Common conditions

Fragile X Syndrome

Fragile X is the commonest form of in-herited learning disorder in males.



  • Prevalence 1 in 5,700 in males with a full FRAXA mutation
  • Males affected
  • Females are usually unaffected carriers.
  • Some individuals carry smaller expansions.


Clinical presentation

  • Full mutations in males
  • Intelligence quotient is significantly reduced in males to approximately 41.
  • Developmental delay with hypotonia is common
  • Speech and language varies from no speech to mild . Individual rarely can speak fluently.
  • Behaviour is characterised by overactivity, impulsiveness, reduced concentration and poor social interaction often punctuated by aggression. Autistic spectrum features are common.
  • Many children have some degree of minor joint laxity.
  • Macrocephaly
  • Macro-orchidism
  • Large ears