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22 January 2007
The grandfather had lived to age 76, but by age 43 his grandson had already had five heart attacks. In the old man's generation the average age of death was just 37. According to on-line science magazine 'Science in Africa', while speaking at the recent 'Beyond Race' conference held in Cape Town, Groote Schuur Hospital lipidology authority Professor David Marais used this as a typical example of a 'family tree' affected by a condition that strikes the Afrikaans community with a particular vengeance.
While as many as 6,8 million South Africans suffer from genetically high cholesterol levels - which are determined by both hereditary and dietary factors - Professor Marais says the Afrikaans community is most at risk of familial hypercholesterolaemia (FH), where high cholesterol levels are the result of specific genetic defects. A specialist physician and head of the division of lipidology in Groote Schuur's Department of Medicine, Marais said FH had been diagnosed in patients from several ancestral lines, and that while Indian and Jewish communities were also at risk, the highest prevalence was in Afrikaans people.
According to the Heart and Stroke Foundation SA, it is estimated that 1 in 75 individuals in these three communities may be affected, people who often have a family history of premature heart disease - heart attack or sudden death in men before the age of 55 years and before the age of 65 in women. The reason for this condition being so prevalent among the Afrikaans is because the disease arrived in South Africa with a Huguenot couple, and spread from them, a phenomenon known as the "founder effect" in genetics.
A consequence of FH is often the early development of problems like atherosclerosis, or narrowing of the arteries, which translates directly into heart problems.
Recognising atherosclerosis, pancreatitits and other rare disorders, was important for genetic counselling as well as for public health planning, said Marais, who, while stressing that inherited metabolic disorders "certainly" had impacts for high-risk communities, said "preventive treatment could be effective".
Although the average age of the first heart attack for sufferers of FH was 45 years, whatever the ethnic group, the disturbing fact among Afrikaners is that it's not just the adults being affected. Marais said children "as young as six or seven" were undergoing heart bypass surgery.
He said the disease affected people quite young, and that those in the Afrikaans community suffering from the disease were primarily affected by the FH2 variant of the responsible gene, which translated into heart disease at a much younger age.
And it appears that there are various mutations of familial hypercholesterolaemia. From studies at his Cape Town clinic Professor Marais said the CT2 mutation points to a predominantly coloured group which appeared to come from around Mossel Bay, while another group could be linked to migrants from Eastern Europe. The French-Canadian mutation had been identified in Indian people too, and a Scandinavian defect had been found in several Afrikaans people. Among Afrikaans people in South Africa, about three mutations had been found to be responsible for two-thirds of cases.
Despite being the most severe examples, with the cost of an average heart bypass at R120 000 and an ordinary heart attack admission in the region of R30 000, treating heart disease can be expensive, although it needn't reach such dramatic stages. Marais turns the argument around: "The perception is that it's expensive to treat, but the reality is that often it is expensive to not treat. We need regional clinics with dietetic services, and this network of clinics should run in conjunction with a dedicated integrated national centre of expertise".
Treatment and diagnosis, he said, was hampered by "limited resources", competing healthcare pressures, a transitional population, limited public awareness as to the severity of the problem, along with the centralised clinics and little support.
So while genetic diseases translate directly into a major financial health burden for South Africa, the best people can do - especially the 'at risk' Afrikaans population - is to look after themselves.
Diets overly high in saturated fats (mainly found in animal meat and fat), cholesterol and kilojoules can increase cholesterol levels, which, when they clog up arteries and restrict the blood flow to the heart, are quite literally potential killers. You don't have to be Dr David Marais or any other specialist physician to know that fair amounts of exercise, stopping smoking and going easy on the alcohol is the cheapest and most effective start to managing a heart that arrived with its own set of challenges. The grandfather initially quite possibly didn't know he had the guilty gene, his 43 year-old son and victim of multiple heart attacks neither. Today, however, ignorance is no excuse
We have cardiologists and experts in this field ready to be interviewed and give any information needed to get this message across to your readers, as well as ordinary South Africans who have suffered from heart disease and are happy to share their stories.
