Absence of dysfunctional ileal sodium-bile acid cotransporter gene mutations in patients with adult-onset idiopathic bile acid malabsorption.
BACKGROUND: A congenital form of idiopathic intestinal bile acid malabsorption (IBAM) has been associated with dysfunctional mutations in the ileal apical sodium-dependent bile acid transporter (ASBT). The aim of this study was to determine whether mutations in the ASBT gene (SLC10A2) predispose to the development of adult-onset idiopathic bile acid malabsorption and chronic watery diarrhea. METHODS: Genomic DNA was obtained from 13 adult IBAM patients previously diagnosed on the basis of clinical data, response to cholestyramine, and abnormal 75Se-homocholic acid taurine (SeHCAT) test values. The ASBT gene was screened for the presence of mutations or polymorphisms by single-stranded conformation polymorphism analysis (SSCP) and DNA sequencing. RESULTS: ASBT gene polymorphisms were detected in 5 of the 13 adult IBAM patients. Four patients were heterozygous for a common polymorphism in exon 3, leading to an alanine to serine substitution at codon 171 (A171S). An additional subject was heterozygous for a polymorphism in exon 1 that causes a valine to isoleucine substitution at codon 98 (V981). These functional polymorphisms were also found in unaffected subjects and do not appear to affect ASBT function. CONCLUSIONS: Adult-onset IBAM is not directly related to dysfunctional mutations in the coding region or intron/exon junctions of the SLC10A2 gene. In the absence of apparent ileal disease or intestinal motility defects, inappropriate down-regulation of the ileal bile acid transporter or defects in ileocyte transfer of bile acids into the portal circulation could explain this form of adult IBAM.[1]References
- Absence of dysfunctional ileal sodium-bile acid cotransporter gene mutations in patients with adult-onset idiopathic bile acid malabsorption. Montagnani, M., Love, M.W., Rössel, P., Dawson, P.A., Qvist, P. Scand. J. Gastroenterol. (2001) [Pubmed]
Annotations and hyperlinks in this abstract are from individual authors of WikiGenes or automatically generated by the WikiGenes Data Mining Engine. The abstract is from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.About WikiGenesOpen Access LicencePrivacy PolicyTerms of Useapsburg
