Moyamoya disease is characterized by bilateral stenosis and/or occlusion of the 
terminal portion of the internal carotid artery. Moyamoya disease is prevalent 
among patients <10 years of age. Although most cases appear to be sporadic, 
approximately 10% occur as familial cases. The incidence of familial cases has 
been increasing because noninvasive diagnostic equipment, such as 
magnetic-resonance imaging and magnetic-resonance angiography, can detect the 
disease in almost all affected patients, including asymptomatic patients, during 
screening studies. In this study, we performed a total genome search to identify 
the location of a familial moyamoya disease gene in 16 families, assuming an 
unknown mode of inheritance. A linkage was found between the disease and markers 
located at 3p24.2-26. A maximum NPL score of 3.46 was obtained with marker 
D3S3050. This is the first genetic locus found to be involved in the molecular 
pathogenesis of familial moyamoya disease.