Know your genes, know yourself
A coming era of personal genomics could bring DNA profiling to the masses
J. Craig Venter, the former Celera Genomics president who led one of two efforts to decode the human genome, has a leg up on the rest of us. It seems the genome Celera decoded two years ago was primarily his own. So what? Well, for starters, Venter now is taking cholesterol-lowering drugs to counteract the potentially negative effects of a variant gene he spotted in his own DNA. Now that is personalized medicine.
For those of us without several years and a spare billion dollars to follow Venter's example, researchers are developing technologies that could someday deliver this kind of genetic self-knowledge to the masses. From the string of 3 billion "letters" in our DNA, each of us might learn which diseases we are susceptible to in time to take preventive action. If we got sick, person-to-person variations in our genes would guide doctors in choosing exactly the right allergy medication, antidepressant, or painkiller for us. Eventually, personal genomes could help athletes tailor their training, dieters draw up meal plans, and addicts map out recovery programs. In a couple of decades we might even carry digital cards encoded with our personal gene maps right alongside our medical insurance cards.
Such information won't do much good until scientists learn far more about how subtle DNA variations affect health--and how those predispositions can be overcome. Personal genomics will also require DNA-analyzing technology vastly faster and cheaper than exists today. But the race to develop it is already on.
Genetic tests are nothing new. Patients, prospective parents, and even fetuses can be tested for some gene variants, such as those linked to cystic fibrosis, metabolic problems, and certain cancer risks. But those tests are mostly slow and expensive, focusing on one or a handful of genes at a time. True personal genomics means examining the tens of thousands of genes strung out along the 6-foot length of human DNA. And full genome sequencing, although much faster than it was just five years ago, still takes a laboratory full of machines each analyzing a small part of the DNA, together with computers for stitching the results together.
But now that pioneering projects like Celera's have given scientists a portrait of the human genome, they can begin cataloging the person-to-person variations that help make each of us distinct. And they can set to work on miniaturized labs-on-a-chip that can rapidly scan an individual's genome for those variations.
Four years ago Eugene Chan, now 28, dropped out of Harvard Medical School to take up the quest. Earlier this year U.S. Genomics, the company he founded in Woburn, Mass., patented a process that would expose a person's entire genome to many different fluorescent markers, each designed to bind to a specific genetic variant along the DNA. Then the system would untangle the DNA and run it like a length of videotape past an optical reader on a chip. The reader would detect the presence or absence of each marker, cataloging the person's genetic idiosyncrasies. Within three to five years, Chan says, U.S. Genomics should be able to scan an entire human genome in 30 minutes. But other researchers point out major challenges, including developing an optical reader able to reliably detect the tiny fluorescent markers as they flash past, along with software capable of making sense of the data.
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