Sturge-Weber syndrome (SWS) is a rare sporadic congenital neurocutaneous disorder with a prevalence of one in 50,000 births, and most cases are associated with an activating somatic mutation of the GNAQ gene in the affected tissues.1 SWS is often characterized by a facial capillary malformation known as port-wine stain and intracranial venous vascular abnormalities including leptomeningeal venous malformation (LVM). This evidence concerns the gene GNAQ and Sturge-Weber syndrome.