Clinical and genetic characteristics of diseases caused by CFTR gene mutations in 15 Chinese children: a retrospective analysis

This study aimed to summarize and analyze the clinical and genetic characteristics of diseases caused by cystic fibrosis transmembrane conduction regulator (CFTR) gene mutations in Chinese children and to improve our understanding of cystic fibrosis (CF). We retrospectively analyzed the clinical data of 15 children with CFTR mutations who were admitted to Children’s Hospital of Chongqing Medical University from January 2012 to January 2023. 15 Chinese patients were included in our study, among which 9 had a confirmed diagnosis of CF. The median age of onset was 1.00 years (IQR 0.11–5.08 years, range 0-13.17 years). The median age of diagnosis was 5.33 years (IQR 0.43–11.33, range 0.09–14.17 years). Among those confirmed CF patients, 66.7% had bronchiectasis, 88.9% had malnutrition, and 66.7% had fatty stools. Across all hospitalizations, P. aeruginosa (6 patients), Haemophilus influenzae (6 patients), Staphylococcus aureus (5 patients), and Klebsiella pneumoniae (3 patients) were the most common bacterial infections. We identified 27 variants (two patients had three variants and one patient had single variant) from 15 individuals. The common variants included c.1521_1523delcTT (3 patients), c.2909G > A (2 patients), c.1766 + 5G > T (2 patients), and c.374T > C (2 patients). Four novel variants were found, namely c.2476_2477AACG ins, c.3104 A > G, c.884delT and c.4137-35G > A. Our study demonstrated that the clinical phenotypes associated with CFTR gene mutations are diverse. CFTR gene variants are rare in China, and the pathogenicity of over half of the associated loci remains unclear. Enhancing sweat chloride detection should be applied to facilitate the diagnosis of these conditions and clarify the pathogenicity of these variants.