An Adult Moyamoya Disease Confirmed by Ring Finger Protein 213 Gene Test and Radiological Studies

A 63-year-old female complained of transient dysarthria. MRA was conducted to evaluate this symptom, revealing distal internal carotid artery occlusion with collateral vessel development, suggesting Moyamoya disease, which had not been detected in MRA performed 5 years previously. Vascular risk factors and laboratory findings suggested no cardiac or autoimmune diseases. The diameter of stenosis of the middle cerebral artery on high-resolution MRI was 2.11 mm, and genetic evaluation revealed mutation of the gene encoding ring finger protein 213 (RNF213). High-resolution MRI and gene studies are useful for distinguishing between Moyamoya disease and atherosclerosis.