Abstract
Moyamoya disease (MMD) is a progressive cerebral arteriopathy characterized by stenosis and/or occlusion of the internal carotid arteries and the arteries around the Circle of Willis, with the development of "moyamoya" vessels, which are an attempt at revascularization at the base of the brain. In this paper we describe a 6 month, 3-week-old girl who presented with seizures and strokes due to moyamoya disease. The diagnosis of early onset MMD was made due to the magnetic resonance angiography results showing severe stenosis of the terminal/supraclinoid carotid arteries bilaterally with moyamoya vessels, and a completely novel de novo mutation in the RNF213 gene. She underwent bilateral encephaloduroarteriosynangiosis (EDAS) five months after her initial presentation and she did pretty well subsequently. She has shown no episodes suggestive of further strokes up to one year after surgery.