The expanding world of genetic information has made consumer genetics testing, either to determine the chance of genetic diseases or to track your ancestry, or both, a popular analysis. Less well known is the, also expanding, world of genetic data used to help diagnose and treat diseases. I know what you’re thinking, you already know about this. This is why an amniocentesis is done—searching for genetic abnormalities (for example Down Syndrome). Genetic testing is routine. Yes, but possibilities in this realm have been changing and it appears that medical science can’t change so quickly.
Someone made a stab at the number of genetics tests available in 2009. They arrived at an approximate number of 2000. In 2017 another analysis, by a different group, found the number of tests available to be about 75,000. That’s a 3650% increase. Prenatal testing, like that mentioned above for Down Syndrome, is one of the largest growing areas.
Genetic testing isn’t just done to see if your yet to be born child will have a debilitating disease or that you have a particularly gene variant (an allele) that might cause you problems—that is, one that gives you, in effect, the disease. Genetic testing is also done, routinely, to look at the specific changes to the DNA in a tumor of a cancer patient, look for DNA alteration that might affect the severity of a disease, to look for the possibility that you, even though you don’t have a disease, might pass on a ‘bad’ allele to your kids, and …AND here’s the one that is most unknown, to indicate to your doctor whether a specific treatment will work for you or not.
Let’s pause on that last one a minute. It turns out that for a specific treatment drug, those for example that treat asthma, diabetes, arthritis, Alzheimer’s, and depression, will work on between 30 to 75% of the individuals treated. Doctors will routinely switch drugs if one doesn’t appear to work for you, for example, to keep you blood pressure down, they might swap drugs multiple times to find the one that best works for you. This is a bad way to determine a treatment, first because you are dealing with the symptoms and destruction wrought by the disease during the experimental period, but also because you’re ingesting a drug that might be harmful. If I do that I, at least, want a nice trip out if it. What we need to do—I’m using the Royal we here—is take advantage of gene testing to determine, BEFORE treatment, what treatment will work for a patient.
This is the onrushing change to medicine that is called Personalized Medicine. This whole field, yes it is its own field (or soon will be), is sometimes called Genomic Medicine. Of course all medicine should be personalized because everyone, yes everyone, is different. But these days personalized medicine means, basically, adjusting your treatment to fit your genes.
The largest barrier to more personalized medicine now? Your doctor. This type of treatment needs to become a major part of the medical school curriculum but so many changes have happened so fast that no one could keep up. Treatment regimens need skilled nurses, skilled doctors, and now skilled genomic specialists.
Another problem is for these advances to be available for all populations. Having access to genetic testing may be determined by the all mighty dollar $$$$. Genetic testing can be expensive. Who is paying? Let me quote one of the sources below because they said it better than I can:
“To equitably advance genomics in a way that can improve the health of all populations, the future of genomics must begin by looking at those left behind.” (Jooma et al 2019).
Problems to overcome, yes. Many of them. But don’t be frightened. I’m looking forward to the age of Genomic Medicine, are you?
Sources and Readings:
These are all open access: We love open access.
Jooma S, Hahn MJ, Hindorff LA, Bonham VL. 2019. Defining and achieving Health Equity in Genomic Medicine. Ethnicity and Disease 29: 173-178.
Juengst ET, McGowan ML. 2018. Why Does the Shift from “Personalized Medicine” to “Precision Health” and “Wellness Genomics” Matter? AMA Journal of Ethics 20: E881-890.
Phillips KA, Deverka PA, Hooker GW, Douglas MP. 2018. Genetic Test Availability And Spending: Where Are We Now? Where Are We Going? Health Affairs 37: 710-716.
Phillips KA, Trosman JR, Weldon CB, Douglas MP. 2018. New Medicare Coverage Policy for Next-Generation Tumor Sequencing: A Key Shift in Coverage Criteria With Broad Implications Beyond Medicare. JCO Precision Oncolology 2: 1-6.