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 (h beta EN aC) and the gamma subunit (h gamma ENaC) of the human epithelial sodium cha nnel have been identified in patients with Liddle syndrome. Moreover polymo rphisms have been described in these genes, the clinical relevance of which for progression to end-stage renal disease (ESRD) is unknown. We, therefor e, have screened ESRD patients for putative variants of these genes, Method s: We investigated 256 ch ron ic hemodialysis patients, including 123 patie nts with a history of hypertension as a cause of ESRD. Screening for mutati ons in the carboxy termini of h beta ENaC and h gamma ENaC was accomplished by polymerase chain reaction amplification followed by single-strand confo rmation polymorphism analysis. Results: In 231 patients single-strand confo rmation polymorphism analysis of the polymerase chain reaction fragments of the h beta ENaC and h gamma ENaC 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-t ype sequence, Conclusions: The present study demonstrates the absence of ge netic variants in the carboxy terminus of the h beta ENaC and h gamma NaC g enes in Austrian patients with ESRD maintained on chronic hemodialysis trea tment, Thus, mutations in these genes are unlikely to be associated with ES RD.