title: Multiple sclerosis: nature or nurture.
authors.forename: E S
authors.initials: ES
authors.lastname: Williams
authors.forename: R O
authors.initials: RO
authors.lastname: McKeran
mesh_terms: D005843:Geography; D006801:Humans; D009103:Multiple Sclerosis / Q000453:epidemiology*; D015995:Prevalence; D006113:United Kingdom / Q000453:epidemiology