Fragile X Syndrome: The basics you need to know

August 19, 2015

Fragile X syndrome is the most common, inherited cause of learning disability: affecting around 15,000 people in the UK (around 1 in 4,000 men or boys and 1 in 6,000 girls and women are living with the condition).


What are the characteristics of Fragile X?


Every person with Fragile X is different, but we know that there are patterns of strengths and challenges associated with having Fragile X. One of the greatest challenges, faced by the majority of people with Fragile X, is high levels of anxiety. Social situations, especially with unfamiliar people, can be particularly anxiety-provoking, and people with the condition will often show autistic-like behaviours (such as avoiding eye contact, withdrawing, flapping hands or asking repetitive questions) to help manage their anxiety. Being the focus of others attention, even when this is just being asked a direct question, can be difficult. As a result of these behaviours, around 30% of people with fragile X meet the criteria for an additional diagnosis of autism. Despite these anxieties, however, people with Fragile X are typically very sociable and conscious of others. Simple changes, such as not pressuring eye contact or by giving the person the time and space to feel comfortable, can help to make a real difference.


This characteristic anxiety can be triggered by many different situations for different people. Busy or unfamiliar environments and transitions (even small transitions such as getting out the car) can be especially challenging. This is often exacerbated by sensory processing problems, which can also make day-to-day events seem overwhelming. Individuals may sometimes show behaviours that challenge those supporting them, but this is most commonly their communication of rising anxiety levels or a situation they are finding difficult.


Individuals with Fragile X often have strong visual memories and respond well to visual cues, meaning visual schedules and cues can be particularly useful. Also, people affected by fragile X have relative strengths with simultaneous processing (taking things in as a whole) and more problems with sequential processing (thinking through how to execute a task step-by step). This means that it can be helpful to show all steps in a process visually, when helping someone prepare for an activity.


As its name would suggest Fragile X Syndrome is carried on the X chromosome. This means that there are differences, in general, how the condition affects males and females. Girls and women have two X chromosomes, meaning that their 2ndX can, to varying degrees, compensate for the effects of their “fragile” X. However Males have one X and one Y chromosome, and so they do not have a 2nd compensatory X. As a result, males are typically (though not always) more severely affected than females. For instance, almost all (around 95%) boys and men with fragile X have a learning disability (which may vary from mild to severe), compared to around 60% of girls and women. There are some women with the full Fragile X gene variant who do not experience any day-to-day effects of the condition. However, some females have more severe effects than some males, or some have more subtle but challenging effects of Fragile X. It is important for the needs of girls and women, who may be in some ways less clearly affected, to also be recognised and supported. In mainstream settings, the shyness and anxiety can be particularly challenging and a barrier to social, educational and work opportunities, for instance.


Why is getting the right diagnosis important?


Each person with fragile X is different, and having the label of “Fragile X Syndrome” does not define them. However, getting the right diagnosis is important because understanding the condition means that proactive support can be provided where we know that people may experience challenges and can also point towards interventions that can be more effective, when people are facing difficulties.


Also, as fragile X is a directly inherited condition, any diagnosis within a family has implications for other family members. There is more information on the genetics of fragile X in our introductory booklet, which can be downloaded at!booklets/csl


How can the condition be diagnosed?

The only way that Fragile X can be diagnosed by a genetic (blood) test: it cannot be diagnosed based on appearance or behaviour. These genetic tests are carried out at regional genetic centres based in larger hospitals and the referral must be made by a medical professional. Diagnosis is often in childhood, but, at the Society, we have come across people being diagnosed in adulthood.


How we can help

The Fragile X Society has 3 Support Workers (contact details, below), who all have a background experience in learning disability. We take enquiries from individuals and families affected by Fragile X and professionals working in the field. We have information on the syndrome, including best practice for supporting individuals affected by fragile X. There is also more information on fragile X, including details of our eLearning resource, available on our website


You can also join in our chat with WeLDNurses on Tuesday 1st September at 8.30pm (with special guest co-host Professor Jeremy Turk), to discuss health problems and behaviour associated with Fragile X Syndrome.

Please do contact us if you are working with someone with Fragile X, or if you want to know more. We are here to provide information, as well as support





Jane Oliver

Family Support Worker taking enquiries about adults in England, Wales and N Ireland

Wednesday – Friday 9.00-5.00

01371 875100




Wendy Bowler

Family Support Worker taking enquiries in England, Wales and N Ireland

Monday – Thursday 9.00-5.00

01371 875100





Sandra Thoms

Family Support Worker taking all enquiries in Scotland

Monday – Thursday 9.00-5.00

07825 050072






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