Fragile X Association of Australia represents individuals, and families and carers of people who have a Fragile X-associated Disorder. These conditions include Fragile X syndrome (FXS), Fragile X-associated Primary Ovarian Insufficiency (FXPOI), Fragile X-associated Tremor Ataxia syndrome (FXTAS) and Fragile X-associated Neuropsychiatric Disorders (FXAND).
From time to time Fragile X Association of Australia will prepare a position statement on an issue relevant to the Fragile X community.
One of the key issues in the management of Fragile X-associated disorders is appropriate, timely and accurate diagnosis and screening for Fragile X. The following statement presents the position of Fragile X Association of Australia on diagnosis and screening for Fragile X full mutation and premutation.
Diagnosis and Screening for Fragile X syndrome and Fragile X premutation carrier status
Fragile X Association of Australia (FXAA) strongly recommends:
(1) Diagnostic testing for children and adults with developmental delay and other indicators for the detection of Fragile X syndrome, in order to detect any Fragile X association and to offer appropriate treatment and management strategies;
(2) Diagnostic testing of embryos of women who have Fragile X carrier or Fragile X syndrome status and of any women who request it;
(3) Screening for Fragile X syndrome or Fragile X carrier status in all women prior to or in early pregnancy, in order to provide the widest range of family planning options; and
(4) Introduction in the future of screening of all newborn babies for Fragile X syndrome (newborn bloodspot screening) which is currently not available.
Some expanded information follows but it is strongly recommended that anyone interested in being tested discuss available options with their doctor or a genetic counsellor.
Various options exist and need to be accessed through a GP, paediatrician, obstetrician or any medical practitioner or genetic counsellor
(1) Diagnostic testing for males and females with a clinical reason for testing including autism spectrum disorder, intellectual disability, developmental delay of unknown cause, fertility problems, tremor/ataxia of unknown cause or family history of Fragile X-associated Disorders.
This is a relatively routine test that can be requested through most major pathology providers. There is a Medicare rebate for this test if the patient exhibits any Fragile X-associated Disorder 1 symptoms or if Fragile X syndrome has been diagnosed in the family. However, there may be some out of pocket costs.
(2) Diagnostic testing of embryos
Pregnant women with Fragile X syndrome or who have Fragile X carrier status can have a test of their foetus at 11 weeks with a result available in 3 weeks. They can then make a decision about their pregnancy based on the results of the test and in discussion with a genetic counsellor.
Another option is to use IVF and Pre-implantation Genetic Diagnosis (PGD) to ensure that non-FX embryos are used.
(3) Screening for women and men
Screening for Fragile X syndrome or Fragile X carrier status can be undertaken prior to pregnancy or early in pregnancy, and gives people information about their risk of having a child with Fragile X syndrome. People who have a relative with FXS or another Fragile X-associated Disorder have a higher risk of being a carrier of Fragile X than most people.
Carrier screening is also relevant for people who do not have a family history of Fragile X because many people who are carriers of Fragile X do not have anybody in their family who has Fragile X syndrome or another FX-associated Disorder. It is estimated that 1 in 250 women and 1 in 800 men are carriers of Fragile X.
Women who have Fragile X carrier status are at risk of having a child with Fragile X syndrome. Men who have Fragile X carrier status do not have children with Fragile X syndrome but pass the carrier status on to all their daughters.
If a woman learns that she is a FX carrier, Fragile X Association of Australia suggests arranging an appointment to see a genetic counsellor. A genetic counsellor will take a detailed family history, discuss the results, options for further testing if she is pregnant, options such as pre-implantation genetic diagnosis through IVF for future pregnancies, and can help with making decisions and providing support. The genetic counsellor can also discuss genetic testing for other relatives who may also be carriers.
FX carrier screening by DNA testing can be ordered by any medical doctor or through a clinical genetics service. The process involves a simple blood test or, in some cases, a cheek swab. The cost is covered by Medicare for people with a family history of FX-associated Disorders. For those without a family history, there is a charge (usually around $150-$200). Some services also offer carrier screening for other common inherited conditions alongside FX carrier testing. If you are interested in this it is worth discussing these options with a genetic counsellor, obstetrician or your GP.
(4) Newborn bloodspot screening for Fragile X syndrome
Newborn screening for Fragile X syndrome is currently not available in any state or territory of Australia.
The demonstrable benefits of early treatment and behavioural intervention, in addition to the identification of risk in subsequent and relatives’ pregnancies, present a strong argument in favour of newborn population screening for Fragile X syndrome. As both the degree of intellectual disability and behavioural problems are highly variable (especially in females with Fragile X syndrome), the average age at clinical diagnosis is significantly delayed in Australia (at around 5 years). Newborn bloodspot screening would remove this delay.
If you have any queries about diagnosis and screening for Fragile X syndrome and Fragile X premutation carrier status please contact our Helpline 1300 394 636 or email email@example.com