title: High risk of MS in Iranian immigrants in Gothenburg, Sweden.
abstract: BACKGROUND
  In this study we investigated the risk of multiple sclerosis (MS) in migrants who had moved from Iran to Gothenburg, Sweden.
  
  
  METHODS
  Patients born in Iran were retrieved from a population-based cohort, which included 534 MS and clinically isolated syndrome patients, born 1959-1990, aged 10-39 years at disease onset in Gothenburg. The expected versus observed number of migrants from Iran was calculated.
  
  
  RESULTS
  The MS risk in the Iranian migrants in Gothenburg was several times higher than in Isfahan, Iran (hazard ratio 3.88, 95% confidence interval 2.17-6.40). Compared with the general population of Gothenburg, the observed number of 17 Iranian patients was higher than the expected value of 9.89 (hazard ratio 1.72, 95% confidence interval 1.00-2.75).
  
  
  CONCLUSIONS
  Migration from a medium-risk to a high-risk area may increase the MS risk to that of the high-risk area.
authors.affiliation: Institute of Neuroscience and Physiology, Sahlgrenska University Hospital, Gothenburg, Sweden. cecilia.ahlgren@neuro.gu.se
authors.forename: C
authors.initials: C
authors.lastname: Ahlgren
authors.forename: J
authors.initials: J
authors.lastname: Lycke
authors.forename: A
authors.initials: A
authors.lastname: Odén
authors.forename: O
authors.initials: O
authors.lastname: Andersen
mesh_terms: D000293:Adolescent; D000328:Adult; D044466:Asian People / Q000706:statistics & numerical data*; D054242:Emigrants and Immigrants / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007492:Iran / Q000208:ethnology; D008279:Magnetic Resonance Imaging; D008297:Male; D009103:Multiple Sclerosis / Q000175:diagnosis / Q000208:ethnology*; D018570:Risk Assessment; D012307:Risk Factors; D013548:Sweden / Q000453:epidemiology; D055815:Young Adult