TY - JOUR
T1 - Nucleotide sequence of the na+/h+ exchanger-8 in patients with congenital sodium diarrhea.
AU - Baum, M
AU - Martin, MG
AU - Booth, Ian
AU - Holmberg, C
AU - Twombley, K
AU - Zhang, Q
AU - Gattineni, J
AU - Moe, O
PY - 2011/11/1
Y1 - 2011/11/1
N2 - 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.
AB - 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.
U2 - 10.1097/MPG.0b013e318227ad6e
DO - 10.1097/MPG.0b013e318227ad6e
M3 - Article
C2 - 21666503
SN - 1536-4801
VL - 53
SP - 474
EP - 477
JO - Journal of Pediatric Gastroenterology and Nutrition
JF - Journal of Pediatric Gastroenterology and Nutrition
IS - 5
ER -