1. Department of Obstetrics and Prenatal Medicine; University of Bonn; Bonn Germany
2. Department of Human Genetics; Radboud University Medical Center; Nijmegen The Netherlands
3. Center for Assisted Reproduction and Prenatal Diagnosis; Minden Germany
4. Medical Office for Human Genetics; Wiesbaden Germany
5. Department of Neonatology and Pediatric Intensive Care; University of Bonn; Bonn Germany
6. Institute of Human Genetics; University of Bonn; Bonn Germany