More knowledge on the relationship between DNA and health

Globally, various studies are being carried out on DNA and health. Exploring and determining the relationship between health and DNA requires substantial data, from patients and from healthy citizens. Many countries have national research initiatives for this, in which citizens and patients can voluntarily participate. Data collected from these projects can be used to build a better understanding about specific DNA variants that may explain why certain individuals develop rare conditions. Additionally, these research projects   can help understand the correlation between DNA and the likelihood of developing more common health conditions. RIVM has a cohort  in which Dutch people voluntarily participate: the Doetinchem Cohort Study .

To strengthen genomics research and improve the availability of DNA data, RIVM represents the Dutch Ministry of Health, Welfare and Sports in the European 1+ Million Genomes initiative. This project explores how we can safely collect DNA data from volunteers in Europe and make it accessible. 

These initiatives primarily help to build greater knowledge of the relationship between DNA and health. Ultimately, it is important that the new knowledge also leads to improved health, for example, through better diagnoses in hospitals or through new safe and appropriate tests in screening programmes. The European 1+ Million Genomics is further described on the website of the European Commission’s European ‘1+ Million Genomes’ Initiative.

DNA technologies to improve health

There are many developments in Public Health Genomics, such as new DNA tests and gene therapies. For example, there is a technology that maps an individual’s entire DNA. This is called whole genome sequencing. Another type of DNA test only looks at specific DNA locations linked to a disease. This is called targeted sequencing. Scientists are also looking into the application of DNA tests on different types of materials, such as DNA material that occurs naturally in blood, also known as cell-free DNA. In the future, this may be of interest for population cancer screening or innovations in the current NIPT (non-invasive prenatal test) screening programme and newborn screening programme. 

RIVM stays up to date on these developments and participates in national and international research projects.

Whether and how these technologies can best be used to improve health is often the subject of extensive research. Aspects that require further investigation include:

• for whom the test is intended (a patient or a healthy individual);
• in what setting the test should be offered (as a national screening programme or in hospital);
• what quality requirements the test must meet (accuracy of the test and speed of the test);
• whether the DNA test is more useful than another type of test?

Preventing commonly occurring conditions

Conditions such as cardiovascular disease, cancer and diabetes are caused by a combination of DNA variants, lifestyle and/or the environment. Everyone has variations in their DNA, also called genetic variants, that can increase or reduce the risk of developing a condition.

RIVM has studied (in Dutch) how DNA tests can help prevent common conditions when combined with lifestyle advice or specific therapies. It has found that for a few of these conditions, there are DNA tests that can properly predict the risk of developing them. Furthermore, the recommended lifestyle advice for someone with an increased risk of developing a condition is often the same as general lifestyle advice, such as abstaining from smoking, engaging in sufficient physical activity and eating a varied diet. Carrying out a DNA test to personalise preventive lifestyle advice or therapies, therefore, still seems to be of little use for most of these commonly occurring conditions. However, there may be opportunities for certain specific conditions, such as age-related macular degeneration, which affects vision, and the cardiovascular disease familial hypercholesterolemia. Rapid developments may bring more opportunities in the future.

Commercial DNA self-tests

The commercial market is constantly evolving, including in the area of DNA self-tests. These are tests that consumers can buy without a doctor’s intervention. DNA self-tests can look at different characteristics, such as predisposition to allergies, sports performance, medication response and the risk of various conditions. The reliability and usefulness of these tests are often limited, so these tests do not offer much added value for health. Furthermore, consumers are not always aware of the potential risks of these tests, for example in terms of privacy violation and data sharing, as well as the information they can provide about (unknown) familial relations. You can read more about this in the RIVM report ‘Opportunities and risks of home DNA tests’ and the associated scientific publication. 

You can find more information about the range of self-tests, including other kinds of self-tests, in the brochure ‘Range of self-tests in the Netherlands’ (in Dutch) and on the web page Testing on human bodily material (in Dutch).

Relationship between DNA and medication response

These days, there are specific DNA tests that look at the relationship between DNA and medication response. This is also called pharmacogenetics. Pharmacogenetics uses DNA information to estimate the potential adverse reactions people may experience when using specific medicines or for whom certain medicines will not work. This information can help tailor the medicine and/or dosage to the individual. In practice, treatments and dosages are currently tried consecutively to ultimately find the most effective treatment for a specific patient. Pharmacogenetics can help to determine and achieve the desired effect of medication more quickly.

Currently, pharmacogenetics is not yet offered to every patient. Research is being conducted to determine which patients or individuals are best suited for these tests, when they should be carried out and which professionals should be involved. You can read more in the RIVM publication Pharmacogenetics at the pharmacist and GP (in Dutch).