Conflict of interest: C.S. Thornton reports grants from Insmed Medical, Trudell Medical and CHEST Foundation, outside the submitted work. H. Hebestreit reports grants from the Bavarian State Ministry of Science and the Arts (BASE-Netz (Network of the Bavarian Working Group on Rare Diseases), Bavarian Genomes), Federal Ministry of Education and Research (Collaboration on Rare Diseases within the German Medical Informatics Initiative), Vertex Pharmaceuticals, and the Innovation fund of the Federal Joint Committee (Dual Guidance Structure for Evaluation of Patients With Unclear Diagnosis in Centers for Rare Diseases (ZSE-DUO)), lecture honoraria from Springer Verlag, Takeda Pharma GmbH and Chiesi GmbH, travel support from European Cystic Fibrosis Society and the University of Edinburgh, and leadership roles with the German Society of Paediatrics, German Working Group of Centres for Rare Diseases and the European Reference Network for Rare Respiratory Diseases (ERN-LUNG), outside the submitted work.