Seven Cases of Williams-Beuren Syndrome: Endocrine Evaluation and Long-Term Follow-Up

Objectives:

Hypercalcemia, hypothyroidism, and early puberty are the most common endocrine disorders defined in Williams-Beuren syndrome (WBS). Here, the endocrine evaluation and long-term follow-up of seven patients with WBS are given.

Methods:

Data were obtained from patients’ medical records. WBS was diagnosed by demonstration of the deletion on chromosome 7 by using FISH method (7q11.23). Anthropometric measurements and growth velocities (GV) of patients during L-thyroxine (L-T4) treatment were evaluated. Thyroid ultrasonography was performed and thyroid volume was calculated. L-T4 was started in patients with hypothyroidism and WBS.

Results:

Six patients were male. Age at the diagnosis of WBS was 1.04 (3.47) decimal-year. Five of them were born small for gestational age. They all had mild hypercalcemia (9.9-11.1 mg/dL). Three of the patients had overt hypothyroidism, while subclinical hypothyroidism was detected in three patients [(0.66 (5.77) decimal-year]. At the diagnosis, serum thyroid-stimulating hormone was 10.5±6.3 μIU/mL and free T4 was 0.9±0.1 ng/dL. L-T4 was started at 5±3.9 μg/kg. Four patients had thyroid hypoplasia and one had thyroid agenesis. Growth hormone (GH) deficiency was determined in one patient. Height SDS was -3.26 at the age of 34/12 decimal-years when human GH was initiated and increased to -1.45 at the age of 6.08 decimal-years. The puberty onset age in two patients was normal. Follow-up duration was 5.3±2.2 years. Mean GV was 12.9±7.2 cm and 7.6±2 cm at the end of the first and second years of the therapy, respectively. At the last visit, L-T4 dose was 2.9±1 μg/kg. All patients had neurodevelopmental retardation and were receiving special education.

Conclusion:

Hypothyroidism was the most common endocrine problem in our patients (85.7%). Untreated hypothyroidism also causes mental and motor retardation particularly in infancy period in WBS. Therefore, physicians must be alert for the possible diagnosis of WBS and to investigate the thyroid morphology and function.