT) activity despite conjugated hyperbilirubinemia, expression of canalicular ectoenzymes and canalicular transport proteins was evaluated immunohistochemically. RESULTS Patients presented at a median age of 8 weeks (range 3-20 weeks) with median total bilirubin 116 µmol/L (45-287 µmol/L), GGT 95 IU/L (25-707 UI/L), and serum cortisol 51 nmol/L (17-240 nmol/L). All but 3 had low free thyroxin (median 9.6 pmol/L [6.8-26.9]) with increased thyroid-stimulating hormone levels (median 5.95 mU/L [<0.1-9.24]). Liver histologic features included moderate-to-severe intralobular cholestasis with nonspecific hepatitis, giant-cell transformation of hepatocytes, and fibrosis. In all, immunohistochemical staining for canalicular ectoenzymes and canalicular transport proteins revealed a degree of reduced expression, associated with normal serum GGT values in 6 of the 10 patients, and another 6 nonbiopsied infants with cholestasis also had low/normal serum GGT activity. Sequencing of ABCB11 and ATP8B1 performed in 6 of the biopsied patients did not identify pathogenic mutations. Following replacement therapy, biochemical evidence of hepatobiliary injury resolved in all children within a median period of 6 months. CONCLUSION Hepatobiliary involvement in congenital hypopituitarism associated with SOD has a good prognosis, but its etiology remains uncertain. Immunohistochemical expression of canalicular transport proteins was reduced in available liver samples.
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12
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Wang NL, Qiu YL, Guan WC, Li G, Lu Y, Zhang MH, Luan WS, Wang JS. Splicing analysis of rare/novel synonymous or intronic variants identified in ABCB11 heterozygotes presenting as progressive intrahepatic cholestasis with low γ-glutamyltransferase. Hepatol Res 2018; 48:574-584. [PMID: 29316097 DOI: 10.1111/hepr.13055] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 01/01/2018] [Accepted: 01/05/2018] [Indexed: 02/08/2023]
Abstract
AIM The aim of this study was to analyze the pathogenicity of rare/novel synonymous or intronic variants identified in ABCB11 heterozygotes presenting as progressive intrahepatic cholestasis with low γ-glutamyltransferase. METHODS The enrolled variants were identified in ABCB11 between October 2009 and June 2016. The effects on pre-RNA splicing were analyzed by in silico tools and minigene splicing assay. RESULTS There were three intronic (c.908 + 5G > A, c.2815-8A > G, and c.612-15_-6del10bp) and two synonymous (c.1809G > A, p.K603 K and c.2418C > T, p.G806G) variants with unknown significance identified in ABCB11 of five ABCB11 heterozygotes. Parental studies were carried out for four patients, and revealed that the variants with unknown significance were compound heterozygous with other pathogenic variants. The five variants with unknown significance had minor allele frequency <0.1% or were absent from controls, and had positive prediction results by in silico tools. The effects on pre-RNA splicing were further confirmed by minigene splicing assay. c.908 + 5A caused abnormal splicing in at least 78.5 ± 3.8% of products using a cryptic splice site (ss) 22 nucleotides (nt) upstream of the wild-type (WT) 5'ss. Seven nucleotides of intron 22 upstream of the WT 3'ss was retained for all products from c.2815-8G. c.612-15_-6del caused exon 8 skipping in 24.8 ± 7.7% of products, and 55 nt of exon 8 downstream of the WT 3'ss removal in remaining products. c.1809A led to exon 15 skipping. c.2418 T removed exon 20 and 62 nt of exon 21 downstream of the WT 3'ss by using a cryptic ss. CONCLUSIONS We successfully identified five pathogenic synonymous or intronic variants with some common features. These features might help to choose the right variant for further functional assay.
