Fifty years after South Africa performed the world’s first successful heart transplant, a woman from the Cape Flats has made another landmark medical discovery that could prevent hundreds of cardiac-related deaths every year.
After conducting a study for nearly 20 years, medical researchers have identified a new gene that is a major cause of sudden death among young people and athletes.
Maryam Fish, 30, of Lansdowne, led an all-female team of researchers at the University of Cape Town, along with Gasnat Shaboodien and Sarah Krause, who made the discovery with researchers from Italy.
The gene, called CDH2, is found in everyone, but a mutation causes a genetic disorder known as arrythmogenic right ventricle cardiomyopathy (ARVC), which increases the risk of heart disease and cardiac arrest.
Sudden cardiac death is estimated to hit more than five young people in South Africa daily, according to the Medical Research Council.
In under-35s an inherited form of disease of the heart muscle plays a prominent role in fatalities as a result of cardiac arrest.
“We sequenced all the genes in the human genome in two cousins who were affected,” said Fish, explaining that the cousins were identified after a 22-year-old relative died suddenly.
“We then looked for common variants and had a list of 13,000, which we narrowed down through a series of filtering criteria until we got the CDH2 variant, which was the most likely causal variant in this family.”
“(This) would allow us to identify members in families who may be carrying this disease and may be unaware of it. If we have a family member who we know has a mutation in this disease, we can have a look at the rest of their family, and if they are found to carry this mutation, they can be advised on behaviours to follow so they don’t develop the disease later in life,” Fish said.
This will make the early detection of many people affected by ARVC possible and see a reduction of cases of sudden death, Professor Peter Schwartz of the Italian Auxologico Institute of Milan said.
Often the diagnostic clinical signs of the disease become clear only after many years. If a subject with ARVC is a carrier of a mutation of the gene CDH2, it means that the subject is at a higher risk of cardiac disease, Schwartz said.
“Often people die and then the diagnosis is made. There are patients who have palpitations, who faint and the diagnosis is made and they are alive, but all too often the diagnosis is made afterwards.”
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