title: Familial aggregation of IgAD and autoimmunity.
abstract: BACKGROUND
  The prevalence of autoimmunity is thought to be increased among IgA deficient (IgAD) individuals. However, it is currently unclear if the two conditions coincide within families.
  
  
  OBJECTIVE
  To evaluate the prevalence of autoimmunity among IgAD individuals and their 1 degrees relatives.
  
  
  METHODS
  A total of 43 IgAD individuals (32 adults and 11 children) and all available 1 degrees relatives were evaluated by a physician. A family history of autoimmunity was obtained, together with physical examination and a structured questionnaire that focused on symptoms and signs suggestive of autoimmunity.
  
  
  RESULTS
  Eight of the 32 (25%) adult IgAD, were found to have definite autoimmunity, with organ specific- and systemic autoimmune diseases equally distributed. None of the IgAD children had autoimmunity. Among the 1 degrees relatives, 27/269 (10%) had autoimmunity, compared to an estimate of 5% in the general population (p<0.05).
  
  
  CONCLUSIONS
  Autoimmune diseases are highly prevalent in individuals with IgAD and more common in their 1 degrees relatives than expected, thus, suggesting a possible common genetic component.
authors.affiliation: Department of Medicine, University of Iceland, Reykjavík, Iceland.
authors.forename: Gudmundur H
authors.initials: GH
authors.lastname: Jorgensen
authors.forename: Ingunn
authors.initials: I
authors.lastname: Thorsteinsdottir
authors.forename: Sveinn
authors.initials: S
authors.lastname: Gudmundsson
authors.forename: Lennart
authors.initials: L
authors.lastname: Hammarstrom
authors.forename: Bjorn R
authors.initials: BR
authors.lastname: Ludviksson
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000368:Aged; D015551:Autoimmunity / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D017098:IgA Deficiency / Q000235:genetics*; D007070:Immunoglobulin A / Q000235:genetics* / Q000276:immunology; D008297:Male; D008875:Middle Aged; D010375:Pedigree; D011795:Surveys and Questionnaires
chemical_list: D007070:Immunoglobulin A