title: Taking the next step forward - Diagnosing inherited infantile cholestatic disorders with next generation sequencing.
abstract: Identifying rare genetic forms of infantile cholestasis is challenging due to their similar clinical presentation and their diverse etiology. After exclusion of common non-genetic causes a huge list of rare differential diagnosis remains to be solved. More than 90 genes are associated with monogenic forms of infantile cholestasis, thus preventing routine genetic workup by Sanger sequencing. Here we demonstrate a next generation sequencing approach to discover the underlying cause in clinically well characterized patients in whom common causes of infantile cholestasis have been excluded. After validation of the analytical sensitivity massive parallel sequencing was performed for 93 genes in six prospectively studied patients. Six novel mutations (PKHD1: p.Thr777Met, p.Tyr2260Cys; ABCB11: p.Val1112Phe, c.611+1G > A, p.Gly628Trpfs*3 and NPC1: p.Glu391Lys) and two known pathogenic mutations were detected proving our multi gene panel for infantile cholestasis to be a sensitive and specific method overcoming the complexity of the phenotype-based, candidate gene approach. Three exemplary clinical cases of infants with cholestasis are presented and discussed in the context of their genetic and histopathological findings (autosomal recessive polycystic kidney disease, atypical PFIC and Niemann-Pick syndrome type C1). These case reports highlight the critical impact of integrating clinical, histopathological and genetic data during the process of multi gene panel testing to ultimately pinpoint rare genetic diagnoses.
authors.affiliation: Center for and Institute of Human Genetics, University of Regensburg, Franz-Josef-Strauß-Allee 11, 93053 Regensburg, Germany. Electronic address: saskia.herbst@ukr.de.
authors.forename: S M
authors.initials: SM
authors.lastname: Herbst
authors.affiliation: Center for and Institute of Human Genetics, University of Regensburg, Franz-Josef-Strauß-Allee 11, 93053 Regensburg, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Schirmer
authors.affiliation: University Medical Center Ulm, Department of Pediatrics and Adolescent Medicine, Ulm, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Posovszky
authors.affiliation: Department of Pediatrics and Adolescent Medicine, Evangelisches Waldkrankenhaus Spandau, Berlin, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Jochum
authors.affiliation: Center for and Institute of Human Genetics, University of Regensburg, Franz-Josef-Strauß-Allee 11, 93053 Regensburg, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Rödl
authors.affiliation: Department of Pathology, University of Regensburg, Germany.
authors.forename: J A
authors.initials: JA
authors.lastname: Schroeder
authors.affiliation: University of Ulm, Institute of Pathology, Ulm, Germany.
authors.forename: T F
authors.initials: TF
authors.lastname: Barth
authors.affiliation: Center for and Institute of Human Genetics, University of Regensburg, Franz-Josef-Strauß-Allee 11, 93053 Regensburg, Germany.
authors.forename: U
authors.initials: U
authors.lastname: Hehr
authors.affiliation: KUNO - Children's University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, 93053 Regensburg, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Melter
authors.affiliation: KUNO - Children's University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, 93053 Regensburg, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Vermehren
mesh_terms: D000074020:ATP Binding Cassette Transporter, Subfamily B, Member 11; D018528:ATP-Binding Cassette Transporters / Q000235:genetics*; D002352:Carrier Proteins / Q000235:genetics*; D002779:Cholestasis / Q000175:diagnosis* / Q000235:genetics; D020022:Genetic Predisposition to Disease; D005820:Genetic Testing / Q000379:methods; D059014:High-Throughput Nucleotide Sequencing / Q000379:methods*; D006801:Humans; D007223:Infant; D047908:Intracellular Signaling Peptides and Proteins; D008562:Membrane Glycoproteins / Q000235:genetics*; D009154:Mutation; D000077296:Niemann-Pick C1 Protein; D010641:Phenotype; D011446:Prospective Studies; D035583:Rare Diseases / Q000175:diagnosis / Q000235:genetics; D011956:Receptors, Cell Surface / Q000235:genetics*; D012680:Sensitivity and Specificity; D017422:Sequence Analysis, DNA / Q000379:methods*
chemical_list: C093491:ABCB11 protein, human; D000074020:ATP Binding Cassette Transporter, Subfamily B, Member 11; D018528:ATP-Binding Cassette Transporters; D002352:Carrier Proteins; D047908:Intracellular Signaling Peptides and Proteins; D008562:Membrane Glycoproteins; C106881:NPC1 protein, human; D000077296:Niemann-Pick C1 Protein; C451750:PKHD1 protein, human; D011956:Receptors, Cell Surface
keywords: Hepatic fibrosis; Infantile cholestasis; Massive parallel sequencing; Next generation sequencing; Niemann–Pick-syndrome; PFIC; PKHD1