The promise and peril of home genetic test kits

It is now possible to learn about your predisposition to certain diseases simply by buying a home genetic test kit, swabbing your mouth and sending the saliva sample to a laboratory. But should you be allowed to? That question, raised by a recent article in The Times, is best answered: “Yes, but …”

That the question could even be posed is a testament to the breathtaking progress made by genetics. These days, for a fee, you can send a saliva sample to a genealogy firm and discover which of several ancient populations included your ancestors. Genetic medicine has also provided remarkable evidence that can help couples decide whether to have a child. Perhaps the most dramatic new products are the home testing kits that the Food and Drug Administration is planning to more tightly regulate, which enable people to know more about their likelihood of developing certain hereditary diseases.

One of the arguments against making such kits available is that some people with untreatable diseases will be depressed by the results. Another is that the tests may produce false positives. A third is aesthetic — that it’s unseemly for a valuable scientific tool to be crassly commercialized.

But it’s snobbery to criticize the popularization of a process that provides valuable information. If a pregnancy test is acceptable, so are these disease-testing kits. In both cases, the test reveals information that the subject is free to follow up on with a doctor. The difference is that without the disease-testing kits, a person might not become aware until much later — perhaps too late — of his or her condition. In some cases, a propensity to a certain disease can suggest changes in lifestyle and medication

Here’s the “yes, but ...” The main objection to home genetic tests, one that has concerned the FDA, has to do with false positives and false negatives. With that danger in mind, the agency plans to increase regulation of home genetic kits, which it considers to be “medical devices” subject to its authority. It has also asked a panel of experts to consider the implications of home tests for the health of consumers and the practice of medicine.

Knowledge is power — and these kits provide individuals with powerful knowledge about their genetic profile. It’s vital, however, that the knowledge be accurate.