Genetic testing
Genes hold the genetic information that our body needs to work. The genetic information is read like in an instruction manual. Genes give the instruction for our body so it can work.
Sometimes there is a change in a person’s gene, a bit like a spelling mistake in our instruction manual. Some changes don’t do anything. Other changes can cause disease.
Genetic testing looks closely at a person’s genes. This testing tries to find changes in a person’s genes that could cause a genetic condition.
When a young person passes away suddenly, genetic testing might be done to try and work out why they died on a blood sample from the deceased person which was collected at their postmortem.
In Australia, when a young person dies suddenly, a tube of blood will usually be stored during the postmortem that can be used for genetic testing.
Genetic testing can be done using a sample from a person’s blood or saliva.
Genetic testing for a person who has died is usually organised through a genetics service or a Genetic Heart Disease Clinic.
This is so the family can speak to a genetic counsellor.
From genetic testing, you will get one of three results. These are:
No changes were identified in the genes tested
Nothing found
A change that is believed to cause a genetic heart disease that can lead to sudden death is indentified
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Genetic testing is available to family members
A definite cause found
also called a “Variant of Uncertain Significance (VUS)", this means a change in the DNA has been identified, but there’s not enough evidence to know if it is causing a heart problem, or has no effect.
An uncertain result
Pickup rates of genetic testing
If no cause of death is identified at postmortem, genetic testing will identify a definite cause in 15-20% of people. This means that 1 in 5 people who have the test will find the gene change responsible.
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If the cause of death is identified at postmortem, the chance of finding the gene change depends on the condition. For example, in hypertrophic cardiomyopathy (HCM), the chance of finding a definite cause is up to 50%.
If a definite cause is found through genetic testing, first degree relatives (siblings, children, parents) can have a genetic test too. This is to see if they carry the same gene change and are at risk of developing the same heart condition.
If nothing is found on genetic testing or a variant of uncertain significance is identified, then genetic testing is not available to unaffected family members. For these family members, we recommend repeat heart checks with a cardiologist (every few years depending on your age).
If nothing is found on genetic testing then you can revisit and repeat genetic testing at a later date. Our knowledge about genetics is increasing every day, both as we discover new genes, and learn more about variants of uncertain significance which can help us work out whether they are causing a heart problem.
How do I organise genetic testing?
How can I find out if genetic testing will help my family?
Genetic testing needs to be organised by your local genetics service or a specialist genetic heart disease clinic. Genetic services are located at most major hospitals with outreach clinics available to those in rural and regional areas.
You will need to ask your GP for a referral to your local genetics service. To find your local service please visit the Centre for Genetics Education Website.
Genetic heart disease clinics are multidisciplinary clinics which specialise in clinical care and cardiac genetic testing. They are located in most capital cities and have strong connections with genetics services. A list of clinics can be found here