Carrier screening
Nine out of ten children born with CF are born into families with no known family history of the condition. To have a child with CF, both parents must be a carrier of the gene change that causes CF.
CF carrier screening services are available to help you and your partner find out whether you are among the one million Australians who carry the CF gene change.
If both parents are carriers of the CF gene change, then with each pregnancy there is a 25% risk of that child having CF. Being a CF carrier does not mean you have CF and carriers usually display no symptoms of CF.
What is CF carrier screening?
CF carrier screening is a genetic test that will help to identify if you have changes to the CF gene.
The test involves providing a blood or saliva sample and requires a referral from your GP, obstetrician or gynaecologist. There are around 2,000 gene changes that cause CF and a typical CF screening will identify the most common CF gene changes in Australia. However, there is still a small risk that you may be a carrier of a rare CF gene change.
If you have a family history of CF, it is important to tell your GP, obstetrician or gynaecologist before providing your sample for screening. This will ensure that you are being tested for the most common CF gene changes as well as the specific gene change relevant to your family.
For people with a close relative who has CF (first cousins once-removed or closer), the cost of the test may be covered by Medicare. Speak to your doctor to check your eligibility for the rebate. If you have no family history of CF, you can pay for the test yourself (expect to pay at least $150).
CF carrier screening is only available to those 18 years and over and is the only way to find out if you are a carrier of the CF gene change. The test can be ordered prior to pregnancy or early in a pregnancy.
For more information on genetic testing:
Could you be a carrier?
An estimated 1 in 25 Australians carry the gene changes that can cause CF, and most people are unaware if they are a carrier.
Making the decision to know your CF carrier status through genetic testing is a choice only you can make. Knowing whether you are a carrier can help inform you of all of your reproductive options.
The earlier you make a decision about knowing your CF carrier status the more options you will have. You can discuss your CF carrier screening options with your GP, obstetrician or a genetic counsellor.
Is it better to know my CF carrier status?
Everyone’s reason for wanting or not wanting to know their CF carrier status will be different. What is important is that you feel you have made an informed choice that suits your particular situation and needs.
However, the more open people are about the existence of CF in the family and the availability of testing like CF carrier screening, the more informed people can be when they make their own choices about finding out their CF carrier status when they are ready.
CF Community Care supports individuals having an opportunity to make informed life and reproductive choices as a result of CF carrier screening.
Some parents are interested in finding out the carrier status of their children who do not have CF. The Human Genetics Society of Australasia guidelines on genetic counselling recommend that minors should only have carrier testing when the results will inform their health management in the immediate future.
Newborn screening (heel prick test) and CF carrier screening are different. Newborn screening will generally not identify a child’s CF carrier status.
Should you talk to a genetic counsellor?
Genetic counsellors are accredited health professionals who can talk about your family history, explain your test options, and discuss what your test results mean to help you and your family make informed decisions.
Some genetic testing services, such as Victorian Clinical Genetics Services, offer free genetic counselling if you are considering taking a carrier screening test. Genetic counselling can be done by appointment in a clinic or by phone.
If you decide to be tested
Visit your healthcare provider – Let your healthcare provider (such as your family doctor or obstetrician) know that you wish to have genetic carrier screening. Your healthcare provider will need to complete a referral to a service that does CF carrier screening. You can order a saliva sample kit online that can be mailed to you.
Contact a screening service – Services such as Victorian Clinical Genetics Services will organise a saliva sample kit to be mailed to you or recommend a pathology service who can do the test.
Take the test – It is recommended that the female partner is tested first. If you have a family history of CF, Medicare and private health insurance may subsidise the cost of carrier screening.
Visit your healthcare provider to get your results – Typically your results will be communicated to your healthcare provider within 2-4 weeks. They will inform you if you carry the CF gene change.
If the test shows you are a carrier – We recommend that you discuss your result with a genetic counsellor. Some carrier screening services provide genetic counselling as part of their service. Depending on your result, your healthcare provider or a genetic counsellor will discuss carrier testing for your partner also. If the results show that you and your partner are both carriers of CF, a genetic counsellor can help you to consider your options.
Carrier screening resources