Don’t Count on 23andMe to Detect Most Breast Cancer Risks, Study Warns - The New York Times
Good morning all,
In lab recently, we have been considering some of the aspects of personalized genetics, with particular reference to genetic ancestry and the use of DNA databases in forensic and criminal investigations. During our introduction to this topic of personalized genetics, I noted that there also are significant interests in using personalized genetics as a way to assess health. Indeed, many of the commercial entities that offer to analyze an individual's DNA also offer to provide some estimate of their health risks for a variety of conditions. I also said at the time that, in our discussions, we would largely stay away from the health aspects of these services, as they are much less well-established than are the ancestry ones.
I described to you recently how using DNA in criminal investigations relies upon combining two large databases (of individual genomes, and police records) to look for intersections, in order to highlight potential crime suspects or their relatives. Using DNA to assess health risks works in a very similar way, this time by evaluating databases of individual gene sequences against databases of individual health and lifestyle records. These types of tests are called genome-wide association studies (GWAS). GWAS are useful only when based upon thousands (usually, hundreds of thousands) of individuals. These are not experimental methods, so they cannot provide definitive proof of anything, but they can reveal interesting "associations" - places where genetics and health vary in consistent ways.
There are lots of large databases of public health records and DNA sequences, and many researchers and even some governments are using them to investigate public health. The commercial operatives also offer to do the same for their subscribers. In the news this week is a reminder that simply claiming that such a service is available does not mean that it is a complete or accurate one. Researchers at not-for-profit health institutions are warning that those who use 23andMe health assessments of genetic risks for breast cancer (the leading type of cancer in women) are potentially being misinformed of their genetic risks. This is a big deal - many people make dramatic decisions about their health and life when learning of their genetic risks for breast cancer, such as undergoing mastectomy (breast removal). At the opposite extreme, what if a person has a substantial risk, but is told that they do not?
The federal Food and Drug Administration (FDA) has given its approval for 23andMe (and other commercial) genetic health assessments, and this is an important reminder that FDA approval is not meant to imply that the services are the best available, more so that the services are generally safe and perhaps useful. Anyone who is using a commercial service to evaluate their genetic health risk should follow-up with their physician if they have any concerns - the better hospitals can perform some of these tests on their own. "Caveat emptor", or "buyer beware" - commercials services, by design, place emphases on their interests, first. When in doubt, a second opinion from an independent health professional is the best course of action.
Have a great weekend -
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