[CFTR gene variations and phenotypes in seven children].

Objective: To analyze the cystic fibrosis transmembrane conductance regulator (CFTR) gene variations and phenotypes in 7 Chinese children. Methods: In this retrospective study, the data of 7 children with CFTR gene variations admitted to Children's Hospital of Chongqing Medical University from December 2013 to October 2020 were extracted. The general information, clinical manifestations, gene variations, diagnosis and treatment were summarized. Results: Among the 7 children, 2 were males and 5 were females, aged 5.2(0.5-11.3) years. Main clinical manifestations included malnutrition (5 cases), recurrent respiratory infection (4 cases), bronchiectasis (3 cases), steatorrhea (3 cases), vomiting in infancy (2 cases), liver cirrhosis (2 cases), meconium ileus (1 case), metabolic alkalosis and hypochloremia (1 case). A total of 15 variations were found by whole exon sequencing and Sanger sequencing, among which 3 were newly discovered, and 7 were missense mutations. Four children were diagnosed as CF, and the other 3 were diagnosed as CFTR related disease (CFTR-RD). Compared with CF patients, the pancreatic insufficiency and typical CF lung disease were relatively mild in CFTR-RD patients. After treatment, 6 children were clinically improved, while the rest one withdrew treatment due to critical pulmonary infection and disturbance of water-electrolyte metabolism. Conclusions: The loci and phenotypes of CFTR gene variants vary hugely and the pathogenicity of some variations are not clear. Whole exon sequencing can facilitate the identification of CF-and CFTR-RD-causing variaions. For the cases not compatible with CF, CFTR-RD should be considered and evaluated by timely gene detection, so as to carry out appropriate long term management.