Moyamoya is the name given to a cerebral angiographic picture of bilateral intracranial carotid artery occlusion associated with telangiectatic vessels in the region of the basal ganglia. The Japanese word moyamoya means 'something hazy like a puff of ... Moyamoya is the name given to a cerebral angiographic picture of bilateral intracranial carotid artery occlusion associated with telangiectatic vessels in the region of the basal ganglia. The Japanese word moyamoya means 'something hazy like a puff of cigarette smoke, drifting in the air.' Hemiplegia of sudden onset and epileptic seizures constitute the prevailing presentation in childhood, while subarachnoid bleeding occurs more frequently in adults (summary by Suzuki, 1986). - Genetic Heterogeneity of Moyamoya Disease Susceptibility to moyamoya disease-2 (MYMY2; 607151) is caused by variation in the RNF213 gene (613768) on chromosome 17q25. Moyamoya disease-5 (MYMY5; 614042) is caused by mutation in the ACTA2 gene (102620) on chromosome 10q23.3. Loci for the disorder have been mapped to chromosome 3p (MYMY1) and chromosome 8q23 (MYMY3; 608796). See also MYMY4 (300845), an X-linked recessive syndromic disorder characterized by moyamoya disease, short stature, hypergonadotropic hypogonadism, and facial dysmorphism.
Juvenile patients with moyamoya disease initially present with transient motor disturbances resulting from transient brain ischemia, whereas adults present with intracranial hemorrhage. The symptoms in juvenile patients are due to the narrowing or occlusion of the circle of ... Juvenile patients with moyamoya disease initially present with transient motor disturbances resulting from transient brain ischemia, whereas adults present with intracranial hemorrhage. The symptoms in juvenile patients are due to the narrowing or occlusion of the circle of Willis, and those in adults are due to a collapse of collateral circulation, which gradually develops as a result of the occlusion of the carotid fork at a younger age. Approximately 10% of cases are familial, with approximately 76% occurring in sibs and 24% in a parent and offspring. Because of noninvasive diagnostic methods, the identification of familial cases has increased through the finding of asymptomatic family members (Suzuki, 1986). Soriani et al. (1993) reported a case of childhood moyamoya disease with clinical onset of neurologic symptoms in the third year of life; during the child's illness, the maternal grandmother presented with moyamoya disease also. Antiplatelet-aggregating and calcium-antagonist drugs seemed effective in preventing further vascular accidents. Kikuchi et al. (1995) reported moyamoya disease in 3 sibs, a 6-year-old girl and 4-year-old twin boys. No information was provided about the rest of the family. Dobson et al. (2002) conducted a retrospective study to determine whether the presence of moyamoya collaterals influenced the risk of recurrence of cerebrovascular events in patients with sickle cell disease (603903) placed on chronic transfusions after a stroke. They studied 43 patients with homozygous sickle cell anemia and 1 with HbSO (Arab) (141900.0245) who had suffered strokes before age 18 years. They found that up to 41% of patients with sickle cell disease experienced recurrent cerebrovascular events, stroke or transient ischemic attack, despite chronic transfusions and that the risk of recurrence was significantly higher for those who had moyamoya collaterals. Nagel (2002) commented that the same gene (or a related gene) found in the Japanese familial form of moyamoya disease is involved in a 'multigenic origin of the phenotype' in this complication of a monogenic disorder.
The disorder occurs more frequently in females (male-to-female ratio of 2:3) and is prevalent among patients less than 10 years of age (Suzuki, 1986). Sakurai et al. (2004) stated that the peak age of onset is 10 to ... The disorder occurs more frequently in females (male-to-female ratio of 2:3) and is prevalent among patients less than 10 years of age (Suzuki, 1986). Sakurai et al. (2004) stated that the peak age of onset is 10 to 14 years, with a smaller peak of onset age in the 40s. A high incidence of moyamoya disease is found in Asia, predominantly in Japan (Ikezaki et al., 1997). No single region of Japan has an unusually high incidence (Goto and Yonekawa, 1992). Yamauchi et al. (2000) stated that Moyamoya disease is the 'most critical cause of childhood stroke in the Japanese population.'