Genetic testing from a rod

Who wants to know his risk for various diseases can be genetic investigate. A test kit for example of the US-American provider 23andMe will cost 199 dollars. By Post by sending a saliva sample to a lab in North Carolina and receives a few weeks later, a genetic analysis of the risk for ten diseases. Some are very rare, but the Test also makes disclosures of actual diseases such as Alzheimer's disease or Parkinson's disease. About two years ago, the American health authority gave FDA the Test. He is allowed to be directly sold to customers without a doctor prescribed him. And also via the Internet to Europe and Switzerland.

In the US, such as Direct-to-Consumer Tests (DCT). More than 10 million people have their DNA already to analyze, and it will be more and more. Experts predict that the number could fold until 2022, ten. So far, the genealogical research was in the foreground especially, and also receives, in addition to all sorts of Lifestyle Information: how to tolerate coffee, whether you like cilantro or as a man will early lose his hair.

Controversial statement power

The efforts to check the medically relevant risks, with the enormous advances in genetic diagnostics (DNA testing) is likely to continue to increase. So the FDA had in October last, a further Test from 23andMe. This explores how good or bad you can tolerate medications. But can you trust such a genetic analysis, really?

"Scientifically, the Tests are on very thin legs," said Anita Rauch, Director of the Institute for Medical genetics of the University of Zurich. So 23andMe is not decoded the full genome of a patient, but focuses on a few, tiny changes, known as SNPs (Single Nucelotid Polymorphisms), in which only one letter in the DNA Text is changed. Through the examination of tens of thousands of patients we know today, several millions of such variants. A single SNP appears about striking is often the case with diabetics, associate researcher with the disease Diabetes.

"We received a number of calls from dissolved patients who are not able to arrange your test result."Anita Rauch, a geneticist at the University of Zurich

"In most cases, the genetic risk of a Person from small and very small effects from hundreds or Thousands of genetic variants. Until recently, it was therefore hardly possible, for any individual more than a very rough estimate of the genetic risk," says Christoph Bock from the CeMM research center for Molecular medicine of the Austrian Academy of Sciences in Vienna.

Also, the Test from 23andMe checks whether it is a carrier of such variants, for example, for Parkinson's disease. However, only the most common SNPs are to be controlled. And the risk for Alzheimer's disease assess the Test according to the gene variant APOE4, a major genetic risk factor for the disease. From the result, 23andMe calculates the probability of the disease. The U.S. company does not tell its customers that it is the result of a stone-carved truth. But how patients deal with such vague results, especially when it comes to such a terrible disease such as Alzheimer's?

Soon for prevention?

"We received a number of calls from dissolved patients who are not able to arrange your test results," said Anita Rauch, the Zurich-based geneticist. In Switzerland, such Direct customer-Tests à la USA is not allowed for medical purposes (a Patient must be from a physician, which instructs the Test), but you can now also easily over the Internet.

The risk assessment of diseases also plays an important role in research: "Currently, worldwide studies conducted or planned to examine the importance of the polygenic Risk score (PRS), so the disease probability for a certain disease, for the patient. It is important to know the expectations of patients and to explore the influence of the Knowledge of a high or low risk on the life style," says Jeanette Erdmann, Director of the Institute for cardiovascular genetics at the University of Lübeck. Behind it is the question of whether a patient falls slightly to drive more sports and eat less cake, if your genetic material says finding a high probability for a heart attack previously.

in the Future, the meaningfulness of such Tests for polygenic diseases, i.e. such, in which numerous genes and SNPs are involved could be better. Among them are many people suffer such as heart attack, Diabetes, or dementia. "Giant genome databases, together with modern Bio-Informatics methods to allow for part quite acceptable accuracies," says Bock, who can imagine a Direct-to-customer Tests, under certain conditions, also in the medical field: "The people would have to bring a certain amount of basic education, a kind of "genetic Literacy"."

Counter

is just not difficult to let possible Also people that use such Tests, it is expected from the health system with their questions and Worries alone. "But above all, the identified genetic risk through changes in behavior or medical measures to decrease", calls for a Bock.

Exactly this is not the case of the health tests from 23andMe in the case Of Parkinson's disease, you can prevent and Alzheimer's, at most, only to a certain extent with a healthy life style. Even in the case of a high risk of the disease may well not against taxes.

life style is also important

"Who has no specific symptoms, and should therefore consider carefully," advises because Anita Rauch of the University of Zurich, stressed but at the same time that genetic tests, depending on the question, can be useful. So, you are indispensable in some fields of medicine already today: in cancer medicine, for example, where the choice of therapy is in the foreground, and in the diagnosis of diseases, some of which go back to a single gene defect. About 4000 such diseases are already known, including many rare diseases. For preloaded parents with children request a genetic analysis may be advisable.

Parkinson's disease and Alzheimer's are suffering the dreaded age. It is therefore assumed that many people will be let out of mere curiosity test. To do this, but you should know two things: the first is To stay despite a high genetic risk for a disease healthy, but even without a genetic risk of developing. Because of the own life-style and not least the chance to play an important role.

(editing Tamedia)

Created: 10.02.2019, 17:35 PM