05 July 2017 - 16:10
Genetics & prevention
The rush to carry out DNA tests
“The time has come in America when the same kind of concentrated effort that split the atom and took man to the moon should be turned toward conquering this dread disease. Let us make a total national commitment to achieve this goal.”
It was 1971 when Richard Nixon, president of the United States, pronounced these words. The disease in question was cancer. That year the White House announced a war on tumours as the cornerstone of the country’s policy. Significant funds were granted but the first results only arrived in the mid 1990s when the death rate finally began to decrease. This was because, as a detailed investigation by The New York Times has shown, for too long the focus had been on drug treatments while the importance of prevention had been understood far too late. Although drug treatments are of fundamental importance, regular checks and greater care about lifestyle choices really make the difference: nowadays no one refutes this.
In recent years prevention has become increasingly sophisticated and accurate. Largely this has been due to its close relationship with genetics. Thanks to the development of technology and advances in research, it is possible to analyse almost all of the sequences of an individual’s genomic inheritance to detect a possible mutation and predisposition towards certain diseases.
Remember the case of actor and director Angelina Jolie. A few years ago she chose to have a double mastectomy after genetic analysis discovered a mutation in the BRCA 1 gene, which increases the probability (by up to 60%) of developing a breast tumour. Angelina Jolie’s doctors believed that this mutation was serious and she chose to undergo a preventative operation even though there was no certainty that she would get cancer were she not to do so.
The crux of the matter is that a mutation of the BRCA 1 does not necessarily lead to a breast cancer. Genetic analysis does not provide answers that are 100% clear. For this reason the Medical News Bulletin recently commented that although such tests help enormously to understand and develop improved strategies for the reduction of risks from breast tumours, the tests need not be carried out in every case. A rush to undergo DNA tests must be avoided. Furthermore, there are some other aspects that should not to be ignored, such as the psychological element. Knowing that you are potentially vulnerable can condition your mood and health, and this is destabilizing, not to mention the fact that having a DNA test performed does not come cheap. Tests can cost up to 3000 dollars, so they are not an option for everyone.
This combination of psychological and economic factors is not only pertinent to breast cancer but also other forms of tumours or types of illness that are partly predictable thanks to the progress of technology and science. One of these is thrombophilia, an anomaly of blood coagulation that raises the risk of thrombosis. A study by the University of Michigan, quoted on the website statnews.com, revealed that the genetic tests for this illness, although they offer useful indications, do not change the treatment in the case that the condition is discovered. Then we need to take into account the anxiety that tests cause and also patients’ requests for new further in-depth follow up tests with costs that can ensue not only for those undergoing the tests but for the entire community. A balance needs to be achieved and this is not so straight forward.
Nevertheless, developments are afoot to significantly lower the costs of testing. Some startups are developing techniques for DNA analysis that are within reach of those with much smaller budgets. The one to have received most press coverage is 23andMe, a company that sells a kit for analysing saliva samples. The company is supported by Google but the results of this analysis are not believed to be totally reliable and, in any case, represent only an initial indication. Deeper investigation requires a geneticist and here lies a further problem because this medical specialization is not common: getting an appointment can be a lengthy process. In order to solve this problem, Genome Medical is trying to develop a business model based on providing video consultations for doctors and patients.
There are numerous other companies that are getting involved in this market, which is destined to take off in the coming years. Estimates predict that current spending on genetic tests ranges from between 300 and 600 million dollars per year, but by 2023 this could reach the incredible sum of almost 90 billion dollars.
However, the lack of statistical data and other factors mean that is still difficult to fully understand this new, incredible page in the history of man and science.
The latest development in this field was made at the end of last year by Chinese scientists at the University of Chengdu following experiments on a group of cancer patients. DNA samples were taken from the patients, a defective gene was eliminated and the patients were injected with their own DNA that had been “modified”. All of this took place using a new technique called CRISPR–Cas9 that is so cutting edge that in the United States they are only just beginning to experiment with it. The race to develop gene editing technology is now seen as another part of the geopolitical challenge between the two superpowers.