Fragile X is thought to be the most common inherited form of learning disability.

It is usually caused by an X chromosome that carries a mutation of a particular gene. It is a genetic defect and may be inherited. Fragile X is twice as common in boys as in girls and its effects are milder in girls. It is thought that this is because girls have two X chromosomes and that one can perhaps compensate for the other.

Fragile X affects behaviour, emotions, learning, speech and language. The range of effects is great and it is not possible to predict which of the many potential difficulties a child with fragile X will have. Indeed, it is possible for a child to have the damaged gene and yet not be affected by it at all. Children with fragile X often have high verbal abilities and have a good sense of humour. It is important however to ensure that the child with fragile X is not subjected to too many environmental stimuli (eg. sounds, movements, smells) at once. Children with fragile X are sometimes given medication to improve their concentration.

Key characteristics

A child with fragile X syndrome may:

  • repeat words and phrases, or the last words in a sentence, over and over
  • fail to respond to direct questions
  • give answers not obviously related to the question
  • speak in rapid bursts
  • have poor fine and gross motor coordination
  • dislike work based on writing
  • find large, noisy, unstructured group times distressing
  • find it easier to learn in the morning, after a settling-in period
  • become distressed by eye contact, touch, questioning in front of others
  • react badly to pressures of time
  • be oversensitive to relatively minor upsets and/or have disruptive outbursts
  • prefer practical, physical activities
  • have slight motor coordination problems
  • enjoy repetitive tasks, which may have a calming effect
  • have subtle physical characteristics, such as a large head, long face, large jaw, protruding ears, high palate or dental overcrowding.

Support strategies

You may need to:

  • provide as much positive attention as possible
  • have an organised set of routines and make sure that the child is notified of any changes in these routines well in advance
  • set up an agreed reward system for good behaviour, rather than using too many sanctions for inappropriate behaviour
  • reward specific behaviours and explain this clearly
  • praise every small achievement
  • make use of visual clues
  • give short, simple instructions – for complex tasks, give only one or two instructions at a time
  • be consistent in the use of rules and routines
  • let children work in an individual or paired situation, rather than expecting them to work in groups
  • be realistic in your expectations, setting short, clearly defined targets.

Support agencies

Fragile X Society (UK)
National Fragile X Foundation (US)