1. Department of Pediatrics Institute of Clinical Sciences Sahlgrenska Academy The Queen Silvia Children's Hospital Gothenburg University Gothenburg Sweden
2. Department of Internal Medicine Sahlgrenska University Hospital Gothenburg Sweden
3. Division of Endocrinology and Metabolism Department of Internal Medicine Medical University of Graz Graz Austria
4. Department of Clinical Chemistry Department of Clinical and Experimental Medicine Linköping University Linköping Sweden