title: Endocrine autoimmunity in Turner syndrome.
abstract: BACKGROUND
  Turner syndrome is caused by numeric and structural abnormalities of the X chromosome. An increased frequency of autoimmunity as well as an elevated incidence of autoantibodies was observed in Turner patients. The aim of this study was to conduct a retrospective analysis of the incidence of autoimmunity in 66 Italian patients affected by Turner syndrome.
  
  
  METHODS
  Sixty-six unselected and consecutive Italian Turner patients were recruited. The association between age, karyotype and the presence of clinical/pre-clinical autoimmune disorders and of autoantibodies was examined.
  
  
  RESULTS
  Out of the 66 Turner patients, 26 had thyroid autoimmune disorders (39.4%), 14 patients had Hashimoto's thyroiditis with clinical or subclinical hypothyroidism (21.2%) and 12 patients had circulating anti-thyroid antibodies, echographic pattern of diffuse hypoechogenicity and normal thyroid hormone levels (18.2%). None were affected by Graves' disease. We analyzed the overall incidence of thyroid autoimmunity within the 3 different age groups 0-9.9, 10-19.9 and 20-29.9 years. No statistically significant difference was observed in the incidence of thyroid autoimmunity within the age-groups (χ2-test p > 0.05).Out of the 66 patients, 31 patients had the 45,X karyotype; within this first group 14 out of 31 patients were affected by autoimmune thyroid disease. A second group of 29 patients included 19 patients with mosaicism, 5 patients with deletions and 5 patients with ring chromosome; out of these 29 patients 7 were affected by autoimmune thyroid disease. A third group included 6 patients with X isochromosome; 5 out of 6 were affected by autoimmune thyroid disease. A statistically significant difference in the frequency of thyroid autoimmunity within the different karyotype groups was observed (χ2-test p = 0.0173).When comparing the X isochromosome group with the pooled group of other karyotypes, of note, the frequency of thyroid autoimmunity was statistically higher in the X isochromosome group (Fisher exact test p = 0.0315).
  
  
  CONCLUSIONS
  Our data confirm a high frequency of thyroid autoimmunity in Italian Turner patients. Patients with X isochromosome are more prone to develop thyroid autoimmunity. Further, an early assay of autoantibodies and monitoring thyroid hormones is fundamental for detecting hypothyroidism earlier and start adequate replacement therapy.
authors.forename: Armando
authors.initials: A
authors.lastname: Grossi
authors.forename: Antonino
authors.initials: A
authors.lastname: Crinò
authors.forename: Rosa
authors.initials: R
authors.lastname: Luciano
authors.forename: Antonietta
authors.initials: A
authors.lastname: Lombardo
authors.forename: Marco
authors.initials: M
authors.lastname: Cappa
authors.affiliation: Autoimmunity Laboratory, Immunology Area, Bambino Gesù Children's Hospital IRCCS, Piazza S, Onofrio, 4-00165 Rome, Italy. alessandra.fierabracci@opbg.net.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Fierabracci
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D001323:Autoantibodies / Q000032:analysis / Q000276:immunology*; D001327:Autoimmune Diseases / Q000175:diagnosis / Q000453:epidemiology / Q000276:immunology; D015551:Autoimmunity / Q000276:immunology* / Q000502:physiology; D002648:Child; D002675:Child, Preschool; D016208:Databases, Factual; D005260:Female; D005500:Follow-Up Studies; D050031:Hashimoto Disease / Q000175:diagnosis / Q000453:epidemiology / Q000276:immunology; D006801:Humans; D015994:Incidence; D007223:Infant; D007558:Italy; D008297:Male; D012189:Retrospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D017678:Sex Distribution; D013963:Thyroid Hormones / Q000276:immunology* / Q000378:metabolism; D013967:Thyroiditis, Autoimmune / Q000175:diagnosis / Q000453:epidemiology / Q000276:immunology*; D014424:Turner Syndrome / Q000175:diagnosis / Q000453:epidemiology / Q000276:immunology*; D055815:Young Adult
chemical_list: D001323:Autoantibodies; D013963:Thyroid Hormones