Wellness Wednesday: DNA testing

Your DNA is the code to your programming. It is literally your genetic code. It determines your physical makeup, from appearance, to reproductive potential, to disease states. It may also determine certain hardwired aspects of temperament and cognition. Wouldn’t such information be useful for maintaining health and curing disease ? The answer is of course yes. However, the science of the use of DNA for medical purposes is still in its adolescence if not its childhood. 

DNA (deoxyribonucleic acid) is made like a set of modular children’s toys, K’nex for example. The subunit is a pair of tiny molecules called bases which bind to one another to make a base pair. These are held in a long structure like rungs on a ladder, and this ladder itself bunches and curls depending on the particular molecular sequence of base pairs. A certain series of base pairs codes is a gene for the manufacture of a certain animo acid, and strings of amnio acids are the proteins of which we are made. One famous gene mutation is BRCA, which allows breast and ovary cancers to form much more easily. Another is the gene for ALS ( Amyotrophic Lateral Sclerosis) or Lou Gehrig’s disease, which afflicts Stephen Hawking. 

DNA contains the keys not just to disease, but to health as well. Understanding DNA can help us understand any inborn vulnerabilities to disease in time to take action against them. Understanding which genes go with which diseases may help us come to understand how diseases are caused, and thus, how to cure or mitigate them. The vast majority of human genetic material, also called the human genome, is not understood. However we all have DNA, and we all have a health history, even if all that it says is that we are healthy.  Just think: If we had lots of people record their health history, and the same large number of people sequence their genome, we could use modern computing power to look for patterns between the clinical histories and the DNA. 

DNA tests are now sold direct to consumer (DTC). People are using them to search for their ethnic heritage. This is an imperfect science, and it can only narrow it down to a continent level. Some people use DNA tests to find long lost relatives, but results depend on your long lost relatives having been tested as well. 

I have been thinking about giving my family members the gift of DNA testing. My initial thought was simply to throw our data into the big pool, and add to the collective accumulating accuracy of DNA and disease correlation. It was also my hope that in the process, it would be useful in the future, when hopefully, health enhancing measures could be taken based on a person’s specific DNA profile. 

There is another kind of DNA testing which I should mention for completeness. It is testing for specific genes, and not just testing to view the whole genetic code. Physicians and researchers test for specific genes when a person’s family history is strong for a certain disease process, say colon cancer. If the unaffected relative tests positive for the risky gene, preventive measures may be able to be implement to help them avoid the disease. Genetic tests can also be done on tumor cells themselves to determine what treatment is the absolute most targeted for the specific tumor cell type. This is becoming the norm when treating breast cancer. This helps both improvement in outcomes and decreases side effects of treatments not likely to be helpful. 

In doing the research for this post, I have discovered some good advice. First, it is important to think about why you want this information. Do you really want to know about long lost relatives ? Do you really want to know your ethnicity ? What if it is not as you expected ? What if you discover a gene for a bad disease that you do not already have ? 

There are several companies that do DTC DNA testing. I found a good chart which details some of the differences. 




Some systems of testing, analyzing and reporting are better for genealogy, and some are better for medical care, and still others are best for research. Some tests go deeper, and research paternal or maternal family lines, but this requires analysis of the X and Y sex chromosomes, rather that just the autosomal chromosomes. 

All of the tests are expensive, ranging from $79 to over three hundred. My research has raised more questions that it has answers. I plan to speak to our genetics counselors at our hospital to see what they think and I will get back to you about what they say. 

Meanwhile, it is Thanksgiving week. It is a good time to think about being grateful for what you are and what you have in the present. You may be coded by genes, but that is not the whole story. Our genes are not a static set of molecules. Instead, they switch on and off like the holiday lights that people are putting up this season. Additionally, a lot of this gene regulation depends on lifestyle choices. This is where we can leverage our health habits to make the most of the genetic cards we have been dealt. 

Happy Thanksgiving 


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