title: Increased frequency of double and triple heterozygous gene variants in children with intrahepatic cholestasis.
abstract: OBJECTIVE
  Single gene mutations cause syndromes of intrahepatic cholestasis, but previous multi-gene mutation screening in children with idiopathic cholestasis failed to fulfill diagnostic criteria in approximately two-thirds of children. In adults with fibrosing cholestatic disease, heterozygous ABCB4 mutations were present in 34% of patients. Here, we hypothesized that children with idiopathic cholestasis have a higher frequency of heterozygous non-synonymous gene sequence variants.
  
  
  METHODS
  We analyzed the frequency and types of variants in 717 children in whom high-throughput sequencing of the genes SERPINA1, JAG1, ATP8B1, ABCB11 and ABCB4 was performed as part of an evaluation for idiopathic intrahepatic cholestasis cholestasis. The frequency of non-synonymous variants (NSV) was compared with those of 1092 control subjects enrolled in the 1000 Genome Project.
  
  
  RESULTS
  The frequency of NSV in single genes was similar between disease (25%) and controls (26%, P = 0.518). In contrast, double or triple NSV in two or more genes were more frequent in disease (n = 7%) than controls (n = 4.7%, P = 0.028). Detailed review of clinical and laboratory information in a subgroup of double or triple heterozygous patients revealed variable γ-glutamyltransferase levels and severity of pruritus, with liver biopsies showing stage 2-3 fibrosis.
  
  
  CONCLUSIONS
  Children with idiopathic intrahepatic cholestasis have a higher frequency of double or triple NSV in SERPINA1, JAG1, ATPB1, ABCB11 or ABCB4. These findings raise the potential role for gene-gene relationships in determining the phenotype of cholestatic liver disease in children.
authors.affiliation: Divisions of Pediatric Gastroenterology, Hepatology and Nutrition, Pediatric Liver Care Center of Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.|Pediatric Liver Care Center of Cincinnati Children's Hospital Medical Center, Department of Pediatrics of the University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.
authors.forename: Monique L
authors.initials: ML
authors.lastname: Goldschmidt
authors.affiliation: Divisions of Pediatric Gastroenterology, Hepatology and Nutrition, Pediatric Liver Care Center of Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.|Pediatric Liver Care Center of Cincinnati Children's Hospital Medical Center, Department of Pediatrics of the University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.
authors.forename: Reena
authors.initials: R
authors.lastname: Mourya
authors.affiliation: Human Genetics, Pediatric Liver Care Center of Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.|Pediatric Liver Care Center of Cincinnati Children's Hospital Medical Center, Department of Pediatrics of the University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.
authors.forename: Jessica
authors.initials: J
authors.lastname: Connor
authors.affiliation: Bioinformatics, Pediatric Liver Care Center of Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.|Pediatric Liver Care Center of Cincinnati Children's Hospital Medical Center, Department of Pediatrics of the University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.
authors.forename: Phillip
authors.initials: P
authors.lastname: Dexheimer
authors.affiliation: Bioinformatics, Pediatric Liver Care Center of Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.|Pediatric Liver Care Center of Cincinnati Children's Hospital Medical Center, Department of Pediatrics of the University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.
authors.forename: Rebekah
authors.initials: R
authors.lastname: Karns
authors.affiliation: Divisions of Pediatric Gastroenterology, Hepatology and Nutrition, Pediatric Liver Care Center of Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.|Pediatric Liver Care Center of Cincinnati Children's Hospital Medical Center, Department of Pediatrics of the University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.
authors.forename: Alexander
authors.initials: A
authors.lastname: Miethke
authors.affiliation: Pediatric Pathology, Pediatric Liver Care Center of Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.|Pediatric Liver Care Center of Cincinnati Children's Hospital Medical Center, Department of Pediatrics of the University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.
authors.forename: Rachel
authors.initials: R
authors.lastname: Sheridan
authors.affiliation: Human Genetics, Pediatric Liver Care Center of Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.|Pediatric Liver Care Center of Cincinnati Children's Hospital Medical Center, Department of Pediatrics of the University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.
authors.forename: Kejian
authors.initials: K
authors.lastname: Zhang
authors.affiliation: Divisions of Pediatric Gastroenterology, Hepatology and Nutrition, Pediatric Liver Care Center of Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.|Pediatric Liver Care Center of Cincinnati Children's Hospital Medical Center, Department of Pediatrics of the University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.
authors.forename: Jorge A
authors.initials: JA
authors.lastname: Bezerra
keywords: children; cirrhosis; jaundice; liver; mutations