Endocrine Abstracts

Introduction: Hypercalcaemia in Williams-Beuren syndrome (WBS) is usually mild and transient, but may be severe in about 5% of new presentations. Often some children will not respond well to traditional therapies.

Case report: We describe three cases of acute hypercalcaemia and their management in a regional Paediatric unit. Case 1: A 16-month-old known WBS girl, presented with irritability, reduced feeding. Corrected serum calcium was 4.51 mmol/l. She was managed acutely with intravenous fluids and frusemide. Serial blood chemistry showed a downward trend of the serum total and ionised calcium. Oral prednisolone was started at 1 mg/kg per day, and gradually tapered over 4 months. Case 2: A 9-month-old girl admitted for investigation of failure to thrive. Corrected serum calcium was 3.78 mmol/l. She was acutely managed with intravenous fluids and furosemide. 1 mg/kg per day oral prednisolone initiated and tapered over 2 months. She presented twice in the following 10 months with symptomatic hypercalcaemia (>4 mmol/l). She received 1 dose of intravenous pamidronate (1 mg/kg) during one presentation and this was effective and safe. Case 3: A 13-month-old girl presented with failure to thrive, withcorrected serum calcium 3.99 mmol/l. She received the traditional therapies initially, which were ineffective. Intravenous pamidronate at 1 mg/kg was given due to recalcitrant hypercalcaemia. Furosemide and prednisolone were discontinued following sustained normocalcaemia. Cases 2 and 3 were diagnosed WBS following their presentations. All cases demonstrated bilateral medullary nephrocalcinosis. They were managed on a low calcium diet.

Conclusion: Treatment of hypercalcaemia in WBS is achieved traditionally with intravenous fluids, loop diuretics, steroids, and a low calcium diet. In this case series, 2/3 cases required bisphosphonate therapy to effectively restore normocalcaemia. Bisphosphonates are now used more commonly in Paediatric Endocrinology and are found to be safe and effective in this case series.

Keywords: Williams-Beuren syndrome, bisphosphonate, hypercalcaemia