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prepair™ genetic carrier screening: Q&A with Associate Genetic Counsellor Dr Alison Archibald

Institute News
Tuesday, November 14, 2017 - 3:30pm

The Victorian Clinical Genetics Services (VCGS) is a not-for-profit provider of genetic tests and genetic counselling services. Below, VCGS Associate Genetic Counsellor Dr Alison Archibald answers some common questions about the prepair™ genetic carrier screening test.

What is genetic carrier screening?

Genetic carrier screening gives you information about your chance of having a child with a genetic condition. Genes provide the instructions for our bodies to grow, develop and function. Genetic conditions are caused by changes in our genes. Some people carry certain gene changes which mean a higher chance of having a child with a genetic condition. Genetic carrier screening can identify whether you carry any of these gene changes that could cause a particular condition in any of your children.

What is the prepair™ genetic carrier screen? What conditions are screened for?

prepair looks to see if you’re a carrier of cystic fibrosis (CF), fragile X syndrome (FXS) and spinal muscular atrophy (SMA). These are some of the most common inherited genetic conditions in the general population and have serious health consequences. You can read more about these conditions here.

Can carriers develop symptoms?

Carriers of CF and SMA are healthy and do not develop symptoms.
Some female FXS carriers may develop fertility problems and there is an increased chance of early menopause (before 40 years of age). Some male and a small number of female carriers of FXS develop a late-onset neurological condition which causes tremors and balance problems later in life which worsen with age.

Why should I consider prepair™ genetic carrier screening?

One in 20 people are carriers of at least one of these conditions. Our recent research has shown that about 90% of carriers have no family history of CF, FXS or SMA – this means carrier screening for these conditions is relevant to everyone.

Carrier screening is a personal choice. It is important to consider what a carrier result would mean for you and your family. Our research shows that most people use this information to inform their reproductive decision-making and planning. Some opt for genetic testing in pregnancy, others choose to conceive via IVF to avoid having a child with the condition, and some do not have further testing but use the information to help them prepare for the possibility of having a child with the genetic condition. 

At VCGS, we provide a complete service for people who choose to have carrier screening. Genetic counselling is available to all people having prepair. As we are not-for-profit, all proceeds from prepair tests go towards medical research at the Murdoch Children's Research Institute.

What does the test involve?

prepair is performed on blood or saliva samples and can be arranged through a doctor, genetic counsellor or midwife.

What will the test tell me?

The prepair test will tell you if you’re a carrier of CF, FXS and SMA. About one in 20 people will be a carrier of at least one of these conditions.

What if the test shows that I am a carrier?

If your test shows you have one copy of the gene change for CF or SMA, you’re a carrier of this condition. However, a couple can only have a child with CF or SMA if both parents are carriers of that condition. If you are a carrier, your partner will be offered testing. When both members of a couple are carriers of the condition there is a 25% chance of having a child with that condition for each pregnancy.

For FXS, it is only women who carry a gene change that have a greater chance of having a child with FXS. This means their partner does not need to have carrier testing. Female carriers of FXS have up to a 50% chance of having a child with FXS for each pregnancy they have.
If you receive a carrier result, you have the option of speaking to a genetic counsellor to discuss your results in detail.

How do I arrange the test?

Discuss prepair with your doctor, midwife or genetic counsellor and ask them to complete a prepair test request form for you.

Order a prepair saliva kit online by visiting https://www.vcgs.org.au/order. The test kit will be sent to your indicated address with a reply pre-paid return mailer; OR have your blood sample taken from one of our affiliated collection centers. Your result will be available in approximately two weeks. Results will be sent to the health professional who ordered your test.

When can the test be performed?

prepair is ideally performed before pregnancy and can also be performed in early pregnancy (<12 weeks gestation).

What if I need more information or want to discuss my result with an expert?

If you have any questions about the prepair test or about your specific result you can speak to an expert by contacting our VCGS screening genetic counselling team (03 9936 6402). Our genetic counsellors offer expert information and support to women who undergo prepair, and are on hand to answers questions and discuss options. We can liaise with laboratory scientists, doctors, support organisations and hospital and community services on your behalf.

Where can I found out more about prepair™?

View this video to find out more about how prepair works, or visit our website.