The major complication of hypercalcemia relates to timing of any corrective cardiac surgery. Nephrocalcinosis and sclerosis of the long bones occasionally are seen in severe cases. Systemic hypertension may occur. A baseline echocardiogram should be performed in all patients diagnosed with WS regardless of the cardiac physical exam. Approximately half of all children with WS will have a significant cardiac lesion.
Cardiovascular management is dependent on the specific cardiac lesion present.
In addition to ECGs and echocardiograms, children with SVAS may require cardiac catheterization as part of their presurgical evaluation. A renal ultrasound should also be obtained in the initial workup not only to look for anatomic abnormalities but also for nephrolithiasis due to hypercalcemia. The incidence of renal abnormalities is low in WS, but is significantly higher than the general population. Thyroid function studies should be obtained as hypothyroidism is far more common in WS than the general population, although the exact prevalence is not known. Williams syndrome is a complex multisystem medical condition that requires the attention of multiple health care professionals.