Orphanet: Fragile X syndrome

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Fragile X syndrome

Disease definition

A rare genetic disease associated with mild to severe intellectual deficit that may be associated with behavioral disorders and characteristic physical features including a high forehead, prominent and large ears, hyperextensible finger joints, flat feet with pronation and, in adolescent and adult males, macroorchidism.


Classification level: Disorder
  • Synonym(s):
    • FRAXA syndrome
    • FXS
    • FraX syndrome
    • Martin-Bell syndrome
  • Prevalence: 1-5 / 10 000
  • Inheritance: X-linked dominant 
  • Age of onset: Neonatal, Infancy, Childhood
  • ICD-10: Q99.2
  • OMIM: 300624  311360
  • UMLS: C0016667  C0751156
  • MeSH: D005600
  • GARD: 6464
  • MedDRA: 10017324

Detailed information

Article for general public


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