1. Department of Neurology; The Danish Headache Center; Glostrup Hospital; University of Copenhagen; Glostrup; Denmark
2. The Novo Nordisk Foundation Center for Basic Metabolic Research; Faculty of Health and Medical Sciences; University of Copenhagen; Denmark
3. Institute of Biological Psychiatry; Mental Health Center Sct. Hans; University of Copenhagen; Roskilde; Denmark
4. deCODE Genetics; Sturlugata 8 IS-101; Reykjavik; Iceland