Nucleotide sequence of the na+/h+ exchanger-8 in patients with congenital sodium diarrhea.

Research output: Contribution to journalArticle

Authors

  • M Baum
  • MG Martin
  • C Holmberg
  • K Twombley
  • Q Zhang
  • J Gattineni
  • O Moe

Colleges, School and Institutes

Abstract

ABSTRACT: Sodium absorption by the intestine is mediated by brush border Na/H exchangers, which include the NHE3 and NHE8 isoforms. We demonstrated a maturational decrease in NHE8 and increase in NHE3 in mouse intestine mRNA abundance and brush border membrane protein abundance, indicating a developmental switch of isoforms. Congenital sodium diarrhea is a rare autosomal recessive disorder characterized by polyhydramnios, hyponatremia, metabolic acidosis, and diarrhea with a high sodium content. Previous studies using intestinal brush border membrane vesicles from patients with this disorder have demonstrated a decrease in Na/H exchanger activity. Because some patients with congenital sodium diarrhea improve with age and knowing the developmental switch from NHE8 to NHE3, NHE8 may be a candidate gene for this disorder. We sequenced NHE8 from 5 patients with this disorder and found no disease-causing homozygous mutations. Although brush border membrane Na/H exchange activity may be decreased, exonic mutations in NHE8 cannot account for this disorder in these subjects.

Details

Original languageEnglish
Pages (from-to)474-7
Number of pages4
JournalJournal of Pediatric Gastroenterology and Nutrition
Volume53
Issue number5
Publication statusPublished - 1 Nov 2011

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