The CFTR gene variants in paediatric nasal polyposis: a study in the Italian population

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a relatively uncommon condition in the paediatric population, with a prevalence estimated at 0.1-0.8%, compared to approximately 4% in adults (1, 2). The early onset of CRSwNP emphasises the significant role of genetic factors in its pathophysiology (3). Approximately 20% of paediatric patients with CRSwNP are associated with systemic genetic disorders, with cystic fibrosis (CF) being the most prevalent (2). CF is characterised by a dysfunction of the CF transmembrane conductance regulator (CFTR) protein. Over 2,000 distinct CFTR variants have been identified, resulting in varying organ involvement and disease severity. In 2000, the World Health Organization introduced the term "CFTR-related disorders" (CFTR-RDs) to include clinical entities associated with CFTR dysfunction that do not meet the diagnostic criteria for CF (4). CFTR-RDs include congenital bilateral absence of the vas deferens (CBAVD), recurrent pancreatitis (RP), and disseminated bronchiectasis (DB). However, recent studies emphasised a significant prevalence of heterozygous CFTR pathogenic variants in paediatric and adult CRSwNP populations without CF (4-8). We assessed the prevalence of CFTR variants in a paediatric population with CRSwNP.