Thyroid anomalies in Williams syndrome: investigation of 95 patients.

Thyroid involvement in Williams syndrome (WS) was recently reported in two small groups of patients, both showing an increased prevalence of elevation of TSH serum concentration; in one of the two reports, 70% of the patients demonstrated a hypoplasia of thyroid gland as well. In our institution, we currently follow a large population of WS patients who periodically undergo a multispecialist clinical evaluation that includes ultrasound evaluation of the thyroid gland, and levels of FT3, FT4, TSH, and anti-thyroid antibodies. Here, we report on the prevalence of thyroid structural and functional anomalies, in a population of 95 WS patients, half of them followed for more than 5 years. Our study confirms the increased incidence of both elevated TSH serum values (37.9% in our sample) and thyroid gland hypoplasia (74.7%). Moreover, we demonstrated that TSH elevation declines with age. For this reason, we suggest that a complete thyroid evaluation be performed in every patient with WS, and that this medical complication should be periodically searched for in follow-up visits.