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Affiliation(s)
- Neng-Li Wang
- Department of Pediatrics, Jinshan Hospital of Fudan University, Shanghai, China.,The Center for Pediatric Liver Diseases, Children's Hospital of Fudan University, Shanghai, China
| | - Yi-Ling Qiu
- The Center for Pediatric Liver Diseases, Children's Hospital of Fudan University, Shanghai, China
| | - Wen-Cai Guan
- The Central Laboratory, Jinshan Hospital of Fudan University, Shanghai, China
| | - Gang Li
- The Molecular Genetic Diagnosis Center, Shanghai Key Laboratory of Birth Defects, Pediatrics Research Institute, Children's Hospital of Fudan University, Shanghai, China
| | - Yi Lu
- The Center for Pediatric Liver Diseases, Children's Hospital of Fudan University, Shanghai, China
| | - Mei-Hong Zhang
- Department of Pediatrics, Jinshan Hospital of Fudan University, Shanghai, China
| | - Wei-Sha Luan
- Department of Pediatrics, Jinshan Hospital of Fudan University, Shanghai, China
| | - Jian-She Wang
- The Center for Pediatric Liver Diseases, Children's Hospital of Fudan University, Shanghai, China
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13
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Qiu Y, Gong J, Feng J, Wang R, Han J, Liu T, Lu Y, Li L, Zhang M, Sheps JA, Wang N, Yan Y, Li J, Chen L, Borchers CH, Sipos B, Knisely A, Ling V, Xing Q, Wang J. Defects in myosin VB are associated with a spectrum of previously undiagnosed low γ-glutamyltransferase cholestasis. Hepatology 2017; 65:1655-1669. [PMID: 28027573 PMCID: PMC5413810 DOI: 10.1002/hep.29020] [Citation(s) in RCA: 95] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Revised: 11/16/2016] [Accepted: 12/21/2016] [Indexed: 12/11/2022]
Abstract
Hereditary cholestasis in childhood and infancy with normal serum gamma-glutamyltransferase (GGT) activity is linked to several genes. Many patients, however, remain genetically undiagnosed. Defects in myosin VB (MYO5B; encoded by MYO5B) cause microvillus inclusion disease (MVID; MIM251850) with recurrent watery diarrhea. Cholestasis, reported as an atypical presentation in MVID, has been considered a side effect of parenteral alimentation. Here, however, we report on 10 patients who experienced cholestasis associated with biallelic, or suspected biallelic, mutations in MYO5B and who had neither recurrent diarrhea nor received parenteral alimentation. Seven of them are from two study cohorts, together comprising 31 undiagnosed low-GGT cholestasis patients; 3 are sporadic. Cholestasis in 2 patients was progressive, in 3 recurrent, in 2 transient, and in 3 uncategorized because of insufficient follow-up. Liver biopsy specimens revealed giant-cell change of hepatocytes and intralobular cholestasis with abnormal distribution of bile salt export pump (BSEP) at canaliculi, as well as coarse granular dislocation of MYO5B. Mass spectrometry of plasma demonstrated increased total bile acids, primary bile acids, and conjugated bile acids, with decreased free bile acids, similar to changes in BSEP-deficient patients. Literature review revealed that patients with biallelic mutations predicted to eliminate MYO5B expression were more frequent in typical MVID than in isolated-cholestasis patients (11 of 38 vs. 0 of 13). CONCLUSION MYO5B deficiency may underlie 20% of previously undiagnosed low-GGT cholestasis. MYO5B deficiency appears to impair targeting of BSEP to the canalicular membrane with hampered bile acid excretion, resulting in a spectrum of cholestasis without diarrhea. (Hepatology 2017;65:1655-1669).
