title: Familial occurrence of microscopic colitis: a report on five families.
abstract: BACKGROUND
  The etiology and pathogenesis of microscopic colitis is unknown. Whether genetic predisposition is of importance, as in many other gastrointestinal diseases, is unknown. Familial occurrence of collagenous colitis has earlier been reported only in two families.
  
  
  METHODS
  Familial occurrence of microscopic colitis was searched for in a Swedish national microscopic colitis register.
  
  
  RESULTS
  Familial occurrence of microscopic colitis was identified in five families. In all families a sister-sister relationship was found. Two sisters with collagenous colitis had been living apart in different Nordic countries for many years before developing the disease. In one pair, the smoking sister had collagenous colitis and the never smoking sister had lymphocytic colitis.
  
  
  CONCLUSIONS
  Considering the relative rarity of microscopic colitis, these findings indicate that a genetic predisposition may be of importance.
authors.affiliation: Dept. of Medicine, Orebro Medical Centre Hospital, Sweden.
authors.forename: G
authors.initials: G
authors.lastname: Järnerot
authors.forename: E
authors.initials: E
authors.lastname: Hertervig
authors.forename: C
authors.initials: C
authors.lastname: Grännö
authors.forename: E
authors.initials: E
authors.lastname: Thorhallsson
authors.forename: S
authors.initials: S
authors.lastname: Eriksson
authors.forename: C
authors.initials: C
authors.lastname: Tysk
authors.forename: I
authors.initials: I
authors.lastname: Hansson
authors.forename: H
authors.initials: H
authors.lastname: Björknäs
authors.forename: J
authors.initials: J
authors.lastname: Bohr
authors.forename: M
authors.initials: M
authors.lastname: Olesen
authors.forename: R
authors.initials: R
authors.lastname: Willén
authors.forename: I
authors.initials: I
authors.lastname: Kagevi
authors.forename: A
authors.initials: A
authors.lastname: Danielsson
mesh_terms: D000328:Adult; D000368:Aged; D003092:Colitis / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008875:Middle Aged; D012042:Registries / Q000706:statistics & numerical data; D012907:Smoking / Q000453:epidemiology; D013548:Sweden