title: Prevalence and clinical aspects of immigrants with myasthenia gravis in northern Europe.
abstract: Multiethnic studies can provide etiological clues toward the genetic and environmental influence of a disease. The aim of this study was to determine prevalence and clinical features of myasthenia gravis (MG) in immigrants compared with native patients in 2 population-based cohorts.
  
  
  
  This cross-sectional study included 843 MG patients (375 from Norway and 468 from the Netherlands). Ethnic background was defined by questionnaires.
  
  
  
  Among the participating MG patients, 163 of 843 (19.3%) were first or second generation immigrants, mainly from Europe, Asia, and South America. No marked prevalence differences were found between immigrants and native ethnic groups. MG with muscle specific kinase antibodies and MG with thymoma were more frequent in Asian MG immigrants compared with other ethnic groups (8% vs. 0-4%; P < 0.001 and 21% vs. 6-10%; P < 0.001), respectively.
  
  
  
  Our findings indicate that Asian immigrant MG patients carry genetic factors or environmental/lifestyle factors which contribute to their specific phenotype, even after migration. Muscle Nerve 55: 819-827, 2017.
authors.affiliation: Department of Neurology, Oslo University Hospital, pb 4950, Nydalen, 0424, Oslo, Norway.|Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
authors.forename: Marion Ingeborg
authors.initials: MI
authors.lastname: Boldingh
authors.affiliation: Department of Neurology, Oslo University Hospital, pb 4950, Nydalen, 0424, Oslo, Norway.
authors.forename: Angelina
authors.initials: A
authors.lastname: Maniaol
authors.affiliation: Department of Neurology, Oslo University Hospital, pb 4950, Nydalen, 0424, Oslo, Norway.|Oslo Centre for Biostatistics and Epidemiology, Research Support Services, Oslo University Hospital, Oslo, Norway.
authors.forename: Cathrine
authors.initials: C
authors.lastname: Brunborg
authors.affiliation: Department of Neurology, Leiden University Medical Centre, The Netherlands.
authors.forename: Luuk
authors.initials: L
authors.lastname: Dekker
authors.affiliation: Department of Neurology, Leiden University Medical Centre, The Netherlands.
authors.forename: Alexander
authors.initials: A
authors.lastname: Lipka
authors.affiliation: Department of Neurology, Leiden University Medical Centre, The Netherlands.
authors.forename: Erik Harmen
authors.initials: EH
authors.lastname: Niks
authors.affiliation: Department of Neurology, Leiden University Medical Centre, The Netherlands.
authors.forename: Jan
authors.initials: J
authors.lastname: Verschuuren
authors.affiliation: Department of Neurology, Oslo University Hospital, pb 4950, Nydalen, 0424, Oslo, Norway.|Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
authors.forename: Chantal
authors.initials: C
authors.lastname: Tallaksen
mesh_terms: D000328:Adult; D017668:Age of Onset; D000368:Aged; D018672:Community Health Planning; D003430:Cross-Sectional Studies; D054242:Emigrants and Immigrants / Q000706:statistics & numerical data*; D005006:Ethnicity; D005060:Europe / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009157:Myasthenia Gravis / Q000453:epidemiology* / Q000208:ethnology / Q000628:therapy; D015995:Prevalence; D020794:Receptor Protein-Tyrosine Kinases / Q000276:immunology; D011950:Receptors, Cholinergic / Q000276:immunology; D013934:Thymectomy; D013945:Thymoma / Q000453:epidemiology / Q000601:surgery; D055815:Young Adult
chemical_list: D011950:Receptors, Cholinergic; C095714:MUSK protein, human; D020794:Receptor Protein-Tyrosine Kinases
keywords: clinical features; epidemiology; ethnicity; immigrants; myasthenia gravis; thymoma