Researchers at the University of Cape Town’s Hatter institute for Cardiovascular Research in Africa (HICRA), with global collaboration, have identified a new gene that is a major cause of sudden death among young people. Although everyone has the CDH2 gene, a mutation of it causes the genetic disorder that leads to ARVC.
Breakthrough in medical science
This is the result of 20 years of international collaboration. The discovery was published on 9 March 2017 in Circulation: Cardiovascular Genetics. Researchers Maryam Fish, Gasnat Shaboodien and Sarah Kraus are the team who made the discovery.
“This is probably the biggest breakthrough in South African cardiology since Dr Chris Barnard’s first heart transplant,” said Professor Bongani Mayosi, dean of UCT’s Faculty of Health Sciences. “This discovery is a first in the world – on our soil – and will permit the diagnosis and possible treatment of heart muscle disease in the future.”
What is arrhythmogenic right ventricular cardiomyopathy (ARVC)?
It’s a rare inherited disease of the heart muscle that predisposes young people to cardiac arrest. The heart tissue is replaced by fatty and fibrous tissue, which causes rapid heart rhythm (cardiac arrhythmias) or rapid and erratic heart rhythm (ventricular fibrillation). The result is loss of consciousness and cardiac arrest. In the case of ventricular fibrillation, sudden death can occur in minutes if a device to shock the heart is not readily available.
According to the British Heart Foundation the cells of a healthy heart muscle are held together by proteins. If you have ARVC, it’s believed that these proteins did not develop properly and the proteins can’t keep the muscle cells together under stress, for example when your heart is beating harder or faster while exercising.
The symptoms of ARVC include heart palpitations, lightheadedness, fainting, swelling of the ankles or legs, shortness of breath and arrhythmias.
The CDH2 gene
Cardiac deaths claim more than five lives every day in South Africa. An inherited form of disease of the heart muscle (cardiomyopathy) in young people seems to have a strong link in the cause of sudden death related to cardiac disease.
Sevilla Football Club and Spanish international left wing Antonio Puerto died from ARVC in 2012, a few days after suffering from several cardiac arrests. He was just 22 years old.
English professional footballer Matt Gadsby collapsed on the pitch in 2006 and later died from ARVC – he was 27.
Another English footballer Fabrice Muamba retired in 2012 at the age of 23 after his heart stopped for 78 minutes after collapsing on the field.
The discovery of CDH2 will help make early detection of the disease possible.
“We learnt that it’s important if someone has the disease, intensive sports would be avoided. Athletes should be screened carefully. The disease can be treated, so that’s why it’s important to make diagnosis early,” said Professor Peter Schwartz of the Italian Auxologico Institute of Milan and the University of Pavia.
Hope for the future
“In the old days it used to take two to three years to screen on gene… Suddenly with technology you are able to screen 19 000 genes within a matter of hours. We called it genetics on steroids,” said researcher Gasnat Shaboodien.
“When pioneering medical researchers make discoveries such as this, it enables us to innovate to find easy ways to detect the gene or diagnose ARVC and find ways to prevent sudden death in young South Africans,” said Professor Glenda Gray, President and CEO of the South African Medical Research Council.
“This collaborative research is what we relentlessly seek to fund because it directly translates into finding ways to save lives in South Africa.”
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