Thyroid function in patients with Down syndrome: preliminary results from non-institutionalized patients in the Veneto region.

We investigated thyroid function of 108 home-reared Down syndrome (DS) patients. Five had overt hypothyroidism, 2 were hyperthyroid, and 33 had high TSH values with an exaggerated response to TRH test despite hormone levels in the normal range. This finding indicated subclinical hypothyroidism. Antithyroid antibodies (antimicrosome and antithyroglobulin) were present in 13 patients. At the same time we investigated 73 parents: only one mother was hypothyroid and antithyroid autoantibodies were found in only 8% of Down syndrome parents.