Overview

The Victorian Clinical Genetics Services (VCGS) offers a comprehensive range of tests for genetic heart disorders which includes cardiomyopathy, arrhythmia, aortopathies and congenital heart disease.

Our approach uses multi-gene 'panels' that are tiered to assess genes that are known to cause specific heart condition. With the option of choosing from our targeted panels, creating customised panels or utilising the comprehensive panel, testing can be personalised and made more affordable.

Our panels provide 100% sequence coverage of the coding region which means there are no gaps in our sequence analysis.

What is this test?

Cardiac genetics
Heart disorders affect the normal function of both the heart muscle and the large blood vessels that carry blood to and from the heart. These disorders can run in families, whilst others may be isolated to a single-family member and are caused by environmental factors such as trauma and infection.

Genetic heart disorders are caused by gene changes that affect the development of the heart and blood vessels. Identification of genetic causes of cardiac disorders can be life saving. It is also important for family members as they may also be at risk of developing heart problems. Establishing a genetic cause for heart conditions can direct and target patient testing, management and surveillance.

How does cardiac panel testing work?
At VCGS, gene testing for genetic heart disorders is performed in ‘panels’ using a technology called Next Generation Sequencing (NGS). Our panels are grouped into genes that are known to cause related heart conditions.

NGS is used to read the genetic content (DNA) to identify changes in the DNA sequence that are known to cause genetic heart conditions. These DNA changes, known as mutations or variants can be benign (not associated with disease), pathogenic (can cause a cardiac condition) or their significance may not yet be known.

VCGS uses a team of clinical geneticists, genetic counsellors and clinical scientists to determine the significance of these variants.

What conditions does this test look for?

Our cardiac disorder panels fall into four major categories: aortopathy, arrhythmias, cardiomyopathies and congenital disorders with some categories being further tiered based on clinical indication. VCGS also performs all follow-up testing including prenatal analysis.

Aortopathy are conditions that affect the aorta, the main artery supplying the heart with oxygenated blood. The aorta can become enlarged or weakened, which disrupts blood flow.

Arrhythmias are disorders where the rate or rhythm of the heartbeat is irregular. The heart can beat too fast (tachycardia), too slow (bradycardia) or with an irregular rhythm.

Cardiomyopathies are disorders of the heart muscle, which becomes weakened, stretched, or has other structural problems. There are many types of cardiomyopathy which can be caused by genetic variants in a number of genes.

Congenital cardiac disorders are structural changes in the heart that are present at birth. Congenital heart disorders are the most common anomaly observed at birth and can be life threatening.

VCGS also offers a comprehensive inherited heart disease panel which combines the Cardiomyopathy, Arrhythmia and Aortopathy panels in instances where the cause of the cardiac condition is unknown or in cases of sudden and unexplained cardiac failure.

Aortopathy

Aortopathy are conditions that affect the aorta, the main artery supplying the heart with oxygenated blood. The aorta can become enlarged or weakened, which disrupts blood flow. Aortic dilation can be a key feature in genetic dosorders, such as Marfan, Loeys-Dietz, vascular Ehlers-Danlos, aneurysm-osteoarthritis and TAAD.

View Test & Specification requirements

Arrhythmia

Arrhythmia are disorders where the rate or rhthym of the heartbeat is irregular. The heart can beat too fast (tachycardia), too slow (bradycardia), or with an irregular rhythm. The Arrhythmia full panel tests genes known to be associated with arrhythmias. VCGS provides tiered options that contain genes specific to subsets of arrhythmia conditions.

View Test & Specification requirements

The Brugada syndrome is a disorder that is associated with ventricular fibrillation that can lead to cardiac arrest.

View Test & Specification requirements

CPVT is characterised by episodic syncope that occurs during exercise or at times of acute emotion. The underlying cause of these episodes is the onset of fast ventricular tachycardia.

View Test & Specification requirements

Familial atrial fibrillation is characterised by uncoordinated electrical activity in the atria, which causes a fast and irregular heartbeat.

View Test & Specification requirements

LongQT is characterised by abnormal QT intervals on ECG and ventricular tachycardia. A long QT interval can upset the careful timing of the heartbeat and trigger dangerous heart rhythms.

View Test & Specification requirements

ShortQT is characterised by abnormal QT intervals on ECG and ventricular fibrillation. A short QT interval can upset the careful timing of the heartbeat and trigger dangerous heart rhythms.

View Test & Specification requirements

Cardiomyopathy

ARVC is characteried by progressive fibrofatty replacement of the myocardium in the right ventricle which can lead to sudden cadiac failure.

View Test & Specification requirements

Cardiomyopathies are disorders of the heart muscle, which becomes weakened, stretched, or has other structural problems. There are many types of cardiomyopathy which can be caused by genetic variants in a number of genes. The full cardiomyopathy panel assessed all the genes known to associated with inherited cardiomyopathies.

View Test & Specification requirements

Dilated cardiomyopathy (DCM) is characterised by left ventricular enlargement and systolic dysfunction which results in a reduction in the myocardial force of contraction causing heart failure, arrhythmia and thromboembolic disease.

View Test & Specification requirements

Hypertrophic cardiomyopathy (HCM) is typically defined by the presence of unexplained left ventricular hypertrophy (wall thickness). This can lead to progressive heart failure and sudden death.

