J. Craig Venter sparked nationwide excitement in 2000 when his company, Celera Genomics, set out to sequence the human genome independently from the publicly funded Human Genome Project. Celera's "shotgun sequencing" method allowed Celera to complete the mission in only nine months, compared with the 15 years and around $3 billion the Human Genome Project required. But both projects' versions of the genome were in some ways incomplete, having been pieced together from several individuals' DNA and reflecting only half of each pair of chromosomes in a cell—half of an individual's genetic material.
Last week, Venter's institute published the sequence of a complete, individual genome—his own. U.S. News spoke with him about that accomplishment.
Why did you decide to decode an individual's whole genome?
It became clear back in 2000 that by trying to get a "consensus sequence" [a kind of genetic composite] of five people, we were [ignoring] a lot of person-to-person variation. And back then we only did half the human genome. People are comprised of sets of DNA from each parent. If you looked at just the DNA from your father, it wouldn't tell you who you really are. We knew we'd missed a big part of the picture, so we set out to do a highly accurate diploid genome instead of the haploid genome that was done in 2000-2001.
Why did you choose to sequence your own genome?
Partly, it's an extension of what happened back at Celera. At the time, people were said to fear having their genomes sequenced and [made publicly available]. I decided it was not appropriate for me to ask someone else to have his or her genome sequenced and put on the Internet if I wasn't willing to do it myself. Another part of it was straight scientific curiosity. I can't imagine a scientist working in this field not having that curiosity.
What does your genome sequence tell you?
We can get very few yes/no answers out of our genomes. While genetics influence every aspect of our existence, including behavior and personalities, there's no way to truly tell right now what's caused by our genes and what comes from the environment. Even with seemingly simple things like eye color, you can't tell from my genetic code whether I have blue eyes or not. So it's naive to think that complex human behaviors, like risk-seeking, are driven by changes in one or two genes. We need to know the full array of our genome (plus the environment) to try and understand these things.
What will be your genome's impact?
I think this genome sequence will serve as a reference for the start of individualized medicine. This is just the start of this era. We hope that by next year we'll have 30 to 50 additional genomes, and that eventually we'll get at least 10,000. Once we create databases of many individuals' genomes, we can start to sort out nature and nurture and give people information that can help them prevent disease.
Do you envision that someday everyone will have his or her genome sequenced?
Yes. I think it will become part of standard healthcare. It's very expensive to treat chronic diseases. But by knowing [before a disease develops] what we're susceptible to, and then doing things to prevent it, we can lower healthcare costs. Preventative medicine has to be the direction we go in. For example, if colon cancer is detected early— because a person knew he had a genetic risk and was having frequent exams—the surgery is relatively inexpensive and average survival is far greater than 10 years. But if it's detected after symptoms appear, average survival is less than five years, and the cost of treatment can go up from around $12,000 to hundreds of thousands of dollars. An insurance company would rather pay the $12,000 bill than the $100,000 bill. And a patient would rather have the early diagnosis and treatment than the one that comes too late.