Sturge-Weber syndrome (SWS)
Sturge-Weber syndrome (SWS) is a rare, genetic condition that affects the eyes, skin and brain. It is defined by a facial capillary malformation (port wine stain), venous capillary malformations of the optic tract and venous capillary malformations of the leptomeninges (brain).
Children with port wine stains on the upper forehead are at greatest risk for SWS. Twenty-six percent will have the condition if the PWS partially involves the forehead. The risk is as high as 78% if the port wine stain affects a larger portion of the forehead (previously defined as the territory of the ophthalmic division of the trigeminal nerve on the face). The risk is greatest in children with port wine stains on both sides of the forehead.
Three main subtypes exist.
- Type 1 SWS. Facial port wine stain and neurologic disease with or without glaucoma
- Type 2 SWS. Facial port wine stain with or without glaucoma; no neurologic disease
- Type 3 SWS. Only neurologic symptoms
The symptoms of SWS occur because of the underlying vascular malformations in the skin, brain and eyes. The key features are facial port wine stain, glaucoma and seizures. Other neurologic impairments can be seen as well, including developmental delay and paralysis.
The diagnosis of a port wine stain is made clinically; no additional studies are required to confirm its presence. Radiologic imaging (MRI or CT scan) are needed to look for vascular malformations in the eyes and brain. Patients with port wine stains involving the upper face (and particularly the forehead) should be referred to an ophthalmologist to determine if glaucoma or other characteristic eye findings are present.
An activating mutation in the GNAQ (guanine nucleotide-binding protein alpha-q) gene has been identified in patients with SWS.
Treatment varies depending on the symptoms present and their severity. Port wine stains can be lightened with laser therapy. Seizures can be managed with anticonvulsant medications or surgical procedures, if severe. Similarly, management of glaucoma is determined by the extent of disease and the time of onset.