A Precision Medicine Approach to Assess Protein Function Loss and the Potential for CFTR Function Restoration in Cystic Fibrosis and Related Disorders

Inclusion Criteria: * Adult or pediatric patients diagnosed with cystic fibrosis (CF) who have, on the first allele, a missense mutation or a small deletion (not resulting in a frameshift) that has not been functionally characterized or for which responsiveness to currently available therapies is limited or unknown, AND a second allele carrying another uncharacterized mutation, a stop-gain mutation, a class II mutation, or a large deletion of the CFTR gene; OR * Pediatric patients with Cystic Fibrosis Screen Positive, Inconclusive Diagnosis (CFSPID), meeting the following definition: "an asymptomatic newborn with a positive CF newborn screening (NBS) result and a sweat chloride concentration \<30 mmol/L and two CFTR variants, at least one of which has unclear phenotypic consequences; or an intermediate sweat chloride concentration (30-59 mmol/L) and one or no CF-causing variants"; OR * Adult or pediatric patients with CFTR-related disorders (CFTR-RD) meeting the following criteria: a CFTR-RD-associated phenotype, evidence of CFTR dysfunction, and exclusion of a diagnosis of cystic fibrosis; OR * Adult patients aged ≥18 years carrying a single CF-causing variant and diagnosed with idiopathic bronchiectasis. * Written informed consent/assent for study participation and personal data processing must be obtained before the initiation of data collection and any study-related procedures. Exclusion Criteria: * Failure to meet the eligibility criteria for study enrollment. * Failure to provide signed informed consent/assent for study participation or for the processing of personal data.