Moyamoya disease in a child with glycogen storage disease type Ia.

A three-year-old child affected by glycogen storage disease (GSD) type Ia presented with acute hemiplegia secondary to Moyamoya disease. So far, the association of moyamoya with GSD Ia had only been reported twice. The rarity of both conditions makes their association unlikely to be a chance event and an etiological relationship between them must be considered.