Thursday, June 19, 2008

Gene testing under threat in California

Oh boy. Some interesting news today on wired.com about the recent cease-and-desist letters sent to 13 genetic testing companies in the state of California. The letters can be found at wired.com and basically state the the companies, which include 23andme, and Navigenics, are breaching 7 statutes regarding patient testing and lab certification by procuring clients directly rather than through prescription. What is at issue here is the role of physicians in genetic testing, and much rests on whether genetic tests results are considered merely information for the consumer, or more significantly, diagnostic for the patient.

I recently had a conversation with someone who had taken a genetic test and is now in possession of her genetic profile and its associated risks. She assumed the risks were definitive and that we would progress to certain diseases states if she id not take action. So, she began taking the potions sold by the gene testing company in order to protect herself from what would otherwise be genetic certainties. There are a few things wrong with this picture. Firstly, the tests are not usually definitive. As I said in a previous blog, diseases are the result of complex interactions between genes, physiology and environment. There is simply not enough research to pin a particular disease on most genetic variants...yet. It may come one day but for now we have indications of potential risk and that is all. There are certain genes that do confer serious and significant risk; the Huntington's Disease gene tests are predictive for example and testing should, and is, approached with caution (see previous blog). Secondly, most individuals are not sufficiently knowledgeable about genes and their effects to know how to interpret the genetic 'information' they get back from gene testing. The lady I spoke to believed they were definitive, but also believed the vitamin concoctions she had purchased would prevent bad things. Again, there are signs that supplements may be helpful in preventing some diseases, but most claims are not backed up by rigorous study. Gene tests can seem self-serving when they are packaged with convenient supplements to assuage the fear wrought by the tests in the first place.

The action of the health department in California is intended to protect the public as far as I can see. The situation seems complex but I think it is simple at one level. Personalized medicine is touted as the next big thing by the media and the companies who provide the tools. The benefits are obvious; targeting the right medicines to the right people to reduce side effects and improve effectiveness. The public wants personalized medicine and sees genetic testing as a first step to take control over their 'personal health'. It is natural and to be expected that someone will want to make a business out of it. It is also natural that the doctors feel they have lost control over an important health parameter especially since the data requires objective interpretation to be useful. My vote would be to keep gene testing as an option for folks who want it, ensure it is ordered through physicians, require ordering physicians to maintain a state-of-the-art understanding of the implications of gene testing and the risks it can potentially identify to the patient so that they can counsel the patient on findings, and, ideally, ensure all gene-tested subjects are entered into an anonymized database that also tracks their disease development should it occur. This way, the knowledge base on genetic risk grows and informs future interpretations.
In the Wired.com article the CEO of Navigenics says she hopes the health department officials understand the difference between a genetic risk and a diagnostic. As I see it, the real question is, do the patients?
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