Abstract
Williams syndrome is an autosomal-dominant multisystem disorder. Infantile hypercalcemia has been documented in 15% of infants with Williams syndrome, and is commonly transient and mild. The need for pamidronate therapy has been reported in a few cases of Williams syndrome with severe hypercalcemia. Few cases of acute kidney injury due to severe hypercalcemia during Williams syndrome have also been recorded. We report the case of an infant with Williams syndrome who presented with acute kidney injury and severe hypercalcemia and was treated with intravenous pamidronate. In addition, we aimed to consider management strategies that maintain renal function and promote growth until adulthood.