While I’m loath to disagree with ScienceBlogling Daniel MacArthur about genomics, I can’t really agree with his assessment of genetic risk prediction:
Wright provides a balanced review of the implications of the article, and finishes with a paragraph worth quoting verbatim:
However, far from supporting calls to forbid such tests being available DTC, this highlights the need for transparency</em in the provision of information.Companies offering genome-wide risk prediction services should ensure that their customers understand that, whilst the measurement of the DNA sequenceitself (the assay) will remain constant, the interpretation of the result (the test) is likely to change as the science develops.
Amen. As I have consistently argued here on Genetic Future, the solution to the alleged dangers of personal genomics is not banning the public from having access to their own genome (as Germany has recently done), or forcing them to seek permission from their doctor before peering into their own DNA. Instead, the answer is to ensure that companies provide at least the minimal information required for customers to make an informed decision about the utility of risk predictions, and to punish those companies who fail to do so with public censure and (if absolutely necessary) regulatory action.
To me, any test that yields either an increased risk or a decreased risk of disease depending on the analysis is not a test that should be used in medicine. This isn’t a quantiative difference (which would raise its own issues), but a qualitative one.
I can’t even begin to imagine the public health nightmare that would exist if we were to hold antibiotic susceptibility testing–how we determine if an antibiotic will work against a bacterial infection–to this same non-existent standard. While genetic risk prediction doesn’t have the immediate effect of failed antibiotic therapy, what if it leads to inappropriate treatment?
If it is an inaccurate medical diagnostic, then it should not be used. Because, like it or not, anything that says “genome” or “DNA” will be granted special status (look at the criminal justice system). Most MDs aren’t population geneticists or statisticians*–like most people, they want an answer that is robust**. Expecting after-the-fact regulation to be effective just isn’t realistic–if a diagnostic isn’t reliable, don’t release it as a diagnostic because it will be used.
I do think genetic risk prediction will be a useful tool. Will be. But I’m not sure that right now it’s where it needs to be. If we want rich guys who sequence their genomes to have fun, or if people, who want to advance medical science, are willing to be tested, that’s one thing. But a diagnostic is another.
*I’m not impugning the intelligence of doctors, but if you need to be an active researcher in this area to understand the limitations of the diagnosis, then it’s not ready.
**Apparently, robust has become a managerial-speak buzzword. I simply mean that the result is not hyper-sensitive to other factors.