Search for a rare disease

* (*) mandatory field

Other search option(s)

Suggest an update

(*) Required fields.


Only comments seeking to improve the quality and accuracy of information on the Orphanet website are accepted. For all other comments, please send your remarks via contact us. Only comments written in English can be processed.

Orphanet doesn't provide personalised answers. To get in touch with the Orphanet team, please contact

Information provided in your contribution (including your email address) will be stocked in .CSV files that will be sent as an email to Orphanet's teams. These emails might be conserved in the teams' mailboxes, in our backoffice servers but will not be registered in our databases (for more information see our section General Data Protection Regulation and data privacy (GDPR) and Confidentiality).

Captcha image

Moyamoya disease

Disease definition

Moyamoya disease (MMD) is a rare intracranial arteriopathy involving progressive stenosis of the cerebral vasculature located at the base of the brain causing transient ischemic attacks or strokes.


Classification level: Disorder
  • Synonym(s):
    • Idiopathic Moyamoya disease
  • Prevalence: 1-9 / 1 000 000
  • Inheritance: Multigenic/multifactorial or Autosomal dominant or Autosomal recessive or X-linked recessive 
  • Age of onset: All ages
  • ICD-10: I67.5
  • ICD-11: 8B22.B
  • OMIM: 252350  607151  608796  614042
  • UMLS: C0026654
  • MeSH: D009072
  • GARD: 7064
  • MedDRA: 10028047

Detailed information

General public


Disease review articles


ERN produced/endorsed by ERN(s)   FSMR produced/endorsed by FSMR(s)
The documents contained in this web site are presented for information purposes only. The material is in no way intended to replace professional medical care by a qualified specialist and should not be used as a basis for diagnosis or treatment.