Severe Mitral Valve Regurgitation due to Significant Coronary Artery Stenosis in a 14-month-old boy with Williams-Beuren Syndrome

Introduction Williams-Beuren syndrome (WBS) is characterized by a combination of cardiovascular malformations, typical dysmorphic stigmata, a moderate developmental delay and behavioral abnormalities. According to the literature the incidence is within a range from 1:20 000 to 1:7 500 (Yildiz O et al., World J Pediatr Congenit Heart Surg 2015; 6: 311–316). Microdeletion of chromosome region 7q11.23 is pathognomonic, affecting the elastin gene (von Beust G et al., Klin Padiatr 2000; 212: 299–307). Due to reduced elastin content elasticity in the media of the arterial vessel wall is reduced, resulting in a vasculo…