Genetic testing

What are genes?

Genes contain the instructions for making proteins, which are the building blocks of the cells that make up your body. You have a complete set of all your genes in each cell in your body.

What is genetic testing?

Genetic testing is when a lab checks your genes for variations or mutations. There are many variations found in genes, and only some of them are important. Some types of genetic variations can cause medical problems or increase the likelihood of developing certain diseases in the future.

The testing is only the first part. The important part is understanding what the test results mean. For that, you should talk to a doctor or genetic counsellor.

When might I consider genetic testing?

You might consider having genetic testing if:

• you have a newborn baby — a simple blood test can detect some rare genetic conditions
• you are early in pregnancy — non-invasive prenatal testing can determine the chance your baby has a genetic condition such as Down syndrome. Genetic carrier screening can also be done which tests for a wider variety of genetic conditions, including cystic fibrosis, Fragile X syndrome and spinal muscular atrophy (the cost of this testing is expected to be covered by Medicare starting in 2023)
• there is a condition that is in your family, and you’re worried that you or your children will develop it
• you have a child who is severely affected by problems with their growth, their development or their health
• you and your partner are related by blood
• you or your partner have been exposed to chemicals, medicines or radiation that could cause genetic abnormalities

Genetic testing can give you important information if you are planning a family or if you, or someone you care for, has a genetic disorder. But before you start, there are plenty of issues for you to think about, including where to go if you choose to do a test.

How is the test taken?

Most genetic tests are blood tests. It is also possible to do tests on a sample taken from the inside of your mouth (known as a buccal smear) or from your saliva. These are easy and safe.

If you’re pregnant, prenatal testing may include a blood test, chorionic villus sampling (CVS) or amniocentesis. Visit the Pregnancy, Birth and Baby website for more information on prenatal screening.

It’s also possible to order tests online without seeing a doctor. The National Health and Medical Research Council warns people to be cautious of this.

How much do genetic tests cost?

The cost varies enormously. Before you start, ask your doctor or genetic counsellor how much the tests cost and whether or not they are covered at all by Medicare. Tests ordered privately online are not covered by Medicare.

What are the benefits of genetic testing?

The main benefit is knowledge: if you have a genetic test, you can get advice about what the result means. If you have a condition that might have a genetic basis, you will understand it more clearly.

If you’re having a baby, it helps you plan how to manage your pregnancy, birth and the life that follows. It can also help if you’re wondering about having a termination.

For some people, testing can get rid of some of the uncertainty around their health, for example, fears they may be a genetic carrier of a particular disorder.

If you feel well but are worried about having a condition that is in your family, genetic testing can prompt you into action to reduce your chances of getting ill. This could be through lifestyle changes, such as diet and exercise, or by having more frequent screening tests for the condition.

What are the risks of genetic testing?

Some people face discrimination at work if they are known to have a genetic mutation.

If you have any genetic tests, you may need to declare them for any life insurance or income protection. If the tests identify a gene variant that increases your risk of disease, that might make it hard or impossible for you to get insurance.

Some of the companies that you can order tests from online are based overseas. They might be less careful about privacy than Australian companies. Ordering tests from these companies has a risk that your private information could become available to others.

Is genetic testing always accurate?

Genetic testing is not always accurate. If you find that you have a variation to a gene, that gives a clue. But it doesn’t tell you how much you will be affected by the abnormal gene. Some people will be severely affected by an abnormal gene, while others will not be affected at all.

Also, testing for genes is complex and it can be hard to tell what minor changes in a gene mean.

What is genetic counselling?

The aim of genetic counselling is to give you information and support if you are considering having genetic testing. Genetic counsellors receive specialised training to provide this service.

Genetic counsellors can:

• advise you about your or your children’s risk of carrying a particular condition
• explore the potential impact that genetic testing results might have on you and your family
• advise you about family planning options in the context of your genetic history
• arrange genetic testing

Genetic counsellors can help in many different situations, including if you are:

• planning a pregnancy
• deciding about prenatal testing
• interested in finding out about your future risk of developing a disease

For more information about genetic counselling before or during pregnancy, visit Pregnancy, Birth and Baby’s page about genetic counselling.

What should I consider before having a genetic test?

Should I have a genetic test?

That decision is entirely up to you. There is no right or wrong answer. Talk to family and friends you trust. You can talk to your doctor or to a genetic counsellor. Take your time.

Talk to a doctor or genetic counsellor

It’s best to see your doctor or a genetic counsellor if you’re thinking about having a test. That way, you can talk through the implications of having the test. And if you go ahead with it, you can get some good advice about what the results mean.

Talk to your family about genetic testing

If you have a genetic test, you might find out things you wanted to find out, but you might also find out things you didn’t want to know. Your relatives might want to know everything, or they might want to know nothing.

The best way is to talk to them before you have any test, so you understand their point of view