Fragile X Syndrome
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Our bodies are made up of trillions of cells.
In each cell, there are tiny structures called “Chromosomes”.
Most of us receive 23 chromosomes from our mother and 23 chromosomes from our father (46 in total).
On chromosome X there is a gene called FMR1.
FMR1 is responsible for producing a protein called FMRP that helps our brain to function.
The FMR1 gene begins with a series of repeated letters known as “CGG”.
Most people will have less than 55 copies of “CGG”.
When someone is diagnosed with Fragile X Syndrome it means there’s a problem with FMR1 and that they have over 200 copies of “CGG”.
This can result in chromosome X looking “broken”.
There are also people who are just carriers of Fragile X Syndrome. This means they have between 55-200 copies of “CGG”.
Carriers of Fragile X Syndrome can show no symptoms, however, can still pass it on to their children.
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Carriers of Fragile X Syndrome are at risk of experiencing:
Fragile X Associated Primary Ovarian Insufficiency (FXPOI): Causes females to experience fertility problems and early menopause.
Fragile X Associated Disorders (FXAD): Causes problems with balance, speech, memory, and intellectual ability.
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Fragile X Syndrome involves a wide range of symptoms and severities which means that every person will present differently.
Symptoms can include:
Having an Intellectual Disability
Having Anxiety
Physical features
Long narrow face
Large ears
Flat feet
Seizures
Difficulty processing sensory information
Limited eye contact
Repeating words or phrases but not understanding how to use them in conversation
Repetitive body movements, for e.g. flapping their hands
Short attention span
Struggling to focus and concentrate on tasks
Self-harming behaviours, for e.g. biting their hands
Difficulty learning
Not speaking or delayed speech
Difficulty sleeping
High blood pressure
Weak muscles
Problems with hearing
Problems with eyesight
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Fragile X Syndrome is caused by a person having over 200 copies of “CGG” in the FMR1 gene.
It can be inherited by either the mother or father.
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Fragile X Syndrome can be diagnosed before birth with prenatal tests.
After birth, Fragile X Syndrome can be confirmed with a blood test.
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While there is no cure for Fragile X Syndrome, diagnosis and specifically tailored treatment are important for improving quality of life.
Services available to help with Fragile X Syndrome include:
Paediatrician: A Paediatrician can help treat and provide routine childhood care.
Psychology: A Psychologist can help to develop emotion regulation skills.
Positive Behaviour Support: A Behaviour Support Practitioner can help to understand behaviours of concern, provide strategies, and build skills.
Occupational Therapy: An Occupational Therapist can support independence and participation in daily life.
Speech Pathology: A Speech Pathologist will focus on developing communication skills.
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Fragile X Syndrome is the most common cause of inherited Intellectual Disability.
Fragile X Syndrome affects more males than females.
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Better Health
https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/fragile-x-syndrome
Cleveland Clinic
https://my.clevelandclinic.org/health/diseases/5476-fragile-x-syndrome
Fragile X Association of Australia
https://www.fragilex.org.au/understanding-fragile-x/
Health Direct
https://www.healthdirect.gov.au/fragile-x-syndrome
Medline Plus
https://medlineplus.gov/genetics/condition/fragile-x-syndrome/
National Fragile X Foundation
https://fragilex.org/understanding-fragile-x/fragile-x-101/
National Institute of Child Health and Human Development
https://www.nichd.nih.gov/health/topics/fragilex
Raising Children Network
The Royal Australian College of General Practitioners
https://www.racgp.org.au/afp/2017/july/fragile-x-associated-disorders-don-t-miss-them
U.S. Centers for Disease Control and Prevention
Fragile X Syndrome is a genetic condition that causes changes to the FMR1 gene that is in chromosome X.
Written by Cindy Queiroz
Last updated: April 2025