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Familial dyskinesia and facial myokymia

Disease definition

Familial dyskinesia and facial myokymia is a rare paroxysmal movement disorder, with childhood or adolescent onset, characterized by paroxysmal choreiform, dystonic, and myoclonic movements involving the limbs (mostly distal upper limbs), neck and/or face, which can progressively increase in both frequency and severity until they become nearly constant. Patients may also present with delayed motor milestones, perioral and periorbital dyskinesias, dysarthria, hypotonia, and weakness.


Classification level: Disorder
  • Synonym(s):
    • FDFM
  • Prevalence: <1 / 1 000 000
  • Inheritance: Autosomal dominant 
  • Age of onset: Childhood
  • ICD-10: G51.4
  • OMIM: 606703
  • UMLS: C1847627
  • MeSH: -
  • GARD: 12722
  • MedDRA: -

Detailed information


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