Introduction

Williams–Beuren syndrome (WBS) is a rare neurodevelopmental and multisystem genetic disorder caused by a microdeletion on chromosome 7q11.23, which affects approximately 26-28 genes, including the elastin (ELN) gene [1,2]. It is marked by a particular facial appearance, developmental delay, intellectual disability, a specific cognitive-behavioral profile with high sociability, and several congenital cardiovascular disorders [1]. The estimated prevalence of Williams syndrome (WBS) is between 1 in 13,700 and 1 in 25,000 live births [1].

Williams first reported the syndrome in 1961 [3], and Beuren in 1962 [4]. They both found that it was a unique combination of mental retardation, “elfin” facial features, a friendly personality, and congenital heart defects, most often supravalvular aortic stenosis (SVAS) [5]. In 1993, Ewart et al. identified the genetic defect responsible for WBS, a microdeletion of chromosome 7q11.23, involving the ELN gene in 95% of cases [5,6]. Arterial hypertension is a common complication, impacting up to one-third of individuals with WBS [7]. It may be caused by aortic coarctation, renal artery stenosis (RAS), or a more common narrowing of the vascular system [7,8]. We report a case of severe hypertensive emergency presenting in a child with Williams–Beuren syndrome to highlight the importance of early blood pressure screening and vascular assessment in this population.