Knowledge is power. But a little knowledge can be a dangerous thing. I'm trying to reconcile these two ideas to decide whether learning my personal genetic code would do more good than harm.

I read today about Google founder Sergei Brin's discovery that he carries a genetic mutation that greatly increases his chances of developing Parkinson's Disease. Brin's wife, Anne Wojcicki, is the co-founder of a company, 23andMe, which offers personal genetic testing. For just $399 (which makes it well within reach for many people), the company will analyze a saliva sample to provide an in-depth report on how your genetics influence more than 80 diseases, health-related conditions and traits. You can learn what is encoded on your DNA and what it might mean for your current and future health.

Do you want to know whether you are predisposed to have a heart attack or develop breast, colorectal, lung or prostate cancer? Are you destined to be bald? Have gallstones? Or live a long life? Would you live your life differently if you knew you did not have the heart attack gene? Maybe not be as motivated to exercise? Or if you were a smoker with the lung cancer gene, perhaps you would be more motivated to quit smoking?

When we move away from the population-based risk generalities and to our own very specific DNA, I am not sure which way the psychology will lead most people. On the one hand, knowing which diseases are more likely to develop than others lets you focus on the health-related behavior changes that may get you the most bang for the buck. If you have the genes for venous thromboembolism, you can take precautions on long airplane rides and be more aware of symptoms that need prompt medical attention. Those with several of the nine genes related to Type 2 Diabetes can focus on losing weight and monitoring changes in their blood sugar over time.

Along these lines, a recent study showed that patients with high cholesterol are more likely to be motivated to stay on their medication after seeing an actual scan of their own arteries showing blockage from plaque -- kind of like the medical version of Scared Straight. The only way to get more personally relevant than seeing evidence in your own body of your risk for heart disease is to see what your genes have to say.

On the other hand, the information people receive (and possibly misinterpret) about their genetic inheritance could lead to an unhealthy fatalism that prevents them from taking any action. If it's written in their DNA, what can they do to stop it? Or the absence of a disease-related gene, such as for breast cancer (they test for 2 genes, but not the rare but high-risk mutations in the BRCA1 or BRCA2 genes), may lead to an unwarranted sense of invulnerability and the belief that mammograms are no longer necessary.

Of course, biology is not destiny. But it might be hard not to take it as such if you learn that you are at high risk for developing a potentially fatal disease. You may live your whole life in dread, waiting for the other shoe to drop (that is a strange phrase, isn't it?).

I am reminded of something that happened to me, which illustrates the idea that a little knowledge can be a dangerous thing. Quite a few years ago, I was having back pain and so my doctor had an X-ray done of my back, along with an MRI. In addition to discovering that three of my vertebrae were fused in what was apparently a congenital condition, the MRI showed what the radiologist termed a "syrinx-like cavity" in my spinal cord. So of course I went online, looked up syrinxes and found that they can be a result of a degenerative disease called syringomyelia. It appeared that I would eventually suffer from things like motor impairment, muscle weakness, loss of sensitivity, and chronic pain. I and my family were devastated.

I became an expert on the disease, identified the best course of treatment (surgical implantation of a shunt in the spinal cord) and found clinical trials I could sign up for. Because this is a fairly rare disease, my regular physician and the specialists I consulted with did not have much more to tell me than what I could find myself. The fact that I was asymptomatic was a good thing, but symptoms can come suddenly, triggered by coughing or straining that puts pressure on the cerebrospinal fluid.

I was lucky that one of the world's experts on syringomyelia was based at UCLA, and after what seemed like a very long time, I was able to get a consultation with him. He took one look at my MRI and said that I did not have syringomyelia. The syrinx was just a vestige of a congenital blip in the development of my spinal cord, and would likely never cause me any problem. And just like that, the random discovery of this anomaly that had turned my life upside down no longer meant anything. False positives are always an issue, as they are with technologies like full-body CT scans that are fishing expeditions for evidence of disease.

As more and more people decide to delve into their genetic endowment, like those at the "spit parties" hosted by 23andMe, ethical issues are bound to pop up. I don't think we'll ever have Gattaca-like genetic discrimination, but what happens if insurance companies decide they need to have a look-see at our DNA before they agree to cover us? Genetic testing already plays a prominent role early on in the dating process in some Orthodox Jewish communities, with both parties getting tested and checked against each other to see if they are genetically compatible (i.e., not both carriers of genes for genetic diseases more common among Ashkenazic Jews). Potential couples who may otherwise be perfect for each other may never get together because of that 25% chance of having a baby with a disease like Tay-Sachs or Cystic Fibrosis.

So, what do you think? Do you plan to have yourself and your family tested? Would knowing your genetic code motivate you to take action? Or are there just some things you would be better off not knowing?


Photo Credit: MASH DnArt

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