Clinical features and genotype-phenotype correlations in children with progressive familial intrahepatic cholestasis type 3 related to ABCB4 mutations

Carla Colombo, Pietro Vajro, Dario Degiorgio, Domenico A. Coviello, Lucy Costantino, Luigi Tornillo, Valentina Motta, Dario Consonni, Giuseppe Maggiore

Research output: Contribution to journalArticlepeer-review

Abstract

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 (γ-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 γ-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.

Original languageEnglish
Pages (from-to)73-83
Number of pages11
JournalJournal of Pediatric Gastroenterology and Nutrition
Volume52
Issue number1
DOIs
Publication statusPublished - Jan 2011

Keywords

  • ABCB4 alias MDR3 gene
  • biliary cirrhosis
  • child
  • chronic intrahepatic cholestasis
  • liver disease
  • liver transplantation
  • progressive familial intrahepatic cholestasis

ASJC Scopus subject areas

  • Gastroenterology
  • Pediatrics, Perinatology, and Child Health

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