Case Report of a Chinese Cystic Fibrosis Boy with thec.1521_1523delCTT/c.3874-4522A>G Genotypes

This report entails a case of an 11-year-old Chinese boy with cystic fibrosis (CF), who bears the c.1521_1523delCTT/c.3874-4522A>G genotype, which is extremely rare in Chinese population. Notably, the deep intron mutation c.3874-4522A>G was the first time identified among Chinese patients, which was reported mainly associated with mild phenotype. It is generally considered that a mild allele sustains CFTR function in a dominant fashion, even if paired with a severe allele. However, in the present report, the c.3874-4522A>G mutation was found related to severe pulmonary diseases, including early symptom onset, progressive bronchiectasis, recurrent airway P. aeruginosa combined with MRSA, rapid decline of lung function, and poor weight gain, which suggesting severe phenotype. Despite intensive chest care and optimized therapy, the child ultimately died of cardiopulmonary failure 3 months after discharge.