View Test & Specification requirements

Is characterised by an excess of muscle bands called trabeculations in the left ventricle, giving it a spongy appearance, which can lead to heart failure or arrhythmias.

View Test & Specification requirements

Comprehensive Cardiac Panel

Congenital Cardiac Disorders

Congenital cardiac disorders are structural changes in the heart that are present at birth. Congenital heart disorders are the most common anomaly observed at birth and can be life threatening.

View Test & Specification requirements

Supplementary Cardiac Testing

Cascade testing is performed when a familial variant is known using Sanger sequencing or MLPA.

View Test & Specification requirements

VCGS provides the flexibility to customise the genes to be targetted. Up to 5 genes that are contained within the Comprehensive Cardiac and Congenital Cardiac panels can be included in a custom panel.

View Test & Specification requirements

MLPA screening is performed when panel testing is negative and a copy number variant is suspected.

View Test & Specification requirements

MLPA screening is performed when panel testing is negative and a copy number variant is suspected. For LongQT referrals, all genes listed are tested, for Brugada syndrome only SCN5A is tested.

View Test & Specification requirements

This test is performed when we are validating a variant found in the research setting or a variant was found in an external laboratory and familial cascade testing is required.

View Test & Specification requirements

May be required for some familial variants.

View Test & Specification requirements

If prenatal testing is being considered, please contact the laboratory.

View Test & Specification requirements

VCGS provides the option to expand the analysis if a pathogenic variant was not found in the selected panel. Contact our laboratory to discuss these options.

View Test & Specification requirements
How do I arrange a test?

Panel testing can be arranged through your heart specialist, specialist cardiac genetics clinic or general genetics clinic. A request from signed by your referring doctor and a completed patient consent form are required.Your doctor will discuss with you the benefits and risks of testing. Based on your clinical presentation, they will select the most appropriate test panel.

Testing is usually performed on a blood sample, however other tissue may be used if blood is not available (i.e. if patient is deceased).

Testing typically takes 3-4 months.

Frequently asked questions

How much does cardiac panel testing cost?

Cardiac panel testing is tiered to provide flexible and cost effort testing. In cases where an gene variant has not been found, expanding the analysis to include additional panels can be performed at reasonable costs.

Once a variant has been identified in the family, relatives can be tested for that specific variant at a much lower cost.

There is no government rebate or private health coverage for cardiac disorder panel testing.

Please contact us for our full price list on vcgs@vcgs.org.au

How will I get my results?

Panel testing typically takes 3-4 months and your results will be reported to your referring doctor. They will discuss any significant results with you and may refer you to a genetic counsellor if appropriate.

What do my results mean?

Once your sample has been tested, a team of experts review any DNA changes or variants found. The team will determine the significance of any variants, using all the available published scientific literature.

Variants fall into a number of categories:

Class 5: Pathogenic Variant:
Pathogenic variants are considered disease-causing
  • At-risk unaffected relatives can be offered predictive gene testing.
  • Other affected relatives can be offered confirmatory testing.
  • Prenatal diagnosis for the pathogenic variant is possible.
Class 4: Likely pathogenic variant:
The level of evidence that likely pathogenic variants are disease-causing is very high.
  • At-risk unaffected relatives can be offered gene testing in conjunction with clinical screening.
  • Other affected relatives can be offered confirmatory testing.
  • The variant may be considered for use in prenatal diagnosis after detailed discussion with a clinical geneticist or genetic counsellor.
Class 3A: Variant(s) of unknown significance with high clinical significance: VUS with high clinical significance are variants that have evidence to suggest they are pathogenic but there is not enough information to classify them as class 4.
  • Class 3A variants cannot be used for predictive testing or prenatal diagnosis.
  • Co-segregation studies in affected relatives, or testing to determine if the variant is de-novo is strongly recommended as these studies may provide additional evidence to clarify the pathogenicity of class 3A variants.
  • These variants may be re-classified based on new information; for example, family and/or functional studies (if performed).
Class 3B: Variant(s) of unknown significance: Class 3B VUS are variants for which there is insufficient evidence to classify the variant as either disease causing or likely benign.
  • Class 3B variants cannot be used for predictive testing or prenatal diagnosis.
  • In selected families, co-segregation studies in affected relatives may help to clarify pathogenicity of a class 3 VUS.
Class 3C: Variant(s) of unknown significance with low clinical significance: Class 3C VUS are variant(s) for which the evidence suggests they are likely to be benign.
  • Class 3C variants cannot be used for predictive testing or prenatal diagnosis.
No variant of significance was found.
  • Reanalysis options may be considered if the family history strongly indicates a genetic cause.

I carry a pathogenic variant but I have no symptoms. What does this mean?

If you carry a pathogenic variant (gene change that causes a heart condition) but have no symptoms, you have an increased risk of developing a heart condition. This risk will vary depending on the type of variant you have and the type of cardiac condition. It is recommended that you have regular check ups with your doctor.

It also means that you have a 50% chance of passing this variant to any biological child. VCGS can provide support when discussing genetic results with family members.

What happens to my genetic information?

Cardiac panel testing generates a large amount of genetic information. Access to and storage of genetic information is strictly governed by national laboratory and health privacy guidelines. You will be required to sign a consent form for panel testing and this form describes how your information can be used.