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Affiliation(s)
- Yi‐Ling Qiu
- The Center for Pediatric Liver DiseasesChildren's Hospital of Fudan UniversityShanghaiChina
| | - Jing‐Yu Gong
- Department of PediatricsJinshan Hospital of Fudan UniversityShanghaiChina
| | - Jia‐Yan Feng
- Department of PathologyChildren's Hospital of Fudan UniversityShanghaiChina
| | | | - Jun Han
- University of Victoria−Genome BC Proteomics CentreUniversity of VictoriaVictoriaBritish ColumbiaCanada
| | - Teng Liu
- Department of PediatricsJinshan Hospital of Fudan UniversityShanghaiChina
| | - Yi Lu
- The Center for Pediatric Liver DiseasesChildren's Hospital of Fudan UniversityShanghaiChina
| | - Li‐Ting Li
- The Center for Pediatric Liver DiseasesChildren's Hospital of Fudan UniversityShanghaiChina
| | - Mei‐Hong Zhang
- Department of PediatricsJinshan Hospital of Fudan UniversityShanghaiChina
| | | | - Neng‐Li Wang
- Department of PediatricsJinshan Hospital of Fudan UniversityShanghaiChina
| | - Yan‐Yan Yan
- Department of PediatricsJinshan Hospital of Fudan UniversityShanghaiChina
| | - Jia‐Qi Li
- Department of PediatricsJinshan Hospital of Fudan UniversityShanghaiChina
| | - Lian Chen
- Department of PathologyChildren's Hospital of Fudan UniversityShanghaiChina
| | - Christoph H. Borchers
- University of Victoria−Genome BC Proteomics CentreUniversity of VictoriaVictoriaBritish ColumbiaCanada
| | - Bence Sipos
- Institute of General Pathology and NeuropathologyTübingen University HospitalTübingenGermany
| | - A.S. Knisely
- Institute of PathologyGraz Medical UniversityGrazAustria
| | - Victor Ling
- BC Cancer AgencyVancouverBritish ColumbiaCanada
| | - Qing‐He Xing
- Institutes of Biomedical Sciences of Fudan UniversityShanghaiChina
| | - Jian‐She Wang
- Department of PediatricsJinshan Hospital of Fudan UniversityShanghaiChina
- Department of Infectious DiseasesChildren's Hospital of Fudan UniversityShanghaiChina
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14
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Guideline for the Evaluation of Cholestatic Jaundice in Infants: Joint Recommendations of the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition and the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition. J Pediatr Gastroenterol Nutr 2017; 64:154-168. [PMID: 27429428 DOI: 10.1097/mpg.0000000000001334] [Citation(s) in RCA: 274] [Impact Index Per Article: 39.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Cholestatic jaundice in infancy affects approximately 1 in every 2500 term infants and is infrequently recognized by primary providers in the setting of physiologic jaundice. Cholestatic jaundice is always pathologic and indicates hepatobiliary dysfunction. Early detection by the primary care physician and timely referrals to the pediatric gastroenterologist/hepatologist are important contributors to optimal treatment and prognosis. The most common causes of cholestatic jaundice in the first months of life are biliary atresia (25%-40%) followed by an expanding list of monogenic disorders (25%), along with many unknown or multifactorial (eg, parenteral nutrition-related) causes, each of which may have time-sensitive and distinct treatment plans. Thus, these guidelines can have an essential role for the evaluation of neonatal cholestasis to optimize care. The recommendations from this clinical practice guideline are based upon review and analysis of published literature and the combined experience of the authors. The committee recommends that any infant noted to be jaundiced after 2 weeks of age be evaluated for cholestasis with measurement of total and direct serum bilirubin, and that an elevated serum direct bilirubin level (direct bilirubin levels >1.0 mg/dL or >17 μmol/L) warrants timely consideration for evaluation and referral to a pediatric gastroenterologist or hepatologist. Of note, current differential diagnostic plans now incorporate consideration of modern broad-based next-generation DNA sequencing technologies in the proper clinical context. These recommendations are a general guideline and are not intended as a substitute for clinical judgment or as a protocol for the care of all infants with cholestasis. Broad implementation of these recommendations is expected to reduce the time to the diagnosis of pediatric liver diseases, including biliary atresia, leading to improved outcomes.
