1. Department of Congenital Heart Disease and Paediatric Cardiology, University Hospital of Schleswig-Holstein , Arnold-Heller-Str. 3, D-24105 Kiel , Germany
2. German Centre for Cardiovascular Research (DZHK) , Partner Site Kiel , Germany
3. Competence Network for Congenital Heart Defects , Berlin , Germany
4. Department for Medical Genetics, University of Oldenburg , Oldenburg , Germany