Universiteit Leiden

nl en

Richard Karlsson Linnér: ‘I expect a future where a genetic test will be as much a no-brainer as getting X-rayed.’

Assistant Professor Karlsson Linnér, who works at the Department of Economics, is one of the recipients of a Veni grant. His research on the accuracy of preventive genetic testing is a fine example of the intersection of economic science and law.

In recent years, preventive genetic testing has really taken off. It offers people a prediction of their future health or future risk of developing a disease. Rather than looking at a single, isolated gene to determine a genetic disorder – for example Huntington’s disease, an incurable neurodegenerative disease, has a single defective gene on chromosome 4 – the entire genome is considered.

Richard Karlsson Linnér

Ancestry and future health: the same test

These so-called ‘genome-wide’ tests are not yet routinely in use in clinical care. However, there are already health care companies offering direct-to-consumer testing. In the same way as people can send off their saliva to determine their ancestry, they can now learn their risk of getting breast cancer, high cholesterol, or Parkinson’s disease. Karlsson Linnér, an economics graduate who continued his career in social-science genetics, specialising in psychiatric genetics, explains: ‘In a genetic health report, it might say for example: “based on your genes you are in the top 10% of people with a genetic risk of developing cardiovascular disease”, while someone else’s results might state that they have “an average genetic risk for coronary artery disease”.’

Pros and cons

Advocates of the widespread use of this type of genetic testing point to the possible positive health effects. Once people are aware of their predisposition, they can incorporate changes in their lifestyle, or be more aware of signs and symptoms of the flagged conditions. They can then get treatment sooner, should they go on to develop the diseases. Sceptics, however, point to the risk of discrimination since the outcome of such testing may affect, for instance, chances of employment (employability being dependent on the genetic risk of getting sick), getting insurance cover (being denied life insurance e.g. because of the high risk of early on-set Alzheimer’s), or the premium charged for insurance (a higher risk might entail a higher premium).

How good are the tests?

Risk is the key word here. Having an increased genetic risk of developing a disorder or illness does not necessarily mean that the person concerned will also go on to develop that condition. However, because of the potentially far-reaching implications of the uses of these tests, as well as their expected widespread use, the predictive value of the tests does matter. Put differently: are the genetic tests as good as they are advertised to be? Karlsson Linnér’s research will cover precisely that question. Specifically, he will study the current and future predictive value of genome-wide tests that are still being developed and that will improve considerably in the next few years. By creating a harmonised resource covering many medical conditions to be shared with other scientists, this research is also fundamental as it attempts to lay the foundation for further scientific research. Hence the importance of the Veni grant – funding that is awarded ‘to boost innovative research and promote advancement at scientific research institutions’.

Why the predictive value matters

Karlsson Linnér’s research is very timely. He gives the example of genetic screening for embryo selection, a service that is supposedly already offered by fertility clinics in the United States. In a nutshell, using this treatment, couples seeking fertility treatment have embryos in which a certain predisposition for a certain disorder is found ‘discarded’. Only the embryos that do not have certain increased genetic risks are fertilised (‘selected’). Karlsson Linnér: ‘However, it’s uncertain whether such tests have enough predictive power to select the correct embryos on the available information. And if you cannot actually select, then in many people’s opinion, you would be falsely advertising these services to prospective parents.’

If the technique underpinning these tests gains a bad reputation through controversial use, such as embryo selection, this could harm the public’s trust and impede the advancement of genetic testing altogether. Karlsson Linnér: ‘I fear it will either stop the positive development of the use of these tests, or lead to public backlash that prevents the good use of these technologies.’ He stresses that he sees ways in which society may benefit from the use of genome-wide tests. At the same time, he mentions the importance of protecting people from the apparent dangers.

However, the question is not whether these tests will be used on a large scale, but when and under what conditions. Karlsson Linnér expects the tests to be introduced in routine medical care soon, ‘maybe even within one or two years, and certainly within five or ten’. ‘And I expect them to be ubiquitous in society and in healthcare in twenty to thirty years.’ ‘I also expect that in this science-fiction future of health care, doctors will prescribe genome-wide tests as routinely as X-rays. And the genome-wide tests are so easy and cheap as well; they're amazingly cheap compared to other medical technology.’


Karlsson Linnér plans to determine the predictive value of the tests by analysing statistical data of real people and enhancing this with information on the disease heritability, the variability in a population related to genetic differences between people. A large body of medical literature has estimated the heritability of almost any medical condition. Basically, Karlsson Linnér will then combine these figures to determine how well future tests will be able to predict certain diseases or disorders.

Where economics and law interact

In the further stages of his research, together with legal scholars from Leiden Law School, Karlsson Linnér will draw up proposals in relation to policy, i.e. advice on what uses of this type of genetic testing should be allowed in society and the boundaries to be put in place to safeguard those involved. To come up with meaningful policy recommendations, he will have to apply his method to various disorders. He explains: ‘While it's the same technology, it doesn’t work equally well for all disorders. Therefore, you can’t study the accuracy for only one disorder and then decide what the right policy should be. You really need to look at many disorders. Maybe even a fine-grained policy would be that there are exceptions to the use for some disorders, but not for others.’ 

Photo by Sangharsh Lohakare on Unsplash. 

This website uses cookies.  More information.