Spotlight on Sudden Cardiac Death

It is estimated that ~60 young Australians (1-35 years of age) die from unexplained sudden cardiac death each year.

The estimated “cost” to society of each sudden death is ~$3 million and preventing just 10% of these unexplained sudden deaths in Australia would save ~$18 million per annum.

The sudden death of a child or young adult has a devastating impact on families, friends, and the wider community.

A new electrical test developed by the Victor Chang Cardiac Research Institute, in collaboration with the Garvan Institute of Medical Research, St Vincent’s Hospital, Sydney, Vanderbilt University Medical Centre, and the University of Oxford, is changing that.

Inherited arrhythmia disorders are found in more than half of all unexplained cases of sudden cardiac death in young people, and many of those who die won’t know they have a heart condition until it’s too late.

The test assesses variants in ion channel genes associated with Long QT syndrome – an inherited heart disorder -  but it can easily be adapted to test other ion channel genes – and not just ones associated with sudden cardiac arrest but a wide range of other diseases spanning neurological, kidney, and muscle disorders.

The results are now being adopted by diagnostic gene testing laboratories to assist with gene variant classification; results which are then passed on to clinicians to help manage their patients.

It is hoped that within the next five years, anyone considered at risk of these inherited heart disorders will be able to be screened and find out if their variant is dangerous. By doing so the patient will be able to make lifestyle changes, as well as taking beta-blockers or even using a defibrillator to reduce their risk of having a sudden cardiac arrest.

This will reduce the number of cardiac arrests and deaths caused by inherited heart genetic disorders.

Looking ahead, the research can be adapted to assess any of the approximate 400 different ion channel genes in the human genome which are associated with a wide range of neural disorders, muscle and kidney problems.

Research led by Professor Jamie Vandenberg and published in the American Journal of Human Genetics revealed the new test can now screen hundreds of gene mutations at a time through high throughput technology housed in the Institute’s Innovation Centre.

Expanding the Institute’s Reach and Beyond

As a result of this work, the Institute has trained three honours students and two PhD students to use state-of-the-art technology.

They have also established new collaborations with all the major diagnostic gene testing units in Australia (including Victoria Clinical Genetic Services, Queensland Genomics Research Centre, and NSW Health Pathology) as well as with international research consortia (including the LQTS-Next consortium based in Europe) and major commercial Gene Testing Companies (including In Vitae and Ambry Genetics).

The team is now classifying all known variants to determine which are likely to be dangerous and has begun uploading the findings to a giant genetic database that is accessible to clinicians around the world.