This story is as intimate as I will get with you. In it, I unzip my genes and give you a sneak peek at my biological destiny. I took three DNA tests from three different DNA testing companies—one from a firm called Navigenics, one from 23andMe, and one from deCODE genetics.

I was so hyped up about getting my DNA analyzed, I didn’t really think about the consequences of having all that information at my fingertips. Perhaps that’s typical of a 25-year-old. I’m working at my first job out of college and living in New York City. There’s plenty in the here and now to worry about: The homeless man deliberately running into me on my way to work. Living on a shoestring budget. Finding Mr. Right.

Some of the test results from the three companies matched up with one another.

Some didn’t.


But I’m getting ahead of myself. Let me tell you what these tests actually test. Our DNA is made up of 3 billion base pairs, with myriad possible sequences of the four chemicals (represented as A, T, G, and C) that form the “instruction book” for a human being, geneticist Francis Collins explains. Sometimes a mistake gets introduced into the DNA sequence. Collins calls these mutations “misspellings”; when a large number of people share the same mutation, they’re known as single nucleotide polymorphisms (SNPs, pronounced “snips”). DNA testing companies use the SNPs to calculate people’s genetic risk of developing complex diseases. Broadly speaking, Navigenics, 23andMe, and deCODE genetics each say that they interpret genetic research gathered from scientific papers, apply it to a customer’s DNA sequence, and deliver the results online. The companies expect that most people will be interested in buying the test, everyone from the average joe to a college student to a politician to me—a half-Asian, half-European girl from Florida.

I’m at risk of developing: sausagelike swelling, ?morning stiffness, inability to identify people’s faces, fat rolls on my stomach, and bloody stools.

Navigenics
I initially heard about Navigenics at a charity event when I spoke to William A. Haseltine, founder and former chairman and CEO of Human Genome Sciences, about genetic testing. The next day, I called Navigenics to ask if I could get tested for free. Normally the cost is $2,500. Product manager Christine Lin said that I could, but only if I could turn around my spit sample quickly. The company was beta testing, and I could be part of the first group.

When the DNA kit arrived in a FedEx package November 11, 2007, I felt a rush. The kit included instructions for how to collect my spit. I harvested the necessary amount of saliva in just five minutes.

But before mailing the spit, I filled out a questionnaire. I penned in basic information like my birthday, address, and details about my ancestry. Interestingly, age and race do not get factored into the calculations—the formula assumes I’m an American of European descent (well, at least half of me is). The fine print that came with the kit stated that I wasn’t going to get medical advice from them and sought permission to use my sample for (gasp) scientific research. Samples are sent directly back to Navigenics’ outsourced lab, Affymetrix in West Sacramento, California. Normally it would take three to four weeks to get your DNA results online. I had to wait two months to get mine because Navigenics wanted to give me the results in person when I visited their headquarters in Redwood Shores, California.

Last January I escaped the bitter bite of the New York winter and flew to California to visit Navigenics and 23andMe. When I arrived at Navigenics’ waterfront office, I was jet-lagged and anxious. Regular customers have the option of calling a toll-free number to talk to a genetic counselor, but I got to speak to one in person (the benefits of being a reporter). I expected the counseling session to be therapeutic—like a scene out of The Sopranos, when Tony goes to his shrink to talk about his anxieties. My genetic counseling session wasn’t like that at all.

Instead, I sat in an office chair with one of Navigenics’ in-house genetic counselors, Elissa Levin, ready to look at my results for the first time. I didn’t want this test to change my life. I just wanted some insight. My eyes glazed over while examining the results on a computer screen: I might go blind (macular degeneration). My joints might ache (osteoarthritis). I might put on weight (obesity). I might have dry skin (psoriasis). I might have diarrhea and constipation issues (Crohn’s disease). I took a deep breath.

Oh, no, I thought.

I have Crohn’s disease.

I HAVE Crohn’s disease?

I have Crohn’s disease.…