Death following tonsillectomy in a child with Williams syndrome.

Williams syndrome (WS) is an uncommon genetic syndrome due to a deletion of several genes on chromosome 7. The syndrome is associated with dysmorphic facies, neurological manifestations, idiopathic hypercalcemia, and cardiac abnormalities, particularly supravalvular aortic stenosis (SVAS). Children with Williams syndrome may have chronic serous otitis media and/or obstructive sleep apnea. Hyperacusis is also commonly seen in these children. We report a case of sudden death at the time of tonsillectomy/adenoidectomy and bilateral tympanostomy tube placement in a child with Williams syndrome. All children with Williams syndrome should have a thorough cardiac evaluation before undergoing general anesthesia for any otolaryngologic procedure.