Identification of EpCAM as the gene for congenital tufting enteropathy

Gastroenterology. 2008 Aug;135(2):429-37. doi: 10.1053/j.gastro.2008.05.036. Epub 2008 May 15.

Abstract

Background & aims: Congenital tufting enteropathy (CTE) is a rare autosomal recessive diarrheal disorder presenting in the neonatal period. CTE is characterized by intestinal epithelial cell dysplasia leading to severe malabsorption and significant morbidity and mortality. The pathogenesis and genetics of this disorder are not well understood. The objective of this study was to identify the gene responsible for CTE.

Methods: A family with 2 children affected with CTE was identified. The affected children are double second cousins providing significant statistical power for linkage. Using Affymetrix 50K single nucleotide polymorphism (SNP) chips, genotyping was performed on only 2 patients and 1 unaffected sibling. Direct DNA sequencing of candidate genes, reverse-transcription polymerase chain reaction, immunohistochemistry, and Western blotting were performed on specimens from patients and controls.

Results: SNP homozygosity mapping identified a unique 6.5-Mbp haplotype of homozygous SNPs on chromosome 2p21 where approximately 40 genes are located. Direct sequencing of genes in this region revealed homozygous G>A substitution at the donor splice site of exon 4 in epithelial cell adhesion molecule (EpCAM) of affected patients. Reverse-transcription polymerase chain reaction of duodenal tissue demonstrated a novel alternative splice form with deletion of exon 4 in affected patients. Immunohistochemistry and Western blot of patient intestinal tissue revealed decreased expression of EpCAM. Direct sequencing of EpCAM from 2 additional unrelated patients revealed novel mutations in the gene.

Conclusions: Mutations in the gene for EpCAM are responsible for CTE. This information will be used to gain further insight into the molecular mechanisms of this disease.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alternative Splicing
  • Antigens, Neoplasm / analysis
  • Antigens, Neoplasm / genetics*
  • Blotting, Western
  • Case-Control Studies
  • Cell Adhesion Molecules / analysis
  • Cell Adhesion Molecules / genetics*
  • Chromosomes, Human, Pair 2*
  • DNA Mutational Analysis
  • Diarrhea, Infantile / congenital
  • Diarrhea, Infantile / genetics*
  • Diarrhea, Infantile / immunology
  • Diarrhea, Infantile / pathology
  • Duodenum / immunology*
  • Duodenum / pathology
  • Epithelial Cell Adhesion Molecule
  • Exons
  • Gene Expression Profiling / methods
  • Genetic Predisposition to Disease
  • Haplotypes
  • Homozygote
  • Humans
  • Immunohistochemistry
  • Infant
  • Infant, Newborn
  • Intestinal Diseases / congenital
  • Intestinal Diseases / genetics*
  • Intestinal Diseases / immunology
  • Intestinal Diseases / pathology
  • Intestinal Mucosa / immunology
  • Intestinal Mucosa / pathology
  • Oligonucleotide Array Sequence Analysis
  • Pedigree
  • Polymorphism, Single Nucleotide
  • Reverse Transcriptase Polymerase Chain Reaction

Substances

  • Antigens, Neoplasm
  • Cell Adhesion Molecules
  • EPCAM protein, human
  • Epithelial Cell Adhesion Molecule