Healthdirect Free Australian health advice you can count on.

Medical problem? Call 1800 022 222. If you need urgent medical help, call triple zero immediately

healthdirect Australia is a free service where you can talk to a nurse or doctor who can help you know what to do.

Illustration comparing a normal X chromosome (left) to an X chromosome (right) associated with fragile X syndrome.

Illustration comparing a normal X chromosome (left) to an X chromosome (right) associated with fragile X syndrome.
beginning of content

Fragile X syndrome

3-minute read

Fragile X syndrome is an inherited, life-long condition that can cause a range of problems. Early diagnosis and treatment can help those affected to reach their full potential.

What is Fragile X syndrome?

People with Fragile X syndrome (or Fragile X) have intellectual disability, behavioural and learning challenges as well as certain physical characteristics. Fragile X is the most common inherited cause of intellectual disability, and also the most common known genetic cause of autism. It affects around one in 4,000 males and around one in 6,000 females.

Fragile X is caused by a change in a single gene, the FMR-1 gene. This gene helps create a protein that is needed for healthy brain development.

Types of Fragile X syndrome

Depending on how a person’s FMR1 gene has been changed by the Fragile X mutation, they are said to either have the full mutation, or a pre-mutation.

People with the full mutation show symptoms of Fragile X. People with the pre-mutation may not show any symptoms, but are carriers of Fragile X.

Symptoms or signs of Fragile X syndrome

Fragile X can affect people differently. Girls and women are usually less affected than boys and men. A person may be fully affected by Fragile X but not show all of these signs below:

  • intellectual disability, slow development and difficulties with communication, coordination, motor skills and learning
  • behavioural and emotional features such as aggression, anxiety, shyness and repetitive speech
  • physical symptoms such as weak muscles and joints, a heart murmur and a high palate

Fragile X syndrome diagnosis

A diagnosis of Fragile X can be made at any age, by doing a blood test. This test can show whether or not someone is affected by Fragile X or whether they are a genetic carrier.

If you or your partner have Fragile X or are a carrier, and are expecting a baby, you might be able to get a pre-natal test to find out whether your baby will be affected.

Visit Pregnancy, Birth and Baby website for more information about Fragile X and babies.

Carriers of Fragile X

Carriers of Fragile X might develop certain health conditions later in life, such as:

  • Fragile X tremor ataxia syndrome, or FXTAS, which causes a tremor and mainly affects men over 50 years
  • Fragile X primary ovarian insufficiency, or FXPOI, which can cause infertility and early menopause in women

Living with Fragile X syndrome

Although there is no cure for Fragile X, treatments (including some medications) can help improve quality of life, especially if received early on. Ideally, each person with Fragile X will be cared for by a multidisciplinary team of health professionals.

Where to go for help

The Fragile X Association of Australia provides support to families living with Fragile X syndrome. This includes specialised clinics, workshops, genetic counselling and casework.

More information

Visit healthdirect's genetic disorders guide to learn more about genes, types of genetic disorders and where to go for help and more information.

Learn more here about the development and quality assurance of healthdirect content.

Last reviewed: June 2021


Back To Top

Need more information?

These trusted information partners have more on this topic.

Top results

Fragile X syndrome

People with Fragile X syndrome have intellectual disability, behavioural and learning challenges as well as certain physical characteristics.

Read more on Pregnancy, Birth & Baby website

Fragile X syndrome - Better Health Channel

The facts about fragile X syndrome are complicated, and parents and family members are invited to ask their doctor to refer them to a genetics clinic.

Read more on Better Health Channel website

Fragile X syndrome in children | Raising Children Network

Fragile X syndrome causes intellectual disability and other challenges. Early intervention and support helps children with Fragile X explore their abilities.

Read more on raisingchildren.net.au website

Fragile X messenger ribonucleoprotein 1 (FMR1) mutation | Pathology Tests Explained

The FMR1 gene contains the DNA code to produce a protein called FMRP. This protein is present in a variety of tissues but is especially important in t

Read more on Pathology Tests Explained website

Fragile X gene | Pathology Tests Explained

Fragile X CGG repeat sizing is routinely performed using a polymerase chain reaction (PCR) method with fluorescently labelled primers. The labelled pieces of

Read more on Pathology Tests Explained website

Genetic carrier screening

Screening for carrier status is a blood test to see if you carry genes that are linked to certain health conditions. Learn more about this test here.

Read more on Pregnancy, Birth & Baby website

How pathology helps IVF parents get pregnant | Know Pathology Know Healthcare

For IVF parents, pathology testing is vital from fertility tests before conception to ensuring a healthy pregnancy

Read more on Know Pathology Know Healthcare website

Genetic counselling

Genetic counselling may be recommended for people who have a history of hereditary disorders. Find out when genetic counselling can be helpful and what to expect.

Read more on Pregnancy, Birth & Baby website

Pregnancy tests amniocentesis - Better Health Channel

Amniocentesis is a prenatal procedure performed on a pregnant woman to withdraw a small amount of amniotic fluid from the sac surrounding the fetus.

Read more on Better Health Channel website

What is a congenital disorder?

Congenital disorder, also known as congenital disease or birth defects, are conditions present from birth. Find out more about congenital disorders.

Read more on Pregnancy, Birth & Baby website

Healthdirect 24hr 7 days a week hotline

24 hour health advice you can count on

1800 022 222

Government Accredited with over 140 information partners

We are a government-funded service, providing quality, approved health information and advice

Australian Government, health department logo ACT Government logo New South Wales government, health department logo Northen Territory Government logo Government of South Australia, health department logo Tasmanian government logo Victorian government logo Government of Western Australia, health department logo

Healthdirect Australia acknowledges the Traditional Owners of Country throughout Australia and their continuing connection to land, sea and community. We pay our respects to the Traditional Owners and to Elders both past and present.