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15
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Pan S, Li X, Jiang P, Jiang Y, Shuai L, He Y, Li Z. Variations of ABCB4 and ABCB11 genes are associated with primary intrahepatic stones. Mol Med Rep 2014; 11:434-46. [PMID: 25323205 DOI: 10.3892/mmr.2014.2645] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Accepted: 08/11/2014] [Indexed: 01/21/2023] Open
Abstract
Variations of the ABCB4 and ABCB11 genes affect the composition of bile and are associated with cholestasis and cholelithiasis. However, their roles in the formation of primary intrahepatic stones (PIS) remains to be elucidated. The aim of the present study was to determine whether there is an association between PIS and variations in these genes. Exon sequencing was performed in order to analyze the ABCB4 and ABCB11 genes of 176 patients with PIS and 178 healthy subjects. One mutation in ABCB4 (no. 69233, G>A) and two other mutations in ABCB11, reference single nucleotide polymorphism (rs)118109635 and rs497692, were identified in association with PIS (P<0.001, P=0.04 and P=0.02, respectively). A synonymous mutation at no. 69233 G>A was detected in exon 26 of ABCB4 in 23 heterozygous patients with PIS. This mutation was not detected in healthy individuals or in the Single Nucleotide Polymorphism Database. No. 69233 G>A in ABCB4 was not associated with altered protein expression but with a reduced rate of PIS recurrence (P=0.01). The missense mutation rs118109635 was located on exon 21 of ABCB11 and was associated with the increased expression of ABCB11 protein (P=0.032) as well as altered bile salt export pump function. Another synonymous mutation, rs497692 in exon 24 was reported to decrease ABCB11 protein expression (P=0.001). In addition, the mutations of ABCB11 were associated with preoperative jaundice (P<0.001 and P=0.03, respectively). Consistently decreased levels of ABCB11 protein were associated with recurrent episodes of cholangitis (P=0.006) and preoperative jaundice (P=0.015). By contrast, ABCB4 expression was not found to be associated with clinical manifestations of PIS.
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Affiliation(s)
- Shuguang Pan
- Institute of Hepatobiliary Surgery, Southwest Hospital, Third Military Medical University, Shapingba, Chongqing 400038, P.R. China
| | - Xiaowu Li
- Institute of Hepatobiliary Surgery, Southwest Hospital, Third Military Medical University, Shapingba, Chongqing 400038, P.R. China
| | - Peng Jiang
- Institute of Hepatobiliary Surgery, Southwest Hospital, Third Military Medical University, Shapingba, Chongqing 400038, P.R. China
| | - Yan Jiang
- Institute of Hepatobiliary Surgery, Southwest Hospital, Third Military Medical University, Shapingba, Chongqing 400038, P.R. China
| | - Ling Shuai
- Institute of Hepatobiliary Surgery, Southwest Hospital, Third Military Medical University, Shapingba, Chongqing 400038, P.R. China
| | - Yu He
- Institute of Hepatobiliary Surgery, Southwest Hospital, Third Military Medical University, Shapingba, Chongqing 400038, P.R. China
| | - Zhihua Li
- Institute of Hepatobiliary Surgery, Southwest Hospital, Third Military Medical University, Shapingba, Chongqing 400038, P.R. China
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16
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Dietrich CG, Geier A. Effect of drug transporter pharmacogenetics on cholestasis. Expert Opin Drug Metab Toxicol 2014; 10:1533-51. [PMID: 25260651 DOI: 10.1517/17425255.2014.963553] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
INTRODUCTION The liver is the central place for the metabolism of drugs and other xenobiotics. In the liver cell, oxidation and conjugation of compounds take place, and at the same time, bile formation helps in extrusion of these compounds via the biliary route. A large number of transporters are responsible for drug uptake into the liver cell and excretion into bile or efflux to the sinusoidal blood. AREAS COVERED Genetic variants of these transporters and their transactivators contribute to changes in drug handling and are also responsible for cholestatic syndromes of different severity. This review summarizes the current knowledge regarding the influence of these genetic changes. The review covers progressive hereditary cholestatic syndromes as well as recurrent or transient cholestatic syndromes such as drug-induced liver injury, intrahepatic cholestasis of pregnancy, and benign recurrent intrahepatic cholestasis. EXPERT OPINION Polymorphisms in transporter genes are frequent. For clinically relevant cholestatic syndromes, it often requires a combination of genetic variants or acquired triggers such as pregnancy or drug treatment. In combination with other pathogenetic aspects, genetic variants in drug transporters may contribute to our understanding of not only cholestatic diseases such as primary sclerosing cholangitis or primary biliary cirrhosis, but also the natural course of chronic liver disease in general.
