Researchers have developed a new electrical test that can screen hundreds of gene mutations to pinpoint the exact mutations that are harmful to the heart for those suffering from inherited heart disorders syndromes, which can cause sudden death.
The new research from the Victor Chang Cardiac Research Institute will allow families to discover if they are carrying genetic mutations that cause sudden cardiac arrest—a condition that kills nine out of 10 victims.
The breakthrough seeks to improve the accuracy and precision of genetic testing that has profound implications for inherited heart disorders and a wide range of other neurological conditions, and muscle and kidney diseases.
“It’s primarily young people with otherwise healthy hearts that die from these inherited heart disorders and even though that number is small, the consequences are long-lasting,” says Professor Jamie Vandenberg, who led the research published in two back-to-back papers in the American Journal of Human Genetics. “When a person dies young, in the prime of their life, it’s a lot more than just the death of one individual. The impact is felt on the family and their friends and that lasts forever.”
In the first study, researchers developed a fast and accurate electrical test that assesses variants in an ion channel gene that causes an inherited heart arrhythmia condition called Long QT syndrome type 2. They’re now classifying all known variants in this gene to determine which are benign and which are dangerous and will be uploading the findings to a giant genetic database that will be accessible to clinicians the world over.
In the second paper, Vandenberg and his team collaborated with Brett Kroncke, PhD, at Vanderbilt University Medical Centre to develop a new method based on high throughput genome sequencing technology. This will enable them to assess the impact of every possible missense variant in KCNH2, which amounts to approximately 22,000 variants, within one to two years.
Fellow author Chai-Ann Ng, PhD, of the Victor Chang Cardiac Research Institute, says that being able to identify these dangerous mutations will prevent people from dying from sudden cardiac arrest and ensure more people are treated for this life-threatening disorder.
“If you can isolate the mutation and identify those at risk, there are lifestyle changes people can make, as well as taking beta-blockers or even using a defibrillator. Family members can also get themselves tested too,” says Ng. “Genetic sequencing has revealed that all of us contain a vast array of genetic variants, but we have not always been able to pinpoint if these variants are dangerous or not, only that they are different.”
Ng added: “So when genes are currently tested, the clinical genetics lab may tell the patient, there’s a variant, but we don’t know whether it raises your risk of cardiac arrest. That creates a huge amount of anxiety not just for the patient but also for the rest of the family who may also have inherited the mutation. We can now remove that uncertainty which is a big development.”
Featured image: Professor Jamie Vandenberg operating the Syncropatch at the Victor Chang Cardiac Research Institute. Photo: Victor Chang Cardiac Research Institute