1. Department of Paediatrics; Rigshospitalet; University of Copenhagen; Copenhagen Denmark
2. Department of Neurology; The Danish Multiple Sclerosis Registry; Rigshospitalet; University of Copenhagen; Copenhagen Denmark
3. Department of Clinical Epidemiology; University of Aarhus; Clinical Institute; Aarhus Denmark
4. National Institute of Public Health; University of Southern Denmark; Copenhagen Denmark
5. Department of Neurology; Danish Multiple Sclerosis Center; Rigshospitalet; University of Copenhagen; Copenhagen Denmark