About Fragile X syndrome

Fragile X syndrome is a genetic condition. It's the most common cause of genetically inherited intellectual disability.

Children with Fragile X can find it hard to understand and process information. These difficulties mean they can have problems with learning, behaviour and development.

Children with Fragile X can also have autism spectrum disorder-like behaviours. Some children have enough of these behaviours to meet the criteria for an autism spectrum disorder (ASD) diagnosis. Fragile X is the most common, known single-gene cause of ASD.

Fragile X affects more boys than girls and also affects boys more severely than girls. Fragile X appears in children of all cultures and ethnic backgrounds.

Fragile X carriers
People can be carriers of Fragile X syndrome without having the condition themselves. This means they have a type of Fragile X gene that they can pass on to their children.

Male and female carriers of Fragile X can develop Fragile X-associated tremor/ataxia syndrome (FXTAS) when they're over 50 years old. This condition is more common in men than women.

Some female carriers suffer from Fragile X-associated primary ovarian insufficiency (FXPOI). This problem can lead to infertility and early menopause in women with the gene.

Signs and symptoms of Fragile X

The signs and symptoms of Fragile X can vary a lot from child to child. Some children are very obviously affected, whereas others have more subtle symptoms.

Physical characteristics
Fragile X can be hard to spot physically. But some children with Fragile X might have the following physical features:

  • long and narrow face
  • prominent ears
  • poor muscle tone – which can cause crossed eyes or a squint, extra curve in the spine or slack face muscles (particularly in young children)
  • loose joints (‘double joints’) that move a lot more than usual
  • flat feet.

Cognitive signs
Intellectual disability and developmental delay are the most common features of Fragile X. Many children with Fragile X also have difficulties with fine motor skills, gross motor skills and delayed speech development.

Behaviour signs
If your child has Fragile X, you might notice that your child behaves differently from other children or has delayed development – for example, he might have tantrums because he hasn’t learned other ways to express and manage his feelings.

Other common signs of Fragile X include:

Associated medical concerns
Children with Fragile X can have other medical concerns like:

If your child has these problems, your paediatrician can diagnose them and help you find ways to manage them in everyday life.

Ability not disability

Children with Fragile X often have a strong sense of humour and enjoy having fun, which can help overcome their social anxieties. And they’re often really good at things like:

  • learning visually using pictures or computers
  • remembering things like songs, movies or sports events
  • undertaking practical, relevant tasks
  • doing essential daily tasks
  • being compassionate, helpful and friendly.

Children learn the most from the people who care for them and with whom they spend most of their time, so everyday play and communication with your child can help a lot.

Diagnosis and testing for Fragile X syndrome

Fragile X can be diagnosed at any age, from before birth to adulthood. But the earlier it’s spotted the better, because early treatment can help children reach their full potential.

All children who have an intellectual disability, developmental delay or autism spectrum disorder (ASD) should be tested for Fragile X.

It’s also a good idea to have your child tested for Fragile X if:

  • your family has a history of Fragile X syndrome, intellectual disability or developmental delay
  • your child has the physical features or behaviour typical of Fragile X (regardless of family history)
  • your child has significant learning problems, trouble with understanding, ADHD or anxiety.

Your GP or paediatrician (or any other medical doctor) can order a DNA test to find out whether your child has Fragile X. It takes 2-3 weeks to get test results back, depending on which state of Australia you live in.

In some circumstances, Medicare might cover the cost of tests for Fragile X. For more information, see your GP or paediatrician.

Testing for Fragile X syndrome before or during pregnancy

If you’re pregnant or planning a pregnancy you might want to have testing done to find out whether you’re at risk of having a child with Fragile X syndrome.

All women can have Fragile X carrier testing, but Medicare funding is available only for women with a family history of Fragile X. If you’re pregnant and find out you're a Fragile X carrier, your baby can be tested for Fragile X by chorionic villus sampling (CVS) or amniocentesis.

Before you go ahead with antenatal testing for Fragile X, you might want to think about genetic counselling. Genetic counselling will help you understand your options and the effect a diagnosis might have on you and your family. A genetic counsellor can also support you as you make your decisions.

DNA tests are important for diagnosing genetic conditions like Fragile X syndrome. Our article on genetic testing has more information about DNA tests, what you can expect and some of the things you need to know beforehand.

Early intervention services for children with Fragile X syndrome

Although there’s no cure for Fragile X syndrome, early childhood intervention services can improve outcomes for your child. Through early intervention services, you can work with health professionals to choose treatment and therapy options and learn ways of supporting your child so that she can reach her full potential.

The best treatment for Fragile X involves using a multidisciplinary approach to look after your child's educational, behavioural and medical needs in combination. This means you might have a team of different professionals involved in supporting you and your child, including paediatricians, genetic counsellors, occupational therapists, physiotherapists, psychologists, special education teachers and speech pathologists.

Financial support for children with Fragile X syndrome

If your child has a confirmed diagnosis of Fragile X syndrome, your child can get support under the National Disability Insurance Scheme (NDIS). The NDIS helps you get services and support in your community, and gives you funding for things like early intervention therapies or educational support.

If you live in an area that isn’t yet covered by the NDIS, your child can get funding under the Better Start for Children with Disability initiative. If your child is eligible for the NDIS, he can move to the NDIS when it comes to your area. Read our NDIS and Better Start FAQs for more information.

Looking after yourself and your family

Although it’s easy to get caught up in looking after your child, it’s important to look after your own wellbeing too. If you’re physically and mentally well, you’ll be better able to care for your child.

If you need support, a good place to start is with your doctors and genetic counsellors.

You can also get support from the Fragile X Association of Australia (FXAA). The FXAA provides support to families affected by Fragile X. It offers a range of services including counselling, clinical services, parent support, research and education groups. You can call the FXAA on 1300 394 636.

Talking to other parents can also be a great way to get support. You can connect with other parents in similar situations by joining a face-to-face or an online support group.

If you have other children, these siblings of children with disability need to feel that they’re just as important to you – that you care about them and what they’re going through. It’s important to talk with them, spend time with them, and find the right support for them too.