Post written by Dr. Bradley Hiner
Some of you may have heard of this: there is a high-tech, “personal genetics” company called "23andMe" in California that wants you to spit in a cup, send it to them and for a fee will run a series of genetic tests on your DNA (we all have 23 chromosomes, hence the name). It is being pitched as “helping to advance the cause of science”, and is being sponsored by the Michael J. Fox Foundation no less to “help find the cure for Parkinson’s”.
My opinion? Let’s slow down and take a look at a few details:
- Bear in mind that this is a privately held company that will now have possession of your DNA, and can do whatever research in the future they want to. It can be stored in perpetuity, and used for whatever purposes they want.
- One of the co-founders of the company is the wife of Google co-founder Sergey Brin. Google is an investor in the company. Google may be many things (like a great search engine) but do you want them owning your DNA?
- A few basics about genetic testing in Parkinson’s:
- While there have been genes discovered that are associated with PD, the fact is that the vast majority of patients do not inherit it nor do most cases “run in families.”
- The known genes that may cause PD are quite rare, and even in those cases, there may be a difference in gene expression, something known as variable penetrance and expressivity. That means even if you are one of those rare individuals who have the gene, there’s no way of knowing if or how it will be expressed.
- So you spit in the cup, pay your money, and wait patiently by the mailbox. In the mail some time later you receive an official print-out of your genetic profile. Let’s say you are positive for one of the genes known to cause PD (for example, LRKK2). Now what? Is there anything you can do about it? Is it going to change your treatment? Are you now going to disclose this information to your family, so they can worry about inheriting it? How far along the family tree will you have to alert people? How is this information going to affect your children, and their children? Will the grandchildren need to be worried about it?
- The fact is, until we have a treatment that is “neuroprotective,” i.e., can prevent Parkinson’s disease and its progression, there is little to no value for you, the patient/consumer to have this kind of information. Maybe someday, but not now.
- Finally, the test will be scanning your genes for many things, not just those related to PD. What are you going to do if you get unanticipated results, or results that you or your primary care doctor are not equipped to interpret?
The company promoting this testing themselves admit the following:
"The decision to learn about your genome, however, is a significant one deserving of serious thought. Currently there is no targeted therapeutic response to learning that you have a specific genetic variant linked to Parkinson's, and such treatments require additional research. You may also discover other unexpected health information unrelated to your PD status. While we think you should take this decision seriously, we also believe that the choice to discover this information is yours to make."
In patients with Huntington’s Disease (unrelated to Parkinson’s), we have a very specific genetic test that can predict with certainty whether or not you will get the disease. This information may be important from the standpoint of family planning, for instance. But very strict guidelines have been set up such that this information is handled very carefully, so that if the test is positive the patient and family are not left on their own to deal with it. Imagine getting test results in the mail and trying to come to grips with it while standing at the end of the driveway in front of the mailbox.
My opinion? Over-the-counter genetic testing is a bad idea. Genetic testing will almost certainly have a greater and greater impact on medical care in the future. We are hearing phrases like “personalized medicine” in this regard. Already tests like those for certain types of breast cancer (“BRCA1”) or Huntington’s disease have substantially affected decision-making for individual patients and their families. But these circumstances involve professionals like medical geneticists and other skilled health-care providers who can take that information, interpret it and help the patient make informed decisions and deal appropriately with it.
| ||The following is feedback received for this blog:|
I have found the exact opposite to be true with respect to my 23andme experience.
I am treated at Froedtert Hospital for Dysautonomia and Orthostatic Hypotension.
Through my genetic testing I have been able to see a list of medications and my possible response to them based on my genetics. This is helpful when you are chemically sensistive.
23andme also has an option to keep your DNA completely private and not used for any type of research if you so desire.
I am hopeful that through this process a common genetic link of some type may be found in common with others who have the same diagnoses as I do and eventually new clinical trails or treatments may be developed to help perhaps not myself, but others who are diagnosed in the future.
- Liza W.