Familial occurrence of moyamoya disease in the mother and four daughters including identical twins.

Familial occurrence of moyamoya disease is described in the mother and four daughters, including identical twins. Physical examination findings on admission were all normal and no mental retardation was observed. The third daughter had suffered from a ventricular septal defect when aged 6 years, but the others all had unremarkable past histories. Four of the five patients presented with transient ischemic attack as the initial symptoms, but one patient remains asymptomatic. Two patients had had repeated transient ischemic attacks. Cerebral angiography revealed either stenosis or occlusion of the intracranial portion of the bilateral internal carotid arteries associated with moyamoya vessels in all patients. The findings of moyamoya disease in a parent and four siblings including identical twins suggest that genetic factors are important in the pathogenesis of moyamoya disease.