FOR MORE INFORMATION CONTACT:
Michelle Kearney,
Project Director: Communications & Public Relations,
The Heart and Stroke Foundation SA
+27-21-447 4222 -
email: michelle@heartfoundation.co.za
**This article was written by CNN Africa Journalist 2006 Angus Begg
The Heart and Stroke Foundation SA
80% of westernised South Africans have raised blood cholesterol, of which 20% have levels that place them at high risk of developing heart disease.
What are the risk factors for high cholesterol?
- Genetics: family medical history and race.
- Age: between the ages of 20 and 65 years, total cholesterol levels may steadily increase, where after they decrease slightly in men and tend to plateau in women
- Gender: women have higher HDL cholesterol levels than men and so have less risk of developing heart disease than men. With menopause the LDL increases and their risk equals that of men.
Who should have their cholesterol tested?
Most people with high cholesterol feel perfectly healthy - there are usually no warning signs of high levels. The only way to find out is to test for it.
All adults should know their cholesterol level and have it tested at least once every 5 years. Those with a family history need to be tested more regularly. If your cholesterol levels are normal, you only need to test it again in a few years, but if it is high or you have a family history of high cholesterol or heart disease, have it checked regularly. Children don't need to have their levels tested unless they have a family history.
An example of a major gene defect - familial hypercholesterolaemia
The major gene defect prominent in South Africa is known as familial hypercholesterolaemia (FH). It is inherited in a dominant fashion which means that the presence of only a single FH gene from one affected parent can produce the condition in the child who inherits it - that is, in an average of 50% of the offspring.
In a person with the gene for FH, cholesterol levels, mainly LDL cholesterol, are raised from birth making early diagnosis possible. However, clinical disease usually shows itself in adulthood.
As many as 85% of affected men have clinical CAD by the age of 60 years while women follow on a decade later. Significant numbers show severe symptoms in their thirties or forties while a few affected individuals are healthy until their seventies or eighties.
The condition is surprisingly common amongst the Afrikaans population, with an incidence of around one in 75. This is because the disease arrived in South Africa with one Huguenot couple and spread from them. This phenomenon is known as the "founder effect" in genetics. The disease also occurs in all the other South African population groups with the lowest incidence in the black community.
Diagnosis can often be made clinically and from routine laboratory measurements, but molecular techniques now permit definite identification of affected individuals and, even more importantly, prenatal testing.
The genetic defect prevents LDL cholesterol from being effectively removed from the bloodstream by the LDL receptor. This also stimulates increased cholesterol synthesis in the body.
Much more rarely an individual inherits an FH gene from two affected parents. This is called the homozygous condition and is much more severe, with CAD generally present by the age of 20. Unlike the more common single gene, or heterozygous form, it cannot be effectively treated by means of drugs alone and requires the facilities of a specialised lipid clinic.
BIOCAREER
Local molecular biologist wins award for gene testing patent
17-August-2005 Cape Biotech
The National Research Foundation has awarded Dr Maritha Kotze R25 000 for developing and applying a patent on a genetic test for cardiovascular disease. The patent for a 'DNA based cardiovascular disease diagnostic assay' is the first test of its kind in South Africa. The test screens patients for a number of genetic risk factors for heart disease simultaneously, averting the need to conduct individual tests.
Dr Kotze, who is the Managing Director of Cape Town based molecular genetics laboratory Genecare Molecular Genetics, registered the patent with the help of the Medical Research Council (MRC) three years ago.
Dr Kotze has spent nearly 20 years researching familial hypercholestrolaemia (FH) and other genetic risk factors for heart disease. FH is a genetic condition affecting mainly Afrikaans, Indian and Jewish communities in South Africa and typically causes heart attacks in men who are in their 40s and women in their 60s. The DNA test screens for FH and other genetic risk factors that can be triggered into heart disease by lifestyle risk factors, if left untreated.
Dr Kotze has more than 20 years experience in routine genetic diagnostics and research in the field of Human Genetics. She has a PhD in human genetics and previously held the position of Associate Professor at the Faculty of Health Sciences of University of Stellenbosch. Her publications include more than 100 peer reviewed articles.
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