It’s in your DNA to read this post

The articles in the NY Times (http://www.nytimes.com/2010/02/11/science/11genome.html?emc=eta1; http://www.nytimes.com/2010/02/18/science/18genome.html?hpw) Ancient Man in Greenland Has Genome Decoded and Scientists Decode Genomes of Five Africans, Including Archbishop Tutu were interesting to me. The cost of sequencing individual genomes has dropped enough to make it possible to investigate individuals anthropologically. Questions once impossible to answer are now clear, and new questions are raised. It’s easy to imagine genome decoding becoming a reasonable possibility for the average person in the not too distant future.

Genes provide the starting material for every person by encoding mRNA that is translated into proteins that make up our cells, tissues and organs. Sequencing genes gives a baseline for each person. How tall could they be? Do they have a high risk of heart disease or cancer? Will they be able to metabolize certain medications? These questions are easily of interest to many people—and their doctors. Instead of wondering if a patient has inherited a familial risk of breast cancer a doctor can look for markers that give information on the patient’s genetic risk. The patient can then be more proactive if the risks are there, or relax if they are not.

There are, as always, a few caveats. Genes do not give an absolute answer but a baseline, as mentioned earlier. Genetically you may be expected to top 6 feet, but if you have poor nutrition in your childhood that potential may not be reached. Likewise, you may not inherit the familial risk for breast cancer but diet, environment or other factors may increase your risk again. And, of course, all this depends on whether we have knowledge of what a segment of DNA does. The whole human genome is sequenced but not decoded, we don’t know what every gene does or how it is regulated. And even when all genes are assigned functions we still need to investigate how they all work together. People are complex!

So what’s all the hoopla about if genome decoding doesn’t answer any questions? Well, it does answer some questions. Years ago if a doctor wanted to administer warfarin, a blood thinner, he would assess the patient’s age, gender, weight and other physical attributes and pick a dosing range to try. This was potentially dangerous, but better than leaving a patient untreated. Now a simple genetic test can give additional information, is this person, in their best of health, able to take warfarin or not? This one piece of information has greatly reduced the risk associated with treatment by providing a more complete picture of the patient allowing faster treatment with less risk. Just as the genome of the ancient man allowed investigators to see his face for the first time genome decoding in medicine can allow doctors to get a big picture of a patient without relying solely on specific diagnostic tests or general inferences based on age, ethnicity and basic health. So many illnesses have the same or overlapping symptoms that any indication of what is happening in an individual could make a world of difference. Diagnoses would occur sooner and after fewer tests (lower

cost!) and with greater confidence.

This means a lot to anyone who’s been through a grueling diagnosis period but it isn’t what makes the news. I would personally love to know more about my ancestors. Where did my family originate? Where did my hazel eyes come from? My migraines? My laugh? As we uncover all that the genome encodes I can only see this field as getting more and more exciting. What is genetic and what is environmental? All the “It’s in my DNA to eat this brownie” comments I’ve long suffered as a biologist could finally be settled. Is it in our DNA to crave certain foods to meet nutritional needs? That seems likely. Is it in our DNA to buy fabulous shoes? Perhaps that is less likely to be substantiated (I’ll have to find another excuse). Our understanding of ourselves will be broadened impacting everything from casual comments in sitcoms to medical care and disease diagnosis.

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