She was found to have a mutation in the SPINK1 gene, IVS3+184T>A, and one cystic fibrosis-causing mutation (G551D) prompting full gene sequencing of the CFTR, revealing an additional duplication of exon 19.
We randomly assigned 39 adults with cystic fibrosis and at least one G551D-CFTR allele to receive oral VX-770 every 12 hours at a dose of 25, 75, or 150 mg or placebo for 14 days (in part 1 of the study) or VX-770 every 12 hours at a dose of 150 or 250 mg or placebo for 28 days (in part 2 of the study).
We generated G551DCF mice transgenically expressing the human CFTR gene in two tissue compartments previously demonstrated to mediate a CFTR-dependent inflammatory response: lung epithelium and alveolar macrophages.
The most common mutations in CFTR are a deletion of a phenylalanine residue at position 508 (ΔF508-CFTR, 70-80 % of CF phenotypes) and a Gly551Asp substitution (G551D-CFTR, 4-5 % of alleles), which lead to decreased or almost abolished Cl(-) channel function, respectively.
Additive improvement in G551D CFTR-mediated Cl<sup>-</sup> secretion suggests that resveratrol could enhance ivacaftor therapy in these patients and improve CF-related rhinosinusitis.
The potentiator Kalydeco™ (also known as Ivacaftor or VX-770), developed by Vertex Pharmaceuticals, has been recently approved by the US FDA and the European Medicines Agency (EMA) for the treatment of CF patients carrying at least one CFTR allele with the p.Gly551Asp mutation (2-5 % of all patients).
The CF-associated mutation G551D, by introducing a bulky and negatively charged side chain into site 2, completely abolishes ATP-induced openings of CFTR.
For adults and children aged 6 years and older with CF due to gating mutations other than G551D or R117H, the guideline panel made a conditional recommendation for treatment with IVA.
Ivacaftor, a cystic fibrosis transmembrane conductance regulator (CFTR) potentiator, is approved for the treatment of patients with cystic fibrosis aged 6 years or older with Gly551Asp-CFTR.
Ivacaftor corrects the cystic fibrosis transmembrane conductance regulator (CFTR) gating defect associated with G551D mutation and is quickly becoming an important treatment in patients with cystic fibrosis (CF) due to this genetic mutation.
The present study characterized in a sample of patients with an established clinical diagnosis of CF (asthma, repeated bronchopneumonia, disorders of nutritional status, etc.) the most frequent mutation (deltaF508) in the North region of Brazil and is also the first report of the G551D mutation.
Curcumin cross-linked two CF mutant channels (Delta F508 and G551D) as well as a variety of deletion constructs that lack the major cytoplasmic domains.
The G551D Observational Study enrolled a longitudinal observational cohort of US patients with CF aged 6 years and older with at least 1 copy of the G551D mutation.
Previous work indicates that ivacaftor improves cystic fibrosis transmembrane conductance regulator (CFTR) activity and lung function in people with cystic fibrosis and G551D-CFTR mutations but does not reduce density of bacteria or markers of inflammation in the airway.
Although ivacaftor is currently only licensed for use in approximately 5% of the CF population (those who have at least one Gly551Asp mutation), the developmental pathway established by ivacaftor paves the way for other CFTR modulators that may benefit many more patients.
Ivacaftor improves QOL in the R, P, and S domains in G551DCF patients, although QOL instruments validated for CRS may not translate well to CF CRS patients because symptom burden was surprisingly low.
VX-770 also increased Cl(-) secretion in cultured human CF bronchial epithelia (HBE) carrying the G551D gating mutation on one allele and the F508del processing mutation on the other allele by approximately 10-fold, to approximately 50% of that observed in HBE isolated from individuals without CF.