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.