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Gene Therapy Race Is Just Barely Out of the Starting Blocks

CRACKING THE GENOME: Inside the Race to Unlock Human DNA; By Kevin Davies; Free Press; 310 pages; $25

February 12, 2001|NICK OWCHAR

If you think about the genetics of cancer, it's no wonder that chemotherapy doesn't always work. Recent books show how, when a therapeutic chemical hits and damages malignant cells, the cells often ignore their own self-destruct mechanism because of a genetic mutation that has made them "deaf" to this command. That's why some scientists have placed their hopes on creating viral "smart bombs" to open their ears.

And this is also why the fires under such efforts burned brighter after last year's announcement at the White House that the human genome--all 3 billion letters of human DNA--had been figured out. Now, scientists possessed the "language of God" to treat disease. It was "one of those achievements of the human spirit that makes me proud to be human," declared evolutionary biologist Richard Dawkins.

But as Kevin Davies shows in "Cracking the Genome: Inside the Race to Unlock Human DNA," new disease therapies are still a good ways off. And Davies has done a superb job of creating a sizable book out of what's still a work in progress: The mapping wasn't quite complete by the time of the June 26 ceremony (even today, now that the "rough draft" is done, work continues to understand what it means). That premature announcement, he says, helped the U.S. government-backed Human Genome Project save face after lagging behind Celera, its private competitor. The book's contents seem less a form of padding than an interesting survey of the young science of genetics, the basics of DNA structure and a tantalizing glimpse of the ethical perils and technological possibilities awaiting humanity.

Davies unravels the double strands of the DNA's helix for readers, giving us as dizzying--and humbling--a view of the micro-world as the Hubble telescope did of deep space. "The total amount of DNA in the 100 trillion cells in the human body," he writes, "laid end to end would run to the sun and back about twenty times." Just four chemical "bases"--referred to as A,C,G and T--run along the helix in various triplets and combinations, which, when "read" like the 1's and 0's of a DOS program, give instructions for making the thousands of proteins that sustain our bodies.

Every historical breakthrough, this book clearly shows, rests on many shoulders. We learn about the 1920s experiments in which "something" changed nonvirulent bacteria into virulent strains, killing lab mice; a New York immunologist's successful identification of that "something" as DNA in 1943; X-ray images in 1953 of a dark cross-like shape, confirming James Watson and Francis Crick's Nobel Prize-winning model of the double helix; and the push in the following decades to map the human genome.

In 1990, the Human Genome Project started slowly, only picking up speed after J. Craig Venter, a bold bridge-burning scientist, took on the project in 1998 using private funds and untested computational strategies. Davies recounts it all, including the wars waged over gene patents and the feuding between the project's Francis Collins and Venter up to, and since, the White House ceremony.

The book's second half shows that we're not at the brave new world just yet. Davies writes that therapies to "fix" scrambled letters in the DNA sequence--which can create the wrong protein and give rise to disease--haven't yet been successful. But geneticists are more confident that personal DNA profiles will one day be available from your family doctor. And screening for breast cancer genes is already helping many families with a history of the illness.

Davies poses ethical