1. Department of Medical Genetics, Oslo University Hospital, Oslo, Norway
2. Institute of Clinical Medicine, University of Oslo, Oslo, Norway
3. Department of Gastroenterology, Telemark Hospital Trust, Skien, Norway
4. Oslo Centre for Biostatistics and Epidemiology, Department of Biostatistics, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
5. Department of Gynaecology and Obstetrics, Sørlandet Hospital HF Arendal, Arendal, Norway