Williams Syndrome Presenting with Recurrent and Persistent Vomiting: A Case Report

Introduction Williams-Beuren syndrome (WS) is a rare genetic condition caused by a microdeletion on chromosome 7q11.23. Gastrointestinal symptoms are relatively common in WS, but recurrent, intractable, or cyclic vomiting as an initial or dominant presenting feature is uncommon and can significantly delay diagnosis. Case Presentation We describe an 11-month-old male infant who presented to the emergency department with persistent vomiting and signs of dehydration. The child had been admitted to the hospital three times over the preceding two months for identical complaints, with vomiting recurring shortly after each discharge. On examination, he displayed the classic dysmorphic facial features of Williams syndrome, including a broad forehead, periorbital fullness, stellate iris pattern, wide mouth, and full lips. A grade 3/6 systolic murmur was audible. Laboratory evaluation revealed severe hypercalcemia (serum calcium 14.2 mg/dL). Echocardiography confirmed supravalvular aortic stenosis with the typical “hourglass” appearance. Initial management of the hypercalcemia with intravenous fluids, furosemide, and corticosteroids proved largely ineffective. Introduction of cinacalcet, a calcimimetic agent, resulted in a rapid and sustained normalization of serum calcium levels. The clinical diagnosis of Williams-Beuren syndrome was made on the basis of the characteristic phenotype and cardiovascular findings; fluorescent in situ hybridization (FISH) or chromosomal microarray confirmation was not performed in this acute setting. Conclusion This case illustrates that Williams-Beuren syndrome should be considered in the differential diagnosis of infants presenting with unexplained, recurrent, or cyclic vomiting accompanied by hypercalcemia. Prompt recognition of the syndrome is essential, as targeted management-particularly the use of cinacalcet for refractory hypercalcemia-can lead to rapid clinical improvement and help prevent long-term complications.