Thyroid dysfunction in children with Down's syndrome

Acta Paediatr. 2001 Dec;90(12):1389-93. doi: 10.1080/08035250152708770.


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.

Conclusion: 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.

MeSH terms

  • Child
  • Child, Preschool
  • Congenital Hypothyroidism
  • Down Syndrome / blood
  • Down Syndrome / complications*
  • Down Syndrome / physiopathology
  • Female
  • Follow-Up Studies
  • Humans
  • Hyperthyroxinemia / congenital
  • Hyperthyroxinemia / etiology*
  • Hyperthyroxinemia / physiopathology*
  • Hypothyroidism / etiology*
  • Hypothyroidism / physiopathology*
  • Infant
  • Infant, Newborn
  • Male
  • Thyroid Function Tests
  • Thyroid Gland / abnormalities
  • Thyroid Gland / growth & development
  • Thyroid Gland / physiopathology*
  • Thyrotropin / blood


  • Thyrotropin