[Molecular diagnosis of two Chinese cystic fibrosis children and literature review].

OBJECTIVE: To investigate the clinical manifestations and molecular features of cystic fibrosis in Chinese children.

METHOD: A retrospective analysis of two pediatric cystic fibrosis cases diagnosed by gene test in Beijing Children's Hospital, Capital Medical University from 2010 to 2015, and Chinese cystic fibrosis reported patients searched of"cystic fibrosis, Chinese"on Chinese databases (CNKI, Wanfang Data) and PubMed from 1975 to 2015.The clinical manifestations and molecular features were analyzed.

RESULT: One of the two newly diagnosed cystic fibrosis cases was a 10-year old girl who suffered from reccurent cough with expectoration and associated with cirrhosis.Sweat tests showed increased chloride twice with the lower level of 306.82 mmol/L.The other was an 8-month old boy with reccurent pneumonia from neonate, failure to thrive and fatty diarrhea.Two children had various degrees of bronchiectasis and massive sticky secretion on the bronchoscopy.They had no family history and their parents had no consanguineous marriage.CFTR mutations of c. 595C>T and c. 2290C>T were found in gene tests.On the database, twenty-one reports involving thirty-six Chinese patients (16 males and 20 females) were retrieved.Together with this group of 2 cases, a total of 38 cases were involved.The age at diagnosis was 4 months to 28 years with a median age of 10 years.All patients had reccurent respiratory infections, twenty-seven cases (71%) had malnutrition, fifteen (39%)had chronic diarrhea, and 16 cases (42%) had other digestive manifestations, including jaundice (4 cases), hepatomegaly (11 cases), ascites (2 cases) and pancreatic atrophy (3 cases). Five cases had a positive family history and six cases had a suspicious family history.Consanguineous marriage was found in three families.Sweat test revealed elevated chloride (52-327 mmol/L) in 28 cases.Eight of the 16 patients who performed pancreatic exocrine function examination showed pancreatic insufficiency.Eighteen of the 20 patients described the image manifestation of bronchiectasis.The age at death of 13 patients(34%) was 4 months to 25 years with a median of 11 years.Twenty-nine rare CFTR mutations were found in 25 tested patients, and c. 1766+ 5G>T(5 cases), c.2083dupG and c. 2684G>A (3 cases) held the top three mutation patterns.

CONCLUSION: Respiratory symptoms and bronchiectasis are the main manifestations of Chinese cystic fibrosis patients, although some of them may be associated with malnutrition, digestive symptoms and pancreatic insufficiency. CFTR mutations are various and rare in Caucasians.