Williams syndrome with severe hypercalcaemia

We present an 11-month-old girl child with complaints of constipation, cough, fever, vomiting and growth retardation. On examination, she had facial dysmorphism, hypertension and murmur. The genetic evaluation showed 7q microdeletion specific to Williams syndrome. Abdominal imaging was suggestive of nephrocalcinosis which is rare for this age group. The baby was managed symptomatically and specific treatment like pamidronate, calcitonin and steroid therapy were also administered to reduce hypercalcaemia. Severe hypercalcaemia with associated hypertension and nephrocalcinosis is very rare. Hence, we emphasise here the importance of early detection of these features and their appropriate management for a better outcome of the patient.