Studies on thyroid and hypophysary thyrotrophic hormone (TSH) in Down syndrome.

Serum TSH was studied in 22 patients with Down syndrome, from 4 to 15 years old. In 6 of these patients radioidine uptake by thyroid gland after 2 and 24 hours of administration and clearance rates before and after TSH stimulus (10 mul-IM) were measured. Results show that serum TSH was normal in 17 patients and above normal limits in 5 patients. Thyroid uptake after 2 hours as well clearance rates, both below normal, had a response to TSH stimulus with normal or below values. These data along with previous reports, suggest, that in children with Down syndrome, there is a thyroid dysfunction in which a slow response no TSH stimulus seems to be the basic defect.