Genomics is the science that studies how all your DNA is organized into genes and how those genes function to produce you. Over the past 30 years or so, genomics has told us a lot about how genes define our biology and drive disease development. However, it is only in the last several years that it has become economically and technically feasible for individuals to have their own DNA sequenced, and that the understanding of genetics has reached a point to begin to understand what some of the results mean. For example, DNA sequencing has been used to pair cancer patients with the most effective drugs, and identify and treat an unknown respiratory disease and severe genetic bowel disease in children.
What Does Analysis of Your DNA Really Tell You?
While genomic DNA sequencing has certainly proven its utility, at least for some specific medical applications, the question is, how useful is this information generally? What individual traits, predispositions, and characteristics do features on your own DNA reveal about you? Will sequencing your own genome give you any insight about yourself?
The real predictive power of genetic information is still very limited. Of the millions of unique features in each person's genome, only a small number have been linked with particular traits, diseases, or other characteristics. Even given this limited understanding, there is growing momentum for using individual genomics to personalize diagnosis and treatment in medicine. Paralleling this trend there is also a growth of consumer genomics—companies providing genetic information directly to any individual willing to pay for the analysis. Is this worth doing?
One study looking at data from over 50,000 identical twins indicates that, except for a certain disease with strong genetic links, such as some types of Alzheimer’s, autoimmune thyroid disease, and heart disease, personal genetic data may not be strongly predictive of most medical conditions. However, other researchers have pointed out significant problems with the above study, but emphasize that the predictive power of genomics for individuals is limited.
In fact, while it is clear that our genome certainly defines many aspects of our individual physiology, personality, intelligence, and health, researchers have still only cataloged a small portion of the DNA features that shape these traits, and are just beginning to understand how these interact with our environment to produce their effects. This creates one of the biggest problems with using this information—interpreting it.
What Do DNA Analysis Results Really Tell Me?
Data from DNA analysis simply gives you the A, T, C, and G symbols for the four DNA nucleotide bases. The key, though, is figuring out what they mean when they occur at a certain place in a certain gene. This understanding requires sophisticated interpretation of a massive amount of information, and the interpretation is not static. As new information is discovered about different DNA variations, it affects the interpretation so new findings from the large global community of researchers needs to be noticed and included in analyses.
Of course, companies offering genetic analysis provide some resources to help interpret the results. However, since much of the data involves health related risk assessments, there are liability and regulatory issues restricting the extent of interpretation. Unless you are working healthcare professional, it may be difficult to really assess the implications. Also, a professional perspective might be useful to ensure the accuracy of the company’s interpretations. Actually, most genetic analysis companies work only through healthcare channels, and the FDA has begun investigating the regulatory limitations of companies offering genetic analysis directly to individuals without a doctor’s involvement, such as 23andMe.
Interpreting DNA Analysis Results
To address the interpretation challenge for individuals, third-party resources have also appeared. For example Promethease, based on the SNPmedia database created by geneticist Greg Lennon and programmer Mike Cariaso, and openSNP, an open source resource created by several graduate students for sharing and interpreting genotyping information provide ready resources for individuals that want help analyzing their genomic information.
Meanwhile geneticists have developed Mutadatabase to provide a centralized database documenting all the research findings related to genomic DNA variations to help ensure the availability of the most up-to-date information for interpretation.
You Have Your Ancestor’s DNA
In addition to the health-related predispositions, individual genetic data also provides information about where your ancestry originated. As humans evolved and moved around the globe, small DNA mutations, many of which had no effect, occurred in different scattered individuals. These variations were then passed to progeny and accumulated in geographically separated populations. In 2005, National Geographic launched a massive project to catalog these mutations and use this information track historic human migration patterns.
Genetic analysis enables individuals to map the historic populations that contributed to their genome. According to surveys of 23andMe customers presented at the 2012 American Society of Human Genetics, about 70% of people have genome analysis done because they are interested in these results. Ancestry.com and FamilyTreeDNA have recognized this market segment.
The Coded DNA Oracle
It shouldn't be surprising that people are very interested for find out what's in their genes. If popular interest in psychic predictions and credence in astrology, numerology, palm reading, and related pseudoscience disciplines is any indication, most of us have a strong desire to understand more about who we are and what might be in store for us. Why wouldn't there be similar interest in personal genomics? The type of information you get is not so different than a psychic reading. Genetic analysis, though, is based on results from actual scientific studies so, even if the information is only slightly more informative than a tarot card reading today, future research will likely produce continued incremental improvement of the predictive value.