Sunday October 28, 2012
Secrets in your DNA
By DR NOR ASHIKIN MOKHTAR
Genetic profiling can help you decide what preventative measures you can take to reduce your genetic risk factors.
WHAT makes me different from you? It is the information encoded from the DNA in our genes, which determines every little physical and physiological detail of our bodies.
Genes give us the colour of our hair, eyes and skin, our body shape, our propensity to certain conditions and illnesses, and many more.
As we learn more about the intricacies woven into the human genome (the entire hereditary information of humans), we are beginning to have a better understanding of how certain genes play a role in the development of diseases.
Given these advances in genetic science, one of the most exciting developments to come out of it, is the potential to profile our individual DNA coding and to personalise medicine, as well as lifestyle advice, based on our genetic profile.
If our DNA is inherited and we are born with our genetic coding already in place, is there any point to genetic profiling? Isn’t it futile to try to “change” our genes?
There are two misconceptions inherent in this perception.
First, even though our genes – including genetic mutations – are inherited at birth, it does not mean that we are stuck with this fate for the rest of our lives.
Secondly, we are not trying to change our genes, but rather, influence a different outcome. Genetic testing allows us to identify genetic mutations present in our DNA that are related to the risk of developing certain diseases.
Therefore, by changing our behaviours and lifestyle practices as early as possible, we may be able to prevent or reduce the risk of these diseases.
Knowing our genes is not about trying to change the colour of our skin, but about minimising risks and maximising our health protential.
What is genetic profiling?
Earlier understanding of genes in medicine largely revolved around genetic mutations linked to hereditary diseases and certain medical conditions like sickle cell disease, Down syndrome, and other genetic diseases.
In this context, genetic tests were usually carried out on a foetus, newborn baby or on couples planning to have children, to help couples make family planning decisions if their future children do carry the risk of these diseases.
However, genetic medicine has gone beyond these functions, as scientists have now mapped out the entire human genome and identified the genetic components in many diseases, such as cancer, heart disease, diabetes and osteoporosis.
There are now laboratories that offer genetic profiling tests to identify these risk factors based on your genes.
Some genetic profiling laboratories can even predict your relative risk factors for glaucoma and blood-clotting disorders, such as deep vein thrombosis and pulmonary embolism.
With this information and advice from your doctor, you could take early action to prevent these conditions, or treat them early so that they do not reach a serious late stage.
How genetic profiling works
Genetic tests, such as those done for Down syndrome or hereditary diseases, usually look for specific changes in the individual’s chromosomes, DNA, or proteins, depending on the suspected disorder.
These tests are carried out in very specific situations, when one already suspects that there is a risk of the disease.
However, genetic profiling is different because you are not looking for a specific mutation, but for various mutations.
If you are an otherwise healthy person who may or may not have a family history of a certain disease, you would not know what specific mutation to look for – hence a genetic profiling panel is more appropriate for you.
Genetic profiling panels are a combination of various gene variations that are applicable to a bigger population, so that the profiling is more relevant to more people in the population.
It is very important to remember that genetic profiling can only tell you that you may have a predisposition, or increased risk, of a certain disease, but it does not mean that you will definitely develop that disease.
The whole idea of genetic profiling is to decide what preventative measures you can take to reduce your genetic risk factors, not to make you worry and despair about the fate of your health.
Your gene practitioner will be able to advise you on specific preventative health strategies to improve your long-term health.
Therefore, it is very important that your results be interpreted by an experienced and qualified doctor, who can then give you evidence-based advice on what preventative health strategies you need to take.
Personalised genetic medicine
What can you do with your genetic profiling results? Much has been said about personalised genetic medicine, which sounds very futuristic, although we are nowhere near science-fiction promises of a pill that can cure everything.
Personalised medicine uses information about your genes, proteins and environment, to prevent, diagnose and treat disease. It is focused on tailoring lifestyle changes and nutritional advice to suit your genetic profile.
The information from your genetic profile should give you more answers about your genetic weaknesses, how your body metabolises energy and how you gain weight, and how your body detoxifies and responds to inflammation, which is related to chronic diseases.
Diet and lifestyle changes form a very central aspect of preventative health measures to reduce your risk of diseases. The synchronisation of your DNA profile with a personalised dietary programme for your genes is known as nutrigenomics.
In general, nutrigenomics can help you have a better understanding of how best to care for your body through proper diet, nutrition and lifestyle choices.
For instance, you will be able to understand weight reduction, and how to manage your weight with a specially tailored exercise programme and other weight maintenance strategies.
All these strategies are conditional upon your willingness to change your behaviour and attitude.
Genetic profiling and tailored preventative medicine cannot give you any guarantees about preventing or curing diseases.
What it does is give you more control over your body and your health, empowering you with knowledge about what is going on inside your genes, so that you can make the best use of this information to stay well and age healthily.
DNA profiling will give you control over your genes so you can better control your current and future health.
Some medical centres in Malaysia now offer genetic profiling. Be sure to only seek testing and advice from qualified medical gene practitioners.
> Datuk Dr Nor Ashikin Mokhtar is a consultant obstetrician & gynaecologist (FRCOG, UK). For further information, visit www.primanora.com.