Longitudinal Observational Study on the Course of Cystic Fibrosis Lung Disease in Patients Following Newborn Screening

Inclusion Criteria: 1. Newly diagnosed patients with Cystic Fibrosis (CF). Diagnosis of CF: at least one of the following three international accepted criteria is fulfilled: i) sweat chloride ≥ 60mEq/L and/or ii) 2 CF-causing mutations in the CFTR gene and/or iii) changes typical for CF in the transepithelial potential difference in nasal or rectal epithelium. 2. Age and mode of diagnosis: * Early diagnosed (ED): Initial diagnosis following CF-NBS or for other reasons in the first 4 months of life (in preterms corrected age of 4 months) after January 1st, 2006. Other reasons could be prenatal diagnostics, meconium ileus or positive family history. * Late diagnosed (LD): Diagnosed after the fourth month of life due to clinical symptoms; initial diagnosis after January 1st, 2006. Exclusion Criteria: All patients are excluded who themselves or whose parents do not want to participate or that withdraw from the study; or those in whom the diagnosis of CF is unsure. Further exclusion criteria are: 1. Preterms \<30th week of gestation 2. Longer period of mechanical ventilation in first 3 months of life 3. A significant medical disease or condition other than CF likely to interfere with the child's ability to complete the entire protocol 4. Previous major surgery except for meconium ileus or atresia of the intestine 5. Other major organ dysfunction, excluding pancreatic or hepatic dysfunction or another condition due to CF 6. Physical findings that would compromise the safety of the subject or the quality of the study data as determined by investigator 7. Chronic lung disease other than CF (e.g. bronchopulmonary dysplasia) 8. History of adverse reaction to medication for sedation or known claustrophobia Criteria, which lead to a displacement of the procedures in sedation until the child has recovered: - Clinically significant upper airway obstruction as determined by investigator (e.g. severe laryngomalacia, markedly enlarged tonsils, significant snoring, diagnosed obstructive sleep apnoea) \- Severe gastroesophageal reflux, defined as persistent frequent emesis despite anti-reflux therapy