title: Peculiarities of presentation and evolution over time of Hashimoto's thyroiditis in children and adolescents with Down's syndrome.
abstract: BACKGROUND
  Studies concerning presentation and evolution over time of Hashimoto's thyroiditis (HT) in children with Down's syndrome (DS) are few, are based on limited study populations and do not include control HT groups without DS. The aim of this multicenter study was to shed further light on the relationships between DS and HT in childhood.
  
  
  METHODS
  In this retrospective study we compared thyroid function patterns at HT presentation in 2 groups of children with (group A) or without DS (group B), including 146 and 553 cases, respectively. All group A patients were subsequently re-examined after a median interval of 5.1 years in order to prospectively re-evaluate the evolution over time of thyroid function patterns in DS.
  
  
  RESULTS
  In group A, female predominance, age at HT diagnosis and rates of familiarity for thyroid diseases were significantly lower than in group B, whilst the association with non-thyroidal autoimmune diseases was more frequent. The hormonal patterns that were most frequently found in the 2 groups were, respectively, subclinical hypothyroidism (in group A) and euthyroidism (in group B). Thyroid dysfunctions were, overall, more frequent in group A (86.3 vs 45.7%, p<0.001). At re-evaluation, DS children exhibited further deterioration of thyroid function with some cases switching towards Graves' disease (GD).
  
  
  CONCLUSIONS
  HT in DS children: a) presents earlier, is not associated with female predominance and is more frequently associated with other autoimmune diseases; b) presents only very infrequently with a euthyroid hormonal profile; c) in a limited rate of cases switches with time to GD.
authors.affiliation: Department of Pediatrics, University of Messina, Messina, Italy.
authors.forename: Tommaso
authors.initials: T
authors.lastname: Aversa
authors.affiliation: Department of Pediatrics, University "Federico II", Naples, Italy.
authors.forename: Mariacarolina
authors.initials: M
authors.lastname: Salerno
authors.affiliation: Department of Paediatrics, Regional Hospital, Bolzano, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Radetti
authors.affiliation: Department of Biomedical Sciences and Human Oncology, Pediatrics Unit, University of Bari "A. Moro", Bari, Italy.
authors.forename: Maria Felicia
authors.initials: MF
authors.lastname: Faienza
authors.affiliation: Department of Pediatrics, University of Modena and Reggio Emilia, Modena, Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Iughetti
authors.affiliation: Department of Pediatrics, University of Turin, Regina Margherita Children's Hospital, Turin, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Corrias
authors.affiliation: Department of Pediatrics, University of Modena and Reggio Emilia, Modena, Italy.
authors.forename: Barbara
authors.initials: B
authors.lastname: Predieri
authors.affiliation: Department of Pediatrics, University of Turin, Regina Margherita Children's Hospital, Turin, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Mussa
authors.affiliation: Department of Pediatrics, University of Messina, Messina, Italy.
authors.forename: Silvestro
authors.initials: S
authors.lastname: Mirabelli
authors.affiliation: Department of Pediatrics, University of Messina, Messina, Italy.
authors.forename: Filippo
authors.initials: F
authors.lastname: De Luca
authors.affiliation: Department of Pediatrics, University of Messina, Messina, Italy.
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Wasniewska
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D015897:Comorbidity; D018450:Disease Progression; D004314:Down Syndrome / Q000097:blood* / Q000453:epidemiology*; D005260:Female; D050031:Hashimoto Disease / Q000097:blood* / Q000453:epidemiology*; D006801:Humans; D007223:Infant; D008297:Male; D012189:Retrospective Studies; D012737:Sex Factors