Information on Genetic Testing

What is Genetic Testing?

Genetic testing looks for specific changes (variants) in a person’s genes. Some gene changes (variants) can be responsible for causing cardiomyopathy.

Genetic testing can be used to try and identify the specific gene variant causing a person’s cardiomyopathy.

Types of Genetic Testing

The type of genetic testing you can be offered depends on whether you have symptoms or a diagnosis of a cardiomyopathy, or if you are an at-risk family member.

It is important to speak to a genetic counsellor before undergoing any genetic testing. Your GP can refer you to a clinical genetic service or a specialised cardiac genetic service.

If you have symptoms of a heart condition, and your health care team recommends genetic testing to find a genetic cause of your heart condition, you may be offered diagnostic genetic testing.

Diagnostic genetic testing aims to identify a genetic cause for your heart condition.

Diagnostic genetic testing looks closely at a targeted number of different genes that have known association with inherited heart conditions. The genes that are looked at will depend on what cardiomyopathy you have been diagnosed with.

There are three possible outcomes from this type of genetic testing:

Number 1

Gene variant is identified
(positive result)

A genetic cause for your cardiomyopathy is identified. A positive result may help guide clinical management or confirm the current approach. This result also provides an opportunity for genetic testing of other family members.

Number 2

Gene variant is NOT identified
(negative result)

Sometimes when genetic testing is performed, a genetic cause for cardiomyopathy is not found. Not finding a genetic change can mean one of three things:

  1. The genetic change causing your cardiomyopathy is not located in one of the genes that was included in the test. 
  2. The technology used to perform the genetic test may not be capable of identifying the genetic change responsible for your cardiomyopathy.
  3. Your cardiomyopathy may not have a genetic cause.

Further research may be needed in order to locate the genetic change responsible. 

Number 3

Variant of Uncertain Significance (VUS)
(Uncertain result)

Sometimes a genetic change may be identified through diagnostic genetic testing, however the impact of this genetic change is not yet fully understood. This change could be the cause of cardiomyopathy, or it could be a harmless genetic variant. Through ongoing research, regular reassessment, and collaboration with other scientists around the world, this result will eventually become understood as either disease-causing, or harmless. This process may take years.

Cascade genetic testing can be used in family members when a gene change (variant) has already been identified as the cause of the heart condition in the family. Cascade genetic testing checks whether or not you have inherited the gene variant identified in your family.

There are two possible results from this type of genetic testing:

Number 1

Gene variant is identified
(positive result)

A positive result means you do carry the gene change (variant) responsible for the cardiomyopathy in your family. This means that you may have developed, or are at risk of developing, the same cardiomyopathy in your family. Your children will have a 1 in 2 (50% chance) of inheriting the gene variant from you.

It is essential that you see a cardiologist to have your heart checked if you receive a positive result.

It is important to note that not everyone in a family who carries the gene change (variant) will have the same severity of disease. This can only be determined through imaging and testing by a cardiologist in regular clinical screening.

Number 2

Gene variant is NOT identified
(negative result)

A negative result means you do not carry the gene change (variant) and are not at risk of developing the cardiomyopathy in your family. This also means that you can not pass the gene variant on to your children, and it cannot skip a generation.

It is likely you will no longer be required to attend regular clinical screening after receiving a negative result.

Looking for more information?

For more information about genetics try the Centre for Genetics Education