Source: http://www.nytimes.com/2013/12/31/scienc...

Like others, I turned to genetic testing, but I wondered if I could trust the nascent field to give me reliable results. In recent years, a handful of studies have found substantial variations in the risks for common diseases predicted by direct-to-consumer companies.

I set out to test the tests: Could three of them agree on me?

The answers were eye-opening — and I received them just as one of the companies, 23andMe, received a stern warning from the Food and Drug Administration over concerns about the accuracy of its product. At a time when the future of such companies hangs in the balance, their ability to deliver standardized results remains dubious, with far-reaching implications for consumers.

My experiment ran into hurdles from the start. After I ordered 23andMe’s saliva test kit, which for $99 promised a report on more than 240 health conditions and traits, it turned out that I could not legally send it in; the New York State Health Department forbids any labs that lack a state permit to accept specimens from a health-related test. Luckily, my in-laws mailed it from their home in New Jersey.

Then I learned that the other two companies I planned to approach were no longer offering genetic testing. Additional research led me to two more: Genetic Testing Laboratories and Pathway Genomics. G.T.L. charged $285 for a report on 25 disease risks, and required a professional sample collector to draw blood; Pathway charged $399 for a report on 24 disease risks. (In 2010, Pathway planned to sell its saliva test kit at Walgreens, but abandoned the idea after the F.D.A. challenged the sales. Now Pathway requires a doctor to order a kit on a patient’s behalf.)

After my tests had been sent, I braced myself for the revelations about my DNA. It took about two months to receive all the results, and when I did, the discrepancies were striking.