Abstract
BACKGROUND: Williams syndrome (WS) (also as known Williams-Beuren Syndrome) is a neurodevelopmental disorder caused by deletion of chromosomes 7q11.23. WS phenotype is very variable but usually it is associated with a distinctive pattern of cognitive abilities. CASE PRESENTATION: 9-year-old female patient known case of developmental delay and precocious puberty presented to the emergency department with altered level of consciousness, elevated blood pressure of 230/160 with a provisional diagnosis of hypertensive encephalopathy. CONCLUSIONS: In our patient, the strongest indications for establishing the diagnosis included the classic elfin face and multisystemic involvement. Later on genetic analysis confirmed our diagnosis.