Quickie DNA tests not ready for prime time.

Kira Peikoff of the NYT paid for three different quickie DNA tests to see what diseases she was at risk for.  What she learned is that the tests are poorly calibrated and can contradict each other.  She's faulting the interpretation, not the testing.

23andMe

Only a few genetic markers are sampled (equivalent to "reading the first letter of every second page" in a book) and different ones are relied on for estimating the same disease. There are only a couple dozen rather rare diseases that can be predicted well. The data base used for estimating is still very small and even if you could afford a whole genome analysis, the technician wouldn't really know what to compare it with. This situation may improve dramatically in the near future.  Meanwhile, as the doctor Kira spoke with afterwards advises, “If you want to spend money wisely to protect your health and you have a few hundred dollars, buy a scale, stand on it, and act accordingly.”

Affordable technology