In the News: 23andMe and Me: Personal Genomics Coming of Age, Part 1

by Paul Knoepfler, Associate Professor, UC Davis School of Medicine
A revolutionary biomedical phenomenon called "personal genomics" is poised to fundamentally change how you think about your health and your family history.

Your own unique collection of DNA contained in your genome is called a "genotype." Just as we each have a blood type, we also each have a genotype that has important, but more powerful bearing on our overall health and traits. Genomics, which you can learn more about here, is the study of our genotypes at the DNA level.

Our genotypes also contain an enormous amount of information about our family trees. The goal of personal genomics is to mine the depths of our genotypes for nuggets of information that have great bearing, quite literally, on who we are, our health, and our family history going back thousands of years. A major, but not the only, player in this relatively new field of personal genomics is a 6-year-old company called 23andMe.

Before shelling out $299 for this or a related service from another company, possible customers might ask themselves if it is worth it. From my experience, I believe it is not only worth it, but goes beyond money to see health and family history in a new way. Let me explain.

Our genotype tells three main types of important stories about us, and the only way we can understand them is through personal genomics.

Some of these stories are past tense, revealing the histories of our ancestors from whom we inherited all the parts of our DNA that collectively make up our genomes. Other stories are present tense in that they are about us, who we are and what diseases we have. Finally, a third type of story is future tense. These stories tell us about what might be. What might my kids be like? What diseases might I get?

In my mind, information is power and information about our families and ourselves is all the more crucial for us to know.

The very personal treasure trove of information in these DNA stories has for millennia been hidden from us -- ironically, tucked away right inside of us in each and every cell. Personal genomics of the kind that 23andMe conducts has the potential to reveal some of those hidden DNA stories, uncovering remarkable details about our past, present, and possible futures.

Not surprisingly, a growing number of people want to learn the stories of their DNA and to understand what their genomes have to teach them. According to Catherine Afarian, Public Relations Manager, and Dr. Joanna Mountain, Senior Director of Research at 23andMe, who I interviewed for this article, in each year of its existence 23andMe has at least doubled their business.

Over this short period of time, 23andMe has collectively analyzed the DNA of more than 150,000 people. What makes this an especially remarkable achievement is that the company, which has itself grown each year, now has only 80 employees. This team is roughly equally divided into three groups of biomedical scientists, engineers, and support staff.

I took the plunge to see what 23andMe could teach me about my family and myself. Part of my motivation was that I am a genomics researcher myself, but in addition, I was curious if I could learn anything about a major health event in my life.

I was diagnosed with a serious form of prostate cancer two years ago at the unusually young age of 42 (median diagnosis is at age 70). Could 23andMe shed any light on why this happened? I hoped so. You can read more about my experience with cancer in "Do Vulcans get prostate cancer?" and "Should Men Get PSA tests? Yes, but..."

I found the 23andMe experience illuminating in many ways, and every step was very easy. Once you place your order, they send you a small snap-cap tube, you spit into it, and then you mail it back to them.

That's it. A few weeks later, you can go onto their website to start quite literally learning the stories that your DNA has to tell you.

I think of it as a biography written in the letters of our DNA. In my case, my DNA, as translated into English for me by 23andMe, had many stories for me. The 23andMe website is very user-friendly and it divides the types of information from DNA into different categories such as diseases risk, traits, relatives, and so forth. Each area can be explored using its own handy tool.

One of the foremost things on my mind when I got my 23andMe results back was whether there was anything in my genome that could answer the important question of why I got prostate cancer and at such a young age.

Or more simply put "Why me?"

Did my genome have an answer?

I went to the 23andMe website for the very first time not realistically expecting a clear answer to the prostate cancer question. I know as a cancer biologist and genome researcher myself that almost nothing in biology is that black-and-white, but I looked at the results in the "Disease Risk" category with astonishment: Smack dab at the very top of the "increased risk" category for me was "prostate cancer"

I was surprised and impressed. Specific elements in my genome together pointed to my having an elevated risk of prostate cancer. Afarian and Mountain told me that my particular genotype put me in the top 10-20 percent of men in terms of prostate cancer risk. You might ask since I already have had prostate cancer, shouldn't my risk be 100 percent? And why only a seemingly modest 1.82x increased risk?

When it comes to disease risks, genomics in most cases is not about certainties, but rather probabilities. In other words, just as the expression goes that anatomy is not destiny, so too is it true that genotype is almost always not destiny.

Thus, 23andMe cannot tell for sure that you will or will not get a certain disease in most cases.

Instead, it estimates risk, and in my case it said there existed a relatively very high risk for prostate cancer. Often, increased risks are not that impressive in a quantitative sense either. For example, it is not uncommon for risks to be less than 2.0-fold increased or decreased. These are still meaningful in an absolute sense, but how meaningful at an actual health level?

It depends on circumstances. In the case of Stanford Genetics Professor Michael Snyder genomics studies told him he was strongly genetically predisposed to Type 2 diabetes, a disease he fairly rapidly came down with after his genome told him he was pretty likely to get it, but he was so rapidly diagnosed in part because the genome data made him and his doctors test him for blood sugar very frequently.

 In the case of prostate cancer, knowing one is in the top 10 percent risk group might make one more inclined to get PSA tests. Of course, in my unfortunate case, by the time I got my genomic data suggesting I was at high risk for prostate cancer, I had already had the cancer; but for many people the hope would be that genomics data could be obtained and be instructive before the disease manifests.

Stayed tuned for parts two and three of this story in the coming weeks, where I go more into the relative finder and family history aspects of personal genomics, other personal genomics companies, and the future of the field including 23andMe.

Disclosure: 23andMe gave me a free analysis of my genome at my request as I was researching this article on personal genomics. I have no professional/financial interest in or connection to the company.

For more by Paul Knoepfler, click here.