1. Faculty of Medicine, Institute of Gynecology, Obstetrics, and Pediatrics, University of Copenhagen, Copenhagen, Denmark;
2. Department of Pediatrics and
3. The Cytogenetic Laboratory, The University Hospital Rigshospitalet, Copenhagen, Denmark;
4. Department of Pediatrics, The University Hospital Linkjöping, Stockholm, Sweden;
5. Department of Pediatrics, The University Hospital Umeå, Stockholm, Sweden;
6. Department of Pediatrics, Aarhus University Hospital, Skejby, Denmark;
7. Department of Pediatrics, Astrid Lindgrens Barnsjukhus, Stockholm, Sweden;
8. Department of Pediatrics, University Hospital, Reykjavik, Iceland;
9. Department of Pediatrics, University Hospital, Trondheim, Norway;
10. Department of Biostatistics, University of Copenhagen, Copenhagen, Denmark;
11. Department of Pediatrics, University Hospital, Helsinki, Finland; and
12. Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, MN