Molecular analysis of the carboxy terminus of the beta and gamma subunits of the epithelial sodium channel in patients with end-stage renal disease.
BACKGROUND
Mutations in the carboxy termini of the beta subunit (hbetaENaC) and the gamma subunit (hgammaENaC) of the human epithelial sodium channel have been identified in patients with Liddle syndrome. Moreover polymorphisms have been described in these genes, the clinical relevance of which for progression to end-stage renal disease (ESRD) is unknown. We, therefore, have screened ESRD patients for putative variants of these genes.


METHODS
We investigated 256 chronic hemodialysis patients, including 123 patients with a history of hypertension as a cause of ESRD. Screening for mutations in the carboxy termini of hbetaENaC and hgammaENaC was accomplished by polymerase chain reaction amplification followed by single-strand conformation polymorphism analysis.


RESULTS
In 231 patients single-strand conformation polymorphism analysis of the polymerase chain reaction fragments of the hbetaENaC and hgammaENaC genes showed a similar migration pattern as compared with negative control subjects. In 25 patients a band shift was observed. However, sequence analysis in all these patients revealed wild-type sequence.


CONCLUSIONS
The present study demonstrates the absence of genetic variants in the carboxy terminus of the hbetaENaC and hgammaENaC genes in Austrian patients with ESRD maintained on chronic hemodialysis treatment. Thus, mutations in these genes are unlikely to be associated with ESRD.
Födinger
M
M
Department of Laboratory Medicine, Division of Molecular Biology, University of Vienna, Austria. manuela.foedinger@akh-wien.ac.at
Schedler
D
D
Fritsche-Polanz
R
R
Hörl
W H
WH
Sunder-Plassmann
G
G
D017931:DNA Primers; D053503:Epithelial Sodium Channels; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000235:genetics* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D018807:Polymorphism, Single-Stranded Conformational; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015222:Sodium Channels / Q000235:genetics* / Q000378:metabolism
D017931:DNA Primers; D053503:Epithelial Sodium Channels; C507048:SCNN1B protein, human; D015222:Sodium Channels