Genetic tests

Either a finger prick or a simple swab sample taken from the inside of your cheek. It is painless and can even be done yourself in the comfort of your home. It’s then sent off to the laboratory to be analysed. A process called the Polymerase Chain Reaction (PCR) is used, which copies the DNA of your genes many times over so that sufficient quantities of DNA are duplicated to analyse your genetic material. Unique DNA sequences are then identified in some of your genes. Certain changes (polymorphisms) in these genes have been studied in detail, with evidence that correlates these polymorphisms with an individual’s risk of developing certain chronic disease conditions or altered metabolic processes. Having identified the presence or absence of these polymorphisms, one is able to qualitatively assess particular areas of health risk related to the specific genes. To make a holistic assessment of health risks, environmental factors (diet and lifestyle) need to be considered in conjunction with the accompanying genetic profile.

DNA is a molecule containing all the instructions that make each of us completely unique. It is responsible for passing on genetic instructions from parents to their children. Your DNA is like a recipe book of instructions or a building plan for your body. Under a microscope, you will see that DNA looks like a twisting ladder, where four different chemicals called nucleotides, pair up to make the rungs of the ladder. Groups of nucleotides make up genes. Genes determine things like how tall you are and what colour your eyes are. DNA is stored in chromosomes. We inherit 23 chromosomes from our mother and 23 from our father. These chromosomes are completely random so cannot be predicted. That is why we all look and function differently.

So, here’s an interesting fact, did you know that genes can be switched on and off like a light bulb, based on dietary and lifestyle choices? Nutrigenomics helps us understand which genes we want to switch off or silence, as a way to improve our health and wellbeing. Sometimes we can’t switch them off entirely but like a dimmer for a light bulb we can reduce the strength of them. Genes provide the instruction for making proteins so if we switch off the instruction then the particular protein will be reduced or not made. This is how we can reduce the impact of genes that are particularly harmful.

The results of medical genetic testing is different as it can confirm or exclude a suspected genetic condition or assist with determining an individual’s risk of developing or passing on a genetic disorder. For example BRCA1 gene variation for breast cancer risk.

Medical genetic testing is usually accompanied with genetic counselling.

It will look at a variety of factors like your diet, with guidance on what to eat to manage your weight. Your overall health, personalised diet, supplement and lifestyle recommendations for optimal health. Your unique nutrition strategies to prevent diseases and manage oestrogen dominant disorders. It gives guidance on how to improve your sports performance and reduce risk of injury. It will give you a personalisation of your skincare regime and reduce the visible signs of aging to promote youthful skin. Lastly, it will help you find out more about your mental health and your genes impacting addiction, anxiety, depression and cognitive decline.

The most important benefit is a unique and targeted approach to diet and supplementation based on the individual’s genetic results. This provides clarity while removing the unnecessary information we are constantly bombarded with.

The guesswork is removed and one can be confident in knowing your own long term solutions for health. This includes being able to reduce the risk of chronic disease and promote optimum health.

Pharmacogenetics is the study of how a person’s genes affect the way a person responds to medications. It is being used to learn ahead of time what the best medication or dose of medication will be for an individual.

It helps to improve medication efficacy, decreasing length of treatment time, minimise adverse side effects and even reduce money spent on ineffective medications.

During the review of your genetic test results with a qualified healthcare practitioner, they will give you advice on which supplements you should be taking, and in what dosages. The gene results will guide this process and give valuable insight into dietary changes, supplement requirements and lifestyle changes to promote optimum health.

VitaGene has collaborated with two genetic test companies in South Africa to produce supplement guides for practitioners to assist them in making the best product recommendations for their patients.

Pharmacogenomics is the study of variances in your genetic code and how that affects the metabolism of the medications you may be taking. It helps to predict how fast or slowly your body may respond to certain medications, whether prescription or over-the-counter (OTC).

This test can determine how effective or safe the medicine will be in the individual and predict likely side effects. An Adverse Drug Reaction (ADR) is when individuals react unfavourably to a medication and an alternative medication needs to be prescribed. Medications are developed with the idea that each medication will work the same on each user. Personalised prescription medication is the new approach, which is why it is important that the prescribing doctor and pharmacist need to know which medicines will work best for each patient.

Other factors that may affect your medication prescription and how you respond to your medication include:

• Your age
• Your weight
• Your height
• Your kidney and liver function
• Other medications you may also be taking

Like other genetic tests, your genetic makeup does not change and you only need to do this test once. The test results are always available to refer to if you need to take OTC or prescribed medication.

No, your current medication will not affect your test results as this test measures how your genes will react to certain medications and does not take into consideration the actual medication taken.

Genetic counselling is based on medical genetic tests and provides individuals with information about genetic risks, benefits and limitations of genetic testing. The outcomes and management options are explored during the counselling session.

Genetic counsellors are trained healthcare professionals in the field of genetics and help to guide individuals on understanding the genetic test results and diagnosis as well as how these results will emotionally impact them and their family members. Genetic counsellors also provide support and guidance to assist family members by making informed decisions.

The genetic counsellor will discuss the following during the consultation:

• Your family medical history such as diagnosis of medical conditions and at what age
• Cause, inheritance and risk of know genetic conditions in your family affecting future pregnancies and your family
• Treatment options, management and preventative measures, if applicable
• Offer the option of genetic testing where appropriate
• Discuss the benefits and limitations of the genetic testing process
• Address any ethical concerns and queries
• Facilitation of the testing process with your referring doctor
• Communication of results and provide supportive care for at risk family members

• Carrier screening for autosomal recessive conditions such as Tay Sachs or cystic fibrosis
• Down syndrome
• Family history of certain cancers (breast, ovarian and colon cancer)