Clinical Phenotypes and Genotypic Spectrum of Cystic Fibrosis in Chinese Children.

OBJECTIVES: To characterize the clinical phenotypes and genotypic spectrum of cystic fibrosis (CF) in Chinese children. STUDY DESIGN: We recruited and characterized the phenotypes of 21 Chinese children with CF. All 27 exons and their flanking sequences of the CF transmembrane conductance regulator gene were amplified and sequenced to define the genotypes. RESULTS: Bronchiectasis (95.2%) and sinusitis (76.2%) were the most common clinical presentations among our patients. By contrast, pancreatic insufficiency was rare (14.3%). The predominant organism found in the airways was Pseudomonas aeruginosa (66.7%). There were obvious reductions of forced expiratory volume in the first second (mean ± SD: 71.8% ± 17.2% predicted) and forced expiratory flows at 75% of exhaled vital capacity (33.7% ± 20.4% predicted) in children with CF. Overall, we identified 22 different mutations, including 12 missense, 5 nonsense, 2 frameshift, 1 in-frame insertion, 1 splice site, and 1 3'untranslated region mutation. Of these, 7 were novel observations (W216X[780G→A], 1092insA, Q359X, D567Y, 2623-126T→C, 3439delA and 4575+110C→G), and the most common types were L88X and I556V. One de novo mutation (1092insA) was also revealed. Except for N1303K and R334W, none of them were present in the common Caucasian CF transmembrane conductance regulator mutation-screening panels. CONCLUSIONS: There was a 5.7-year delay between the first clinical presentation and the eventual CF diagnosis, suggesting that CF may be underdiagnosed in China. The clinical phenotypes and genotypic spectrum are different from that observed in Caucasians.

Bronchiectasis in a diverse US population: effects of ethnicity on etiology and sputum culture.

BACKGROUND: Previous studies of patients with bronchiectasis have found that the cause is idiopathic in the majority of cases, but these studies were done in homogeneous populations. We hypothesized that the etiology of bronchiectasis can be determined in a higher percentage of patients in a diverse US population and will differ significantly based on ethnicity. METHODS: One hundred twelve patients with bronchiectasis confirmed by chest CT scan entered the study. Data from 106 patients were available for full evaluation. Clinical questionnaire, pulmonary function tests, sputum microbiology, laboratory data, and immune function testing were done. Results were analyzed by ethnicity and etiology. RESULTS: Patients were 61.6% European American (EA), 26.8% African American (AA), 8.9% Hispanic American (HA), and 2.7% Asian American. A cause of bronchiectasis was determined in 93.3% of patients. In 63.2% of patients, bronchiectasis was caused by immune dysregulation, including deficiency (n = 18 [17%]), autoimmune disease (n = 33 [31.1%]), hematologic malignancy (n = 15 [14.2%]), and allergic bronchopulmonary aspergillosis (n = 1 [0.9%]). Rheumatoid arthritis was the cause of bronchiectasis in 28.6% of AA patients vs 6.2% of EA patients (P < .05). Hematologic malignancy was the etiology in 20.0% of the EA patients vs none of the AA patients (P = .02). A significantly higher percentage of HA patients had Pseudomonas aeruginosa in their sputum compared with AA and EA patients (P = .01). CONCLUSIONS: The etiology of bronchiectasis can be determined in the majority of patients in a heterogeneous US population and is most often due to immune dysregulation. Rheumatoid arthritis is more likely in AA patients than EA patients. HA patients are more likely to have P aeruginosa in their sputum.