by Dr. Sanjay Gupta
Chief Medical Correspondent

How times have changed. This morning I reported about DNA paternity tests. That's right - you can go to the drugstore today and buy a genetic test that can determine who is the father of the child. In fact my producer Danielle bought two from the Rite Aid by her house - she did get a few funny looks.

According to the directions, you take a cotton swab and rub it inside the child's mouth. That will provide enough DNA for the test. The man who may or may not be the father has to do the same. After you collect the DNA and send it in, it takes three to five days for the test to come back, and you can even go to a confidential Web site and get the results.

The big question is of course, how accurate is the test? You really wouldn't want to be wrong about this. Well, according to an expert we interviewed, these tests rely on around 15 markers, and that makes it pretty accurate. If you are able to collect the child's, the potential dad's and the mom's DNA, the test is 99.9 percent accurate. With just the child's and the potential dad's DNA, it is closer to 99 percent accurate. Not bad. But the truth is, we don't know exactly how accurate these tests are because they aren't regulated by the FDA. The manufacturer says this is the same test forensic and legal agencies have been using for years.

The test costs around $20, but if you read the smaller print, you will see that there is also a $119 lab processing fee, so not cheap. And, as the included materials state, if there are multiple "alleged" fathers, the costs will be even higher... hmmm.

So, here we are in 2008. Over-the-counter genetic tests now are available - testing everything from paternity to your risk of developing diseases such as Alzheimer's. I actually took five different DNA test kits to compare their accuracy (watch Dr. Gupta's report on take home paternity tests and the DNA tests here). I'm still waiting for the results but I'll blog about it when they come in.

What do you think about over-the-counter genetic tests? Would you use one? Do you trust them?

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