The double helix of DNA (Credit: Reuters / EPA Photo)

By sending a saliva sample to four different companies that do genetic testing, a person may obtain four different predictions about diseases that could contract.

The DNA tells all of us, the important thing is to know how to read. And they are more than willing to pay serious money to find out if they face diabetes, prostate cancer or infarction. The tests are a shame that, according to a recent report released in the U.S., are not reliable at all.

The Government Accountability Office , an independent agency that works for the U.S. Congress, he wanted to test the accuracy of genetic testing kits that some companies offer to consumers at a cost of between 300 and 1000 dollars ( here in pdf file report). The result was that four of the five people who had sent a sample to analyze the results obtained are in contradiction to their actual health condition and their family history.

But not all. The exact same DNA sample gave very different results in tests carried out by the companies tested. A woman of 37 years, for example, had a second test at above average risk of contracting leukemia, while another test based on the risk he was only average, and in a third analysis was below average. Who should believe and how it should behave?

The same applies to the risk of contracting prostate cancer in a man of 48 years. Based on the results posted by two of the companies involved his risk was average, another test identified a risk below average, while a fourth examination carried out by another company foresaw a risk above the average.

"If the tests were accurate the same DNA should result in identical predictions," said Gregory Kutz, the Government Accountability Office. Whose conclusion is that these tests sold directly to consumers, sometimes even with a very aggressive marketing, "are misleading and of little use to consumers."
The sale of these tests should soon be regulated by the Food and Drug Administration, U.S. government agency gives its approval to the sale of drugs and medical devices .

In fact the FDA has chosen not to regulate simple diagnostic tests developed by independent laboratories, while adjusting the tests are considered medical devices, ie those used to diagnose a disease or to prevent it. None of the genetic tests being tested by the government has obtained an assessment by the FDA for reliability, accuracy and clinical relevance.

From now on things will change. So the 'FDA has written to six U.S. companies working in the field of genetic testing, also including 23andMe , the company funded by Google and founded by the wife of Sergey Brin, inviting them to attend a board meeting to discuss how to regulate their products.

Representatives of several of the companies involved ( Pathway , 23andMe, Navigenics ) have defended their own tests support that help consumers to change their habits and thus avoid problems such as diabetes. But perhaps enough to apply some common sense advice that applies to everyone and does not cost anything, without having to spend hundreds of dollars for analysis, which currently seem to have the same accuracy of the horoscope.