Gene Sequencing: What it Can Reveal

You've probably heard of genetic testing, which looks at single genes to determine if someone has an increased risk of a particular disease. But you may be less familiar with genomics, which is the study of someone's complete genetic code. With genomics, scientists map out the exact sequence of a person's DNA to come up with a comprehensive picture of that person's future health risks. Doing a complete genome sequencing on someone is much more complicated and labor intensive than doing a quick gene test, but it can yield much more detailed information about that person.

Two decades ago, recognizing the importance of understanding the human gene sequence, the Department of Energy and the National Institutes of Health together sponsored a project known as the Human Genome Project. Begun in 1990, the project took place over 13 years and involved the sequencing of all 3 billion base pairs of DNA in humans. Scientists have since used the findings of the project to further their understanding of human genes and their implications for disease risk and disease prevention.

Recently, a professor at Stanford University made fresh headlines when he had his research team sequence his own personal genetic code. It took months to do, but the professor ultimately learned that not only was he at increased risk for myocardial infarction, type 2 diabetes, and certain cancers, he also learned that he had rare gene variants that put him at higher risk of sudden cardiac death. He was also able to find out specific drugs to which he would likely be resistant, should he need them, and which therapies likely would work for him.

Genome testing used to be prohibitively expensive. While the cost has fallen sharply over the years, it is still quite pricey and only a small fraction of the population has taken advantage of this technology. Advocates of the practice expect this to change as the process becomes more widely known and accepted. Experts caution, however, that having such a complete picture of a person's health risks means there may be more privacy and confidentiality issues. They also caution that it can be psychologically traumatic for someone to learn that he or she is at risk for certain diseases and conditions, particularly if there's nothing that can be done about them.


Sources: Ashley EA, Butte AJ, Wheeler MT, Chen R, Klein TE, Dewey FE, Dudley JT, Ormond KE, Pavlovic A, Morgan AA, Pushkarev D, et al. (2010). Clinical Assissment Incorporating a Personal Genome. The Lancet, 375(9725)), 1525-1535; Human Genome Project Information,