Checking the Genotype through Click and Buy -- MEDICA - World Forum for Medicine

Checking the Genotype through Click and Buy

Photo: Two men studying a screen with DNA

Genetic analyses are not equally
meaningful: some reveal lots, others
nothing; © NCI Visuals Online

"Today genetic tests play quite an important role for the diagnosis of inherited and acquired illnesses", says Professor Claus Rainer Bartram, director of the department of human genetics in the University Hospital of Heidelberg. "More and more often, doctors rely on them if a diagnosis cannot be guaranteed on the basis of symptoms or to ascertain a disposition of a healthy person to a disease."

However, companies in the internet have started to earn their money with the help of the human chromosomes: The GentestShop offers genetic tests on Alzheimer's disease or diabetes on their website since July this year. The procedure is simple – a saliva test is enough – and expensive: 245 euros for Parkinson's, 364 euros to learn about your alleged disposition for cardiovascular diseases, and 836 euros for the most expensive one, searching for the genes connected to "Anti-Aging".

In return, the GentestShop's web page promises its customers "to be ahead of" possible illnesses giving them the possibility to counteract them before the disease may break out. The company that is run from Switzerland continues a trend which has already begun years ago: DeCodeMe from Iceland, for example, offers a similar online service already since 1996.

The German Society of Human Genetics has reacted and dismissed an explicit warning of genetic tests in February 2008: The authors call diagnostic offers from the internet "dubious". Wolfram Henn, professor for human genetics of the University Hospital of Saarland and one of the authors thinks that an "unspecific look into the future without a sensible reason" through genetic testing is not more than just a matter of spending a lot of money.

A lot of platitudes

"A diagnosis through such tests is often unreliable because in many cases research is not as far as the online offers suggest", says Bartram. No reasonable tests exist in the medical world that could predict a definite risk for periodontosis or for osteoporosis. The internet reality: Anyone can get a test on both diseases through a simple computer mouse click - the same is true for high blood pressure and heart attacks even though these two diseases are based on a nontransparent network of possible causes. The one known mutation is often merely one genetic piece of a jigsaw that in the end can cause an illness – together with many other environmental factors such as food and pollution.

A positive test result merely means that the patient has a higher risk of falling ill than other people. Yet how high or low this risk exactly is - most of the time nobody can say since too many unknown factors are involved. "In many cases, only a vaguely raised chance is diagnosed", according to Bartram. "We often only know one or two of two dozen genes which influence a disease. But even if somebody had discovered them all I would still not be able to tell the patient whether he will become ill or not because environmental factors also play a big role."

In the end, the results of genetic testing via internet comprise of a lot of platitudes. "I can give this kind of advice on the phone free of charge: eat lots of vegetables, do sports regularly, do not smoke and drink only little alcohol", says Professor Peter Propping of the institute of human genetics at the University of Bonn. As a matter of fact, Dagmar Mayer, head of the laboratory of GentestShop, explains that she recommends customers who were positively tested for osteoporosis lots of vitamin D, a well-balanced calcium household and sports.

Consultation prevents overhasty decisions

Mayer recommends similar measures in the case of an increased risk for Alzheimer's and Parkinson. She advises clients which exhibit a certain allele that raises the likelihood for Alzheimer’s to support the nerve cells with vitamin E. An advice that can hardly ease the nerves of those confronted with the test result - in particular, since it is still uncertain whether vitamin E has an influence on Alzheimer's at all.

Since no cure exists for diseases such as Alzheimer’s or Parkinson it is important to question before a genetic diagnostics matters like: "What possibilities are there after a positive result?" If the answer is "None!" a psychological consultation is of most importance to clarify whether the patient can cope with a positive result psychologically if there is any personal gain from such a test result. The human geneticist Henn observes that many patients make use of the right of ignorance after given a thorough medical consultation. However, whoever orders a genetic test online instead of going to the doctor receives neither medical nor psychological consultation and is left alone with the result: "Often, people cannot handle such a situation", Henn argues.

California at the forefront

"These internet offers are almost criminal for me", Propping sums up. All the more urgently he and his both colleagues wait for a law organising genetic diagnostics. From this law, the three human geneticists expect that a consultation by specialists before a test is compulsory and quality control.

In California, the genetic testing industry has already experienced first restrictions: Although no specific regulations apply to the growing industry, state law dictates that their laboratories must be fully certified and that customers can ask for a test only on doctor's orders.

Anke Barth