“…The subject of acute porphyrias has been addressed previously in Tidsskriftet (7,8), but as with many other rare diseases, there are few systematic studies based on large cohorts. The aim of this study was to use information about people with porphyrias registered with the Norwegian Porphyria Centre (NAPOS) and data from the Norwegian Porphyria Registry to provide an overview of porphyrias in Norway, focusing on incidence, prevalence, time from onset of symptoms to diagnosis, follow-up routines and quality of life.…”