Molecular analysis of the fructose transporter gene (GLUT5) in isolated fructose malabsorption.
- 15 November 1996
- journal article
- Published by American Society for Clinical Investigation in JCI Insight
- Vol. 98 (10), 2398-2402
- https://doi.org/10.1172/jci119053
Abstract
Fructose, a naturally occurring monosaccharide, is increasingly used as an added sweetener in processed foods in the form of high fructose corn syrup. Increased fructose intake combined with the identification of children with clinical evidence of isolated fructose malabsorption (IFM) has stimulated interest in possible disorders of fructose absorption. The intestinal absorption of fructose is carried out by the facilitative hexose transporter, which has been designated as GLUT5. Functional properties and tissue distribution of GLUT5 suggest that IFM might be due to mutations in the GLUT5 gene. To test this hypothesis, we screened the GLUT5 gene for mutations in a group of eight patients with IFM and in one subject with global malabsorption, as compared with 15 healthy parents of subjects and up to 6 unrelated controls. No mutations were found in the protein coding region of this gene in any of the subjects. A single G to A substitution in the 5' untranslated region of exon 1 was identified in the subject with global malabsorption. This subject and her healthy mother were heterozygous for the variant sequence, suggesting that it was unlikely to be clinically significant. In addition, sequence analysis of each of the 12 GLUT5 exons was performed in the index case and confirmed the negative single-strand conformation polymorphism findings. These studies demonstrate that IFM does not result from the expression of mutant GLUT5 protein.Keywords
This publication has 22 references indexed in Scilit:
- Defects in Na+/glucose cotransporter (SGLT1) trafficking and function cause glucose-galactose malabsorptionNature Genetics, 1996
- Mammalian Facilitative Glucose Transporter Family: Structure and Molecular RegulationAnnual Review of Physiology, 1992
- Role of juice carbohydrate malabsorption in chronic nonspecific diarrhea in childrenThe Journal of Pediatrics, 1992
- Human intestinal glucose transporter expression and localization of GLUT5American Journal of Physiology-Cell Physiology, 1992
- Mammalian Glucose Transporters: Structure and Molecular RegulationPublished by Elsevier BV ,1991
- Human facilitative glucose transporters. Isolation, functional characterization, and gene localization of cDNAs encoding an isoform (GLUT5) expressed in small intestine, kidney, muscle, and adipose tissue and an unusual glucose transporter pseudogene-like sequence (GLUT6).Journal of Biological Chemistry, 1990
- Isolated fructose malabsorption.Archives of Disease in Childhood, 1990
- Rapid and sensitive detection of point mutations and DNA polymorphisms using the polymerase chain reactionGenomics, 1989
- Detection of polymorphisms of human DNA by gel electrophoresis as single-strand conformation polymorphisms.Proceedings of the National Academy of Sciences, 1989
- Detection of fructose malabsorption by breath hydrogen test in a child with diarrheaThe Journal of Pediatrics, 1983