**Core Concept**
Sturge-Weber syndrome is a rare neurocutaneous disorder characterized by the presence of a port-wine stain (a congenital vascular malformation) on the face, typically involving the ophthalmic division of the trigeminal nerve. This condition is associated with neurological abnormalities, including seizures, hemiparesis, and intracranial calcifications.

**Why the Correct Answer is Right**
Sturge-Weber syndrome is caused by a mutation in the GNAQ gene, leading to the activation of the MAPK signaling pathway. This results in the overexpression of vascular endothelial growth factor (VEGF), causing the characteristic port-wine stain. The syndrome also involves the development of intracranial calcifications, particularly in the cerebral cortex, which can be detected on radiographic imaging. The seizures and hemiparesis associated with Sturge-Weber syndrome are thought to result from the abnormal development of the cerebral cortex and the disruption of normal neuronal function.

**Why Each Wrong Option is Incorrect**
**Option A:** Neurofibromatosis is characterized by the development of neurofibromas, café-au-lait macules, and Lisch nodules, but it does not typically present with the features described in the question.

**Option B:** Tuberous sclerosis is a genetic disorder that affects multiple organ systems, including the skin, brain, kidneys, and heart. While it can cause seizures and intracranial calcifications, it is not typically associated with the characteristic port-wine stain or glaucoma of Sturge-Weber syndrome.

**Option D:** VHL (Von Hippel-Lindau syndrome) is a genetic disorder that predisposes individuals to develop hemangioblastomas of the retina and central nervous system, as well as renal cell carcinoma and pheochromocytoma. It does not typically present with the features described in the question.

**Clinical Pearl / High-Yield Fact**
Remember that Sturge-Weber syndrome is often associated with a leptomeningeal angioma, which can be detected on MRI imaging. This characteristic feature can help differentiate Sturge-Weber syndrome from other neurocutaneous disorders.

**✓ Correct Answer: C. Sturge-Weber syndrome**