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17
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Hu G, He P, Liu Z, Chen Q, Zheng B, Zhang Q. Diagnosis of ABCB11 gene mutations in children with intrahepatic cholestasis using high resolution melting analysis and direct sequencing. Mol Med Rep 2014; 10:1264-74. [PMID: 24969679 PMCID: PMC4121405 DOI: 10.3892/mmr.2014.2349] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Accepted: 04/28/2014] [Indexed: 12/17/2022] Open
Abstract
Intrahepatic cholestasis represents a heterogeneous group of disorders that begin during childhood, most commonly manifesting as neonatal cholestasis, and lead to ongoing liver dysfunction in children and adults. For children, inherited pathogenic factors of cholestasis have gained increasing attention owing to the rapid development of molecular biology technology. However, these methods have their advantages and disadvantages in terms of simplicity, sensitivity, specificity, time required and expense. In the present study, an effective, sensitive and economical method is recommended, termed high-resolution melting (HRM) analysis and direct sequencing, based on general polymerase chain reaction, to detect mutations in disease-causing genes. As one type of inherited intrahepatic cholestasis, progressive familial intrahepatic cholestasis type 2 (PFIC2) is caused by pathogenic mutations in the ABCB11 gene, HRM was used to detect mutations in the ABCB11 gene in the present study, and the diagnosis for PFIC2 was made by comprehensive analysis of genetic findings and clinical features. Furthermore, the characteristics of mutations and single nucleotide polymorphisms (SNPs) in the ABCB11 gene were elucidated. A total of 14 types of mutations/polymorphisms were identified in 20 patients from mainland China, including six missense mutations (p.Y337H, p.Y472C, p.R696W, p.Q931P, p.D1131V and p.H1198R), one nonsense mutation (p.R928X) and seven SNPs (p.D36D/rs3815675, p.F90F/rs4148777, p.Y269Y/rs2287616, p.I416I/rs183390670, p.V444A/rs2287622, p.A865V/rs118109635 and p.A1028A/rs497692). Five mutations were novel. The majority of the mutations were different from those detected in other population groups. A total of 4/20 patients (1/5) were diagnosed to be PFIC2 by combining genetic findings with the clinical features. Polymorphisms V444A and A1028A, with an allele frequency of 74.5 and 67.2%, respectively, were highly prevalent in the mainland Chinese subjects. No differences were found between the patients with cholestasis and the control subjects. Efficient genetic screening facilitates the clinical diagnosis of genetic disorders. The present study demonstrated that HRM analysis was efficient and effective in detecting mutations and expanded the known spectrum of ABCB11 gene mutations.
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Affiliation(s)
- Guorui Hu
- Medical College of Nanjing University, Nanjing, Jiangsu 210093, P.R. China
| | - Ping He
- Medical College of Nanjing University, Nanjing, Jiangsu 210093, P.R. China
| | - Zhifeng Liu
- Medical College of Nanjing University, Nanjing, Jiangsu 210093, P.R. China
| | - Qian Chen
- Department of Digestive Disease, Nanjing Children's Hospital, Nanjing Medical University, Nanjing, Jiangsu 210008, P.R. China
| | - Bixia Zheng
- Department of Digestive Disease, Nanjing Children's Hospital, Nanjing Medical University, Nanjing, Jiangsu 210008, P.R. China
| | - Qihua Zhang
- Department of Digestive Disease, Nanjing Children's Hospital, Nanjing Medical University, Nanjing, Jiangsu 210008, P.R. China
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