DNA Phenotyping

DNA testing is the latest fad to hit the health market. Companies like Navigenics are selling test kits that will supposedly tell you if you have increased risks for developing a number of diseases like Alzheimer"s, breast cancer, cardiovascular disease, macular degeneration and many more. From there, you can make the appropriate lifestyle changes that will bring your risk back down. Sounds great doesn"t it? Well not so fast, there are real problems with this type of testing. First off, say you have a 20% greater risk for developing Multiple Sclerosis that the average person. That would make you concerned right? Well, according to this article from MSNBC.com, that only would lift your risk from .3% to .5% (3 out of every 1,000 versus 5 out of every 1,000, respectively). This is inconsequential yet the lab highlighted it which would cause unwanted concern for most lay people who are not geneticists or statisticians. Secondly, do we really understand what all the genetic variants mean? Does one abnormality really increase the risk for developing a disease or is it really a combination of interactions that is most important? It is my belief, which is backed by a lot of research and the opinions of a lot of people in the field, that we are truly in the infancy of genetic testing and that claiming that a genes configuration means that you are more likely to develop a disease. We don"t fully fathom all the subtle nuances that make up our genes. Next problem lies in those supposed markers that might indicate you have a lowered risk of developing a disease. Do you then not concern yourself with the possibility of getting sick? Lifestyle and environmental causes of disease are far, far more likely to cause a disease than a supposedly abnormal gene would. Another problem I have is when you use the myopic line of thinking that if you have a gene that increases your risk of developing a disease and turning it off is definitely a good thing. Do we know that by turning off the gene we aren"t increasing the risk of developing another more deadly disease? We don"t. Here is an extreme example of this problem. People with sickle cell anemia, a life-shortening disease actually protects the person with the genetic disorder from malaria. Think of living in equatorial Africa with the high levels of malaria. Many children would have died without the sickle cell protective gene. There are literally thousands of other examples, many we are not sure of. In the case of breast cancer, having the bad gene is one thing, but prophylacticaly removing ones breast is an extreme case of acting on the bad gene news. Environmental and lifestyle choices such as depressed vitamin D, exposure to toxins, smoking, and alcohol intake vastly increases your risk of developing the disease, more so than the gene. If you choose to do these things, do you remove your breasts to reduce the risk of developing the disease? Of course not. Having the gene increases your risk but working to increase your vitamin D3 level, avoiding toxic exposure and detoxing regularly, not smoking and reducing or eliminating your alcohol intake would be more beneficial and would actually lower the risk to those women with the gene. In a nutshell, lifestyle choices have a greater impact on overall health than genetics. This is the concept of metabolomics, but that is a whole other blog.