CFTR gating mutations (GMs) result in CFTR that is present at the cell surface but non-functional. Patients with the G551D mutation, the most prevalent worldwide have been well studied. Italian GM patients have mainly non-G551D mutations. We studied their epidemiology and clinical characteristics in the period spanning the pre/post ivacaftor introduction to the Italian market.
Data from the Italian CF Registry were used to describe patients with GMs and compare them with F508del homozygous (F/F) patients.
186 patients with GMs (median (range) age 21.96 (0.13 to 63.38) years) were identified among the 5,552 patients included in the study (3.3%). They had lower sweat chloride values (SCV) at diagnosis than the F/F and lower ratio of males. In the GM group, examining the data of the years 2012 and 2017 and comparing with F/F, lung infection by Staphylococcus aureus and diabetes became less prevalent, and better FEV and nutritional status were observed in 2017. The cross-sectional evaluation year-by-year from 2012 to 2017 of the GM group showed improving trends in lung function and BMI, and decreasing prevalence of diabetes compared with F/F. Longitudinal evaluation of GM patients showed improvement in ppFEV and nutrition in the 2012-2017 period. These variations correspond to the introduction of treatment with the CFTR potentiator ivacaftor (2014/2015).
Italian patients with GMs are few and are characterised by milder phenotypes than F/F patients. Improved outcomes are likely influenced by treatment with ivacaftor. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.