[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.目的： 分析囊性纤维化跨膜传导调节因子（CFTR）基因变异患儿临床特征。 方法： 回顾性分析2013年12月至2020年10月就诊于重庆医科大学附属儿童医院经全外显子测序确定存在CFTR基因变异7例患儿的一般情况、临床表现、基因测序结果、诊断、治疗情况。 结果： 7例患儿（男2例，女5例），年龄5.2（0.5~11.3）岁，主要临床表现为营养不良5例、反复呼吸道感染4例、支气管扩张3例、脂肪泻3例、婴儿期呕吐2例、肝硬化2例、胎粪性肠梗阻1例、代谢性碱中毒及低氯血症1例。经全外显子测序和Sanger 测序验证共发现15个变异位点，其中3个为新发现变异，7个为错义变异。4例患儿确诊为囊性纤维化，3例患儿囊性纤维化诊断依据不足，更倾向于诊断CFTR基因相关性疾病（CFTR-RD）。相较于囊性纤维化患儿，CFTR-RD患儿胰腺功能不全及进行性肺功能损伤表现较轻。6例患儿经对症治疗后，症状均得到控制，1例患儿因肺部感染重、严重水盐代谢紊乱放弃出院。 结论： CFTR基因变异相关疾病的发病年龄、变异位点及临床表现多样，全外显子测序可协助诊断。部分患儿CFTR基因变异致病性质不明，诊断囊性纤维化依据不足，不可过度诊断或漏诊，需警惕CFTR-RD，从而进行长期规范化管理。.