Director: Nutrition and education at the Heart Foundation, Shân Biesman-Simons:
The Heart Foundation encourages everyone to become aware of his or her individual risk for heart disease. Factors affecting risk include lifestyle, medical conditions and of course genetic predisposition. The Heart Foundation believes genetic testing is a powerful diagnostic tool. This is because many people do not fall into 'the at risk' category after conventional screenings, and it’s only as a result of specific genetic testing that they realise the importance of making the appropriate lifestyle modifications in order to avoid becoming a statistic.”

Dr Maritha Kotze, a geneticist at Genecare Molecular Genetics (Pty) Ltd. in Cape Town, states that a comprehensive Cardiovascular Genetic Screen, covered by most medical aids in South Africa, is now available to improve patient care. Genetic testing is useful to distinguish high-risk individuals requiring life-long medication from those at increased risk of CVD as a consequence of less severe gene-environment interactions that can be treated successfully by dietary and lifestyle changes. Individuals with normal or raised serum cholesterol levels with or without other CVD risk factors (e.g. family history of CVD, hypertension, diabetes and/or obesity) will benefit from genetic testing, provided that this is accompanied by the implementation of recommended nutrition and lifestyle changes.

The multi-gene CVD test includes two separate DNA-based strip assays that allow the simultaneous analysis of multiple mutations in a single reaction. The first test option includes eight mutations in the low-density receptor (LDLR) gene, which accounts for FH in the majority of affected South Africans. The second test option performed in conjunction with lifestyle and dietary assessments includes twelve mutations of relatively low expression in ten different genes implicated in the development of CVD. <BR><BR>
The genetic testing procedure begins with a doctor taking a cheek swab or blood sample from a patient considered to be at risk based on the medical history, and sending it for testing to the laboratory. The results are sent back to the doctor, and based on the diagnosis, is accompanied by a lifestyle and dietary plan for the patient. Knowledge that the modest effect of a mutation in a low-risk environment may translate into a major effect in a high-risk environment empowers patients to take responsibility for their health.

Once the patient has contemplated the impact of the genetic and lifestyle assessment they are able to better evaluate their current health status and visualise their health goals. As patients begin to understand that their co-operation is the key to sustained health it becomes easier to make the decision to pro-actively follow the action plan outlined in the genetic test report. Progress needs to be monitored on a regular basis by the primary care physician or supporting dietitian. Re-evaluation is recommended after a period of approximately three months, depending on the health status or severity of a chronic disorder. The realisation that the genetic and lifestyle information obtained can also be extrapolated to the children in the family may lead to a combined effort to make the recommended lifestyle changes.

Clinical application

Dr Heloise Avenant was one of the first general practitioners who started to use the information obtained from genetic testing performed at Genecare as an integral part of patient care. Based on initial successes, she founded a new company called Blueprinthealth in May 2005 to develop a computerised lifestyle intervention program for monitoring of patient compliance. According to Avenant, “genetic testing provides a sound basis for proactive long term planning to invest in one’s health, the most valuable asset of any person. People need to stay motivated, which is why it is so useful to have ongoing face-to-face contact with a health professional”. Reversing entrenched habits that have developed over a lifetime is difficult, and rates of compliance are often low”, says Avenant. “We as healthcare practitioners will have to emphasize the fact that preventive care pays, both in terms of cost and quality of life.”

Many dietitians in South Africa have also experienced that genetic testing linked to nutrition and lifestyle intervention programs support their efforts in facilitating change. Cape Town based registered dietitian Annelie Smith says genetics has boosted the field of nutritional therapy, providing a much-needed health tool. “One patient suffered from elevated triglycerides – blood fat – but was given cholesterol-lowering drugs, which were ineffective. He continued drinking alcohol, which is not advisable when triglyceride levels are high and only stopped when the real problem was identified.”

According to nutrition expert Dr Marjanne Senekal RD(SA), South Africa’s director on the newly established International Society for Nutrigenetics, the active participation of medical practitioners, dietitians and other health professionals makes genetic screening in South Africa an ethically responsible enterprise. “Genetic testing elsewhere often happens in isolation. But merely finding out whether one has a predisposition to a certain disease is not enough - proper counselling before the test are actually done as well as afterwards to provide the individual with appropriate prevention or treatment options, is needed. Genetic testing is not a quick fix.”

Dr Kotze agreed. “One of the benefits to health professionals who offer genetic testing at their practices is patient retention. Getting a test and discovering a likelihood of disease is not enough to make patients live healthily. The process needs to be managed by health professionals who will be able to monitor their habits more closely.”

Genecare has set up a growing network of health professionals that serves as a support base for the translation of genetic research into clinical practice. This HealthNet initiative (www.genecare.co.za) provides access to genetic counselling facilities in different regions of South Africa and support from Genecare’s expert consultants including a dietitian, pharmacologist and medical advisor. Internationally it is now accepted that because of the small number of registered genetic counsellors available, other health care professionals will need to help educate the public about the genetic basis of chronic disorders, the biochemical consequences, and the genetic testing options and procedures available.

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