Fragile X syndrome

Martin Bell syndrome, Fra(X) syndrome, FRAXA syndrome, FXS, Marker X syndrome

What is fragile X syndrome?

Fragile X syndrome is a genetic condition that causes developmental delays and cognitive impairment.

It is the most common cause of inherited intellectual disability in males.

Females with fragile X syndrome usually have milder symptoms.

What causes fragile X syndrome?

Fragile X syndrome is caused by a mutation in a gene that plays a role in the development of synapses, which are connections between nerve cells.

When this gene is mutated, it prevents the production of a protein known as FMRP.

FMRP is important for the normal functioning of the nervous system, and its absence can lead to a variety of developmental and cognitive issues.

What are the symptoms of fragile X syndrome?

When the nervous system is disrupted by the lack of FMRP being produced, it can cause:

  • Delayed speech and language
  • Anxiety and depression
  • Impulsive actions
  • Attention deficit disorder

Physical features can include:

  • Long and narrow face
  • Large ears
  • Prominent jaw and forehead
  • Flexible joints
  • Soft skin

If you are concerned that your child may have fragile X syndrome, it is important to see a doctor for a diagnosis.

Are you affected by fragile X syndrome?

If you’re affected by fragile X syndrome, The Brain Charity can support you.

We are the only charity in the UK to be here for every one of the more than 600 different neurological conditions in existence. Individually, many are rare, but combined, they affect 1 in 6 people.

We provide practical help on all aspects of living with fragile X syndrome, emotional support such as counselling, phone befriending and group therapy and social activities to people with fragile X syndrome from all over the UK from our centre in Liverpool.

Looking to talk to someone?

Woman smiling, making eye contact and holding the hand of another woman to comfort her

Phone us

Contact The Brain Charity now

Our friendly Information & Advice Officers are here to help. We endeavour to respond to all enquiries within 10 working days.

0151 298 2999

Looking to talk to someone?

  • Please tell us which neurological condition you are affected by and what you need support with.

Caring for someone with fragile X syndrome

We support carers, friends and family too

Are you a carer for or relative of someone with fragile X syndrome? It’s just as important for you to look after your own physical and mental wellbeing too.

The Brain Charity provides free support for carers, friends and family of people with any form of neurological condition, including fragile X syndrome, from anywhere in the UK.

We also run an additional carers advocacy service for all carers in Liverpool, regardless of which type of condition the person they care for has.

You don’t need to be a formal or registered carer

We can help you even if you don’t view yourself as a formal carer or claim Carer’s Allowance. Find out some of the ways we support carers below.

Other resources

The Brain Charity's library

The Brain Charity’s library has a range of resources on fragile X syndrome, as well as many other disability related issues.

Support groups

Support groups at The Brain Charity

Are you interested in setting up a fragile X support group, or do you already run one? Email to let us know.

Alternatively, you can check out our list of related support groups here.

Other charities

Contact. A charity for families with disabled children