Per l’analisi mutazionale dei geni ENaC sono stati studiati 84 pazienti con FC tipica o atipica, con almeno 1 mutazione del CFTR non identificata. La frequenza cumulativa delle variazioni trovate è risultata essere 0,25, molto simile a quella di un precedente studio (0,30). Dopo l’analisi di frequenza e gli studi su computer, sono state selezionate 4 mutazioni (7 alleli) probabilmente causa di patologia: p.Pro37Leu (SCNN1A), p.Glu438Gly (SCNN1B), p.Ser82Cys (SCNN1B) e p.Glu197Lys (SCNN1G). I meccanismi di funzionamento di queste mutazioni sono stati studiati su cellule primarie FC e cellule FRT (Fisher Rat Thyroid). E’ risultato possibile ridurre il riassorbimento di fluido dipendente da ENaC mediante inibitori di peptidasi (enzimi) extracellulari o trattamenti “epigenetici”, che si realizzano con modalità solo in parte chiarite (inibizione della trascrizione o altro).
All treatments resulted to be able to reduce channel activity. In case of epigenetic treatments in stable cell lines, the molecular basis for this reduction seems to be the transcription inhibition, whereas in primary cells a different mechanism, to be clarified, seems effective. For mutational analysis of ENaC genes, 84 patients with CFof CF-like diseases, with at least one unidentified CFTR mutation, were analyzed. The cumulative frequency of variations is in agreement with a previously published frequency of 0.30. After frequency and in silico analysis, 4 probably damaging ENaC mutations (7 alleles) were selected: p.Pro37Leu (SCNN1A), p.Glu438Gly (SCNN1B), p.Ser82Cys (SCNN1B) and p.Glu197Lys (SCNN1G). We have been using FRT cells expressing tagged human ENaC genes as cellular models for the study of functional effects of these 4 variations. As a lot of CF or CF-like patients resulted negative for ENaC gene mutations, to obtain more information about a possible involvement of other genes, a whole exome sequencing by a NGS technology is ongoing. These results add new insight into CF molecular mechanisms, partially extending the pathogenetic mechanism to ENaC molecular lesions.