title: The risk of celiac disease in 107 families with at least two affected siblings.
abstract: OBJECTIVE
  Screening for celiac disease (CD) in the apparently healthy members of 107 nuclear families with two affected siblings (sib pair) and estimating the risk of CD in siblings and parents.
  
  
  METHODS
  One hundred seven families from Sweden and southern Norway with at least two affected children were investigated. Frozen sera from 187 of the 192 healthy parents and from 94 of 95 siblings without diagnosed CD were examined for total immunoglobulin A (IgA) and anti-endomysial antibodies (EMA). Individuals with positive antibody titers underwent small intestinal biopsy.
  
  
  RESULTS
  Positive test for EMA was found in 6 of 94 (6.3%) siblings without previously diagnosed CD and in 8 of 189 (4.2%) parents. CD was confirmed by small intestinal biopsy in all siblings and seven parents. The estimated risk for CD in multiply affected families was 26.3% for siblings and 12.9% for parents. An unexpected male preponderance was found among the new CD cases (10 males, 3 females).
  
  
  CONCLUSIONS
  The risk of CD in the members of nuclear families with two affected children is approximately three times higher than that when only one child is affected. The high male preponderance of new cases is unexpected and could not be explained fully by more silent disease in males as compared with females. Considering the high level of knowledge about CD in these families, the number of undiagnosed cases is surprisingly high. The authors suggest that serologic screening should be offered to all first-degree relatives of patients with CD.
authors.affiliation: Department of Pediatrics, The Queen Silvia Children's Hospital, Göteborg University, Göteborg, Sweden. audur.gudjonsdottir@vgregion.se
authors.forename: Audur H
authors.initials: AH
authors.lastname: Gudjónsdóttir
authors.forename: Staffan
authors.initials: S
authors.lastname: Nilsson
authors.forename: Johan
authors.initials: J
authors.lastname: Ek
authors.forename: Bengt
authors.initials: B
authors.lastname: Kristiansson
authors.forename: Henry
authors.initials: H
authors.lastname: Ascher
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001323:Autoantibodies / Q000032:analysis* / Q000097:blood; D015415:Biomarkers / Q000097:blood; D002446:Celiac Disease / Q000097:blood / Q000453:epidemiology / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D009664:Norway / Q000453:epidemiology; D010375:Pedigree; D015995:Prevalence; D018570:Risk Assessment; D012307:Risk Factors; D012737:Sex Factors; D013548:Sweden / Q000453:epidemiology
chemical_list: D001323:Autoantibodies; D015415:Biomarkers