Sturge–Weber syndrome (SWS), also known as encephalofacial angiomatosis, is a neurocutaneous disorder named after English physician William Sturge and dermatologist Frederick Weber, who described its features in detail in 1869. Caused by congenital, nonhereditary (somatic) mosaic mutation of the gene GNAQ, this mutation disrupts vascular development, resulting in areas of abnormal vasculature on the face and intracranially and causing skin discoloration, leptomeningeal angiomatosis, and glaucoma.