title: Cowden's syndrome with immunodeficiency.
abstract: BACKGROUND
  Cowden's syndrome is a rare, autosomal dominant disease caused by mutations in the phosphoinositide 3-kinase and phosphatase and tensin homolog (PTEN) gene. It is associated with hamartomatous polyposis of the gastrointestinal tract, mucocutaneous lesions and increased risk of developing certain types of cancer. In addition to increased risk of tumour development, mutations in PTEN have also been associated with autoimmunity in both mice and humans. Until now, however, an association between Cowden's syndrome and immune deficiency has been reported in a single patient only.
  
  
  RESULTS
  Two patients with Cowden's syndrome and an increased frequency of infections were investigated for possible underlying immunodeficiency. In one patient, hypogammaglobulinaemia with a functional antibody deficiency was identified, while the other patient had a persisting CD4+ T cell lymphopenia (with normal antibody production).
  
  
  CONCLUSIONS
  Our data indicate that Cowden's syndrome may be associated with both T cell and B cell immune dysfunction. We recommend that patients with Cowden's syndrome and an increased frequency of infections are investigated for associated immunodeficiency.
authors.affiliation: Department of Immunology, Leicester Royal Infirmary, Leicester, UK.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Browning
authors.affiliation: Department of Biochemistry and Immunology, Addenbrooke's Hospital, Cambridge, UK Laboratory of Lymphocyte Signalling and Development, Babraham Institute, Babraham, UK.
authors.forename: Anita
authors.initials: A
authors.lastname: Chandra
authors.affiliation: Laboratory of Lymphocyte Signalling and Development, Babraham Institute, Babraham, UK.
authors.forename: Valentina
authors.initials: V
authors.lastname: Carbonaro
authors.affiliation: Laboratory of Lymphocyte Signalling and Development, Babraham Institute, Babraham, UK.
authors.forename: Klaus
authors.initials: K
authors.lastname: Okkenhaug
authors.affiliation: Department of Genetics, Leicester Royal Infirmary, Leicester, UK.
authors.forename: Julian
authors.initials: J
authors.lastname: Barwell
mesh_terms: D002648:Child; D006223:Hamartoma Syndrome, Multiple / Q000175:diagnosis* / Q000235:genetics / Q000276:immunology; D006801:Humans; D007153:Immunologic Deficiency Syndromes / Q000175:diagnosis* / Q000235:genetics; D008297:Male; D009154:Mutation; D051059:PTEN Phosphohydrolase / Q000235:genetics
chemical_list: D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human
keywords: Cell biology; Genetics; Immunology (including allergy); Infection