Is genetic testing a waste of money?
Researchers at the Erasmus University Medical Center in Rotterdam, the Netherlands, working under the guidance of epidemiologist Cecile Janssens, said that screening thousands of genes for the presence of genetic variants associated with diseases is practically useless.
The study of the results of genetic tests offered by several competing companies has led to very different results. In some cases, similar predictions could be made by tossing a coin. In fact, it turned out that the tests, which sometimes cost more than 500 pounds, are a waste of money and can mislead people about trends in their health status in the future.
During the study, scientists used a computer program to simulate the genetic information of 100,000 ordinary individuals. After that, they processed it using formulas used by two of the largest companies specializing in genetic testing – deCODEme and 23andMe – to predict the risk of 8 diseases, including myocardial infarction, prostate cancer, celiac disease (food allergy caused by insufficient cleavage of grain proteins in the intestine), macular degeneration (age-related retinal degeneration) and diabetes.
According to the authors, tests from different companies produced conflicting results on the risks of developing a number of diseases. Often the reason for this was the use of different data on the prevalence of diseases in the population.
The second weak point of testing was that the subject of analysis was exclusively genetic factors, whereas the development of many diseases is largely determined by lifestyle and other environmental factors.
In some cases, the results of testing using the deCODEme model suggested the existence of more than 100% probability of developing five diseases, including macular degeneration. Such results raise doubts about the adequacy of the test results, which the researchers are going to report on at the European Conference on Human Genetics in Amsterdam.
deCODEme Executive Director Kari Stefansson, of course, said that Dutch scientists had misinterpreted the computer models they used. She noted that the company never indicates the existence of risks exceeding 90%.
For his part, Brian Naughton, Chief researcher at 23andMe, noted that the company's specialists realize that most people are characterized by low risks of developing most diseases. This is a reflection of the expectations of specialists, and not an indicator of the inadequacy of the results. He also stated that the company takes active measures to ensure the accuracy of the results at all stages of the data analysis and presentation process. At the end of his speech, he also warned that it is not necessary to draw conclusions about the accuracy of the data provided by 23andMe based on the analysis of the results obtained by deCODEme or any other company.
Evgeniya Ryabtseva
Portal "Eternal youth" www.vechnayamolodost.ru based on the materials of The Guardian – Genetics tests flawed and inaccurate, say Dutch scientists.
Portal "Eternal youth" http://vechnayamolodost.ru03.06.2011