ESPE Abstracts

Background: Thyroid disorders (subclinical hypothyroidism and structural abnormalities) are common in Williams syndrome (WS) patients.

Objective and hypotheses: Central hypothyroidism and GH deficiency (GHD) in a WS patient are discussed.

Method: Case report and literature review.

Results: A 5-month-old male was admitted to our hospital because of growth failure since the 3rd month, mild dysmorphisms, micropenis. He was a second-born at term from non-consanguineous parents. During pregnancy the mother has been treated with levothyroxine for a Hashimoto’s thyroiditis. After birth, the baby presented normal adaptation parameters, weight 2880 g (3rd–10th), length 48 cm (3rd–10th), and head circumference 33 cm (3rd–10th); later mild jaundice, without history of hypoglycaemia or calcium disorders was reported. No thyroid dysfunction was detected by screening test. At admission, weight was 5670 g (<3rd), length 63 cm (3rd), and head circumference 40 cm (<3rd); no neurological abnormalities or heart murmurs were noted. Main signs observed at the dysmorphological evaluation were: fullness of the peri-orbital structures, epicanthal folds, full cheeks, small upturned nose with long philtrum and down-turned corners of the mouth, micropenis. Blood tests revealed a central hypothyroidism (FT₄ 0.72 ng/dl and TSH 3.53 mcIU/ml) associated to a GHD documented by two stimulation tests (peak of GH: 1.89 and 1.76 ng/ml), IGF1 6.8 ng/ml. Remaining pituitary gland function and structure (MRI) was normal. Echocardiogram resulted unremarkable. Levothyroxine was started (upto 2 μg/kg per day) with a prompt normalization of FT₄. hGH therapy was also initiated at a dose of 0.15 mg/kg per week with a growth improvement. Genetic tests (FISH) revealed a 7q11.23 microdeletion, confirming the suspected diagnosis of WS. Array-CGH is now ongoing to define the extension of the deletion and to understand if the involvement of other genomic regions, contiguous to the WS critical region or not, can contribute to this endocrinological picture.

Conclusion: In addition to the peripheral forms, also a central hypothyroidism can be found in WS patients. Our patient also showed a GHD, that is rarely reported in WS.