Because most of the world of genetic testing and personalized medicine is so new, there are still many questions it cannot address. Also, since most genetic testing only raises more questions, instead of providing answers, it may actually create more problems than it solves. Further, there are a number of legal and ethical implications surrounding genetic testing, most of which lean toward the negative.
Here are the questions which suggest those potential problems:
How accurate are the tests? There are no accuracy measures in place for most, in particular those that predict your health future. Say you are tested for the potential for lung cancer, and learn that you might develop it someday. You decide not to smoke and you don't develop it. But you can't know know whether the test was right or wrong to begin with because you took steps not to develop it.
Who can translate the information? A doctor may order a certain genetic test for you, or you may order one yourself on the Internet, or even purchase one in a store. Who can review the results for you? Geneticists are trained to do that translation, and as long as you spend time with one to learn what the results mean, you may learn something from them. But most doctors are not trained to understand them. If the results arrive in the mail, you'll have to do your own research to understand the answers.
Of course, the paperwork will also include disclaimers that accuracy cannot be guaranteed. Further, there could be mistakes in the testing itself.
Who owns genetic information? It may be owned by you, the patient, but it's being controlled by others. Or it may be owned by by the test developers, in which case they can do what they want to with it - keep it, sell it, share it - whatever they want. There are very few laws that affect genetic information so far. The laws that do exist, GINA, address discrimination and genetic code only.
How private is the information? Because testing is so new, laws do not yet exist to determine how the information can be used, and therefore even whether HIPAA privacy and security laws would be applied.
What will you do with the information? Few of these disease-prediction tests produce actionable results, with the possible exception of prevention tactics like managing one's weight, not smoking, getting plenty of exercise and others - all good steps regardless of the results of a gene test. Nor are there suggested treatments for the great majority of these tests -those tests which will eventually result in personalized approaches for patients. With few exceptions, those personalized treatments just aren't available yet.
As time goes on, more tests will be developed, more laws will be created to address them, and personalized medicine will become an effective approach to treating human beings for medical problems. But for now, patients must review the pros and cons of genetic testing for themselves to decide whether it is the right step for them.