Genetic testing for adult onset diseases used to be mainly a medical service. In most cases a person who had a certain genetic disease that was prevalent in her family would go to test to see if she carries the genetic mutation. For example, a woman who had several cases of breast cancer in her family would test for the breast cancer genetic mutation BRCA1/BRCA2 to see if she carries the mutation and has a high probability of getting the disease. But, the proliferation of direct to consumer genetic testing changes the nature of the service to a consumer service. Companies like 23andme and Pathway Genomics (who was planning to start selling its kits in Walgreens) offer consumers the option to buy packages of tests (ranging from 25 to over a 100 conditions). Consumers often buy the tests to satisfy their curiosity or they may even receive them as a gift. People purchasing the testing packages usually do not consult a medical professional when deciding to undergo the tests and receive the results alone by accessing a website.
Yesterday I spoke before the FDA, which is considering regulating direct to consumer genetic testing. My presentation was based on a symposium piece I am working on. I argued for the need for a medical professional to guide people throughout the process and advise them not just on the interpretation of the results but also earlier in the process to determine what genetic information they actually want to have.
Interpreting the results of genetic tests is not easy. Unlike other over the counter tests, like a pregnancy test, which gives a clear positive or negative result, genetic tests are about probabilities. Even a person who tests positive for a certain mutation may still not get sick depending on other non-genetic factors. People have a hard time understanding the results of genetic tests and for that reason there have been many calls to require the guidance of a medical professional for the delivery of the results.
But I believe focusing on the interpretation of the results is only half the issue. It is important to have professional guidance also at the outset to determine what tests to undergo. A medical professional should guide individuals and tailor the panel of tests to the individual who desires to test. Why is that? Well, first of all, some people, if they get a chance to give it some thought, may not want to know all their genetic information. For example, a person may prefer not to know that he is likely to get Alzheimer’s at a young age. Secondly, not all genetic information is made equal. Some genetic tests do not convey that much useful information. For example, a positive result in some tests may only demonstrate a slightly higher likelihood of getting the disease than the probability in the general population. Eliminating such tests at the outset will facilitate the interpretation of the results. It would be possible to focus on the truly important positive results at the end of the process.
To achieve all this it is important for the law to require the guidance of a medical professional who is not a representative of the genetic testing company. A medical professional working for the genetic testing company may have good knowledge of the tests, but could have an interest in having the consumer purchase as many tests as possible. This could place him in a conflict of interest with the consumer who could be best off by purchasing a more limited panel of tests tailored specifically for him.