INTRODUCTION
Cystic fibrosis (CF) is a serious and life-shortening autosomal recessive disorder, affecting approximately 100,000 persons worldwide, and characterized by defective chloride transport channel in epithelial cells of exocrine tissues[1]. The progression of the disease may result in multi-system dysfunction, including sinopulmonary disease, meconium ileus, pancreatic insufficiency and sweat electrolyte abnormalities. To date, approximately 2000 mutations in the CFTR gene have been reported worldwide[2]. The epidemiology of CF is well studied in Caucasians from developed countries, however, the data on the incidence of CF in China mainly come from studies with small sample size or case reports over the past 4 decades. Up to now, only approximately 110 CF patients of Chinese origin were reported in literature[3]. In this report, we present a pediatric case with severe CF phenotype and c.1521_1523delCTT/c.3874-4522A>G genotype, which is extremely rare in Chinese population.