title: Thyroid dysfunction in children with Down's syndrome.
abstract: Thyroid function tests were carried out on 320 children with Down's syndrome aged between 5 d and 10 y. Thyroid function was normal in 230 patients (71.9%) and abnormal in 90 (28.1%). Six patients (1.8%) had primary congenital hypothyroidism, one patient had acquired hypothyroidism and two had transient hyperthyrotropinaemia of the newborn. Sixteen of the remaining 81 patients (25.3%) had compensated hypothyroidism with increased thyroid-stimulating hormone (TSH) levels (11-20 mU l(-1)). Their T4 levels were found to be either normal or close to the lower limit of normal. These cases were started on thyroxine therapy. Sixty-five of the 81 patients had a mild compensated hypothyroidism with mild TSH elevation (6-10 mU l(-1)). None of the patients had hyperthyroidism. The antithyroid antibodies were positive in the acquired hypothyroidism case.
  
  
  CONCLUSIONS
  The prevalence of congenital hypothyroidism was 1.8% in children with Down's syndrome while 25.3% of them had compensated hypothyroidism. It is suggested that Down's syndrome patients with normal thyroid functions and those with compensated hypothyroidism should be followed annually and every 3 mo, respectively. Besides congenital hypothyroidism cases, those with TSH levels between 11 and 20 mU l(-1) may benefit from treatment with low-dose thyroxine.
authors.affiliation: Department of Paediatrics, Cerrahpaşa Medical Faculty, University of Istanbul, Turkey. beyhantuysuz@yahoo.com
authors.forename: B
authors.initials: B
authors.lastname: Tüysüz
authors.forename: D B
authors.initials: DB
authors.lastname: Beker
mesh_terms: D002648:Child; D002675:Child, Preschool; D003409:Congenital Hypothyroidism; D004314:Down Syndrome / Q000097:blood / Q000150:complications* / Q000503:physiopathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006981:Hyperthyroxinemia / Q000151:congenital / Q000209:etiology* / Q000503:physiopathology*; D007037:Hypothyroidism / Q000209:etiology* / Q000503:physiopathology*; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D013960:Thyroid Function Tests; D013961:Thyroid Gland / Q000002:abnormalities / Q000254:growth & development / Q000503:physiopathology*; D013972:Thyrotropin / Q000097:blood
chemical_list: D013972:Thyrotropin