Sturge-Weber syndrome (SWS) is a noninherited congenital condition characterized by an extensive port-wine stain involving the V1 area (most frequently), eye abnormalities, and leptomeningeal and other brain abnormalities. In SWS, all 3 organ systems can be involved or a combination of systems. Glaucoma, often in the neonatal period, is a frequent association in up to 30% of patients with the syndrome. A number of neurological problems are associated and include epilepsy (which often has its onset in infancy or early childhood and is seen in a majority of patients with SWS), intellectual disability, hemiplegia, hemiatrophy, microencephaly, cortical blindness, increased intracranial pressure, and intracranial hemorrhage. Approximately 90% of patients have an activating somatic mutation in GNAQ, which encodes a G-protein subunit, in the affected tissues.