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Disease Profile

Moyamoya disease

Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.

1-9 / 1 000 000

US Estimated

Europe Estimated

Age of onset

All ages





Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease.


Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype.


dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.


recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.


Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.

Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.


Not applicable


Other names (AKA)

Moyamoya syndrome; Spontaneous occlusion of the circle of Willis; MYMY


Congenital and Genetic Diseases; Nervous System Diseases


Moyamoya disease is a rare, progressive, blood vessel disease caused by blocked arteries at the base of the brain in an area called the basal ganglia. The name "moyamoya" means "puff of smoke" in Japanese and describes the look of the tangled vessels that form to compensate for the blockage. This condition usually affects children, but can affect adults. Affected people are at increased risk for blood clots, strokes, and transient ischemic attacks (TIAs) which are frequently accompanied by seizures and muscular weakness, or paralysis on one side of the body. Affected people may also have disturbed consciousness, speech deficits (usually aphasia), sensory and cognitive impairments, involuntary movements, and vision problems. Researchers believe that Moyamoya disease is an inherited condition because it tends to run in families.[1]

Moyamoya syndrome is a related term that refers to cases of moyamoya disease that occur in association with other conditions or risk factors, such as neurofibromatosis, tuberculosis meningitis, sickle cell disease, leptospirosis, brain tumors, Sturge-Weber syndrome, and tuberous sclerosis.[2]


This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

Medical Terms Other Names
Learn More:
80%-99% of people have these symptoms
30%-79% of people have these symptoms
Abnormality of the cerebral vasculature
Abnormality of the cerebral blood vessels
Intellectual disability
Mental deficiency
Mental retardation
Mental retardation, nonspecific

[ more ]

Percent of people who have these symptoms is not available through HPO
Autosomal recessive inheritance
Carotid artery occlusion
Obstructed carotid artery
Inflammatory arteriopathy


In some families, risk for moyamoya disease is inherited. Changes in the RNF213 gene have been associated with the condition. There are other gene changes involved in moyamoya disease, that remain to be found. Factors such as infection or inflammation, likely also play a role in the condition's development in these families.[3]

Other people develop moyamoya syndrome or phenomenon. Moyamoya syndrome can occur in association with many different conditions, such as with infections, atherosclerosis (clogged arteries), blood disorders (for example sickle cell disease or beta thalassemia), vasculitis, autoimmune conditions (for example Lupus, thyroid disorders, Sneddon syndrome), connective tissue disorders (for example neurofibromatosis (NF) type 1 or Tuberous sclerosis), chromosome disorders, metabolic diseases, head trauma or radiation, brain tumors, and heart disease, to name a few.[3]


Treatment for Moyamoya disease should begin early in the disease course to prevent severe complications.[4] Surgery is the mainstay of treatment, and is the only viable long-term treatment.[5] There are several types of revascularization surgeries that can restore blood flow to the brain by opening narrowed blood vessels, or by bypassing blocked arteries. While children usually respond better to revascularization surgery than adults, the majority of individuals have no further strokes or related problems after surgery.[6]

No medication can stop the narrowing of the brain's blood vessels, or the development of the thin, fragile vessels that characterize the disease.[5] However, medications are used to treat many of the symptoms of the disease, and are often an important part of the management. Medications may include aspirin (to prevent or reduce the development of small blood clots); calcium channel blockers (which may improve symptoms of headaches and reduce symptoms related to transient ischemic attacks); and antiseizure medications (when needed for a seizure disorder). In a few cases, anticoagulants may be needed for people with unstable or frequent symptoms. However, they are not used long-term due to the risk of cerebral bleeding.[7]

Additional information about the treatment of Moyamoya disease is available on Medscape Reference's Web site.

People interested in learning about specific treatment options for themselves or family members should speak with their health care provider.

Management Guidelines

  • Project OrphanAnesthesia is a project whose aim is to create peer-reviewed, readily accessible guidelines for patients with rare diseases and for the anesthesiologists caring for them. The project is a collaborative effort of the German Society of Anesthesiology and Intensive Care, Orphanet, the European Society of Pediatric Anesthesia, anesthetists and rare disease experts with the aim to contribute to patient safety.

Learn more

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

In-Depth Information

  • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
  • MeSH® (Medical Subject Headings) is a terminology tool used by the National Library of Medicine. Click on the link to view information on this topic.
  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Moyamoya disease. Click on the link to view a sample search on this topic.


  • The Boston Children's Hospital has live videos on Moyamoya disease. Click on Boston Children's Hospital to choose a video to watch.


  1. NINDS Moyamoya Disease Information Page. National Institute of Neurological Disorders and Stroke (NINDS). March 2011; https://www.ninds.nih.gov/Disorders/All-Disorders/Moyamoya-Disease-Information-Page. Accessed 9/19/2011.
  2. Smith ER & Scott RM. Moyamoya: epidemiology, presentation, and diagnosis. Neurosurg Clin N Am. July 2010; https://www.ncbi.nlm.nih.gov/pubmed/20561502. Accessed 9/19/2011.
  3. Suwanwela NC. Moyamoya disease: Etiology, clinical features, and diagnosis. In: Biller J, Nordli DR. UpToDate. Waltham, MA: UpToDate; 2015; Accessed 7/27/2015.
  4. Josette Mancini. Moyamoya Disease. Orphanet. September, 2006; https://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=EN&Expert=2573. Accessed 7/2/2014.
  5. Edward Smith. Moyamoya Disease. Boston Children's Hospital. 2011; https://www.childrenshospital.org/health-topics/conditions/m/moyamoya-disease. Accessed 7/2/2014.
  6. Moyamoya Disease Information Page. NINDS. April 16, 2014; https://www.ninds.nih.gov/Disorders/All-Disorders/Moyamoya-Disease-Information-Page. Accessed 7/1/2014.
  7. Moyamoya syndrome. NORD. January 20, 2012; https://www.rarediseases.org/rare-disease-information/rare-diseases/byID/617/viewAbstract. Accessed 7/2/2014.
  8. Roy Sucholeiki. Moyamoya Disease. Medscape Reference. January 25, 2012; https://emedicine.medscape.com/article/1180952-overview. Accessed 7/1/2014.
  9. Nijasri Charnnarong Suwanwela. Moyamoya disease: Treatment and prognosis. UpToDate. Waltham, MA: UpToDate; July, 2014; Accessed 7/2/2014.
  10. Fernandez-Alvarez E, Pineda M, Royo C, Manzanares R. "Moya-moya' disease caused by cranial trauma. Brain Dev. 1979; 1(2):133. Accessed 7/27/2015.
  11. Moyamoya disease. Genetics Home Reference. April 2015; https://ghr.nlm.nih.gov/condition/moyamoya-disease. Accessed 7/27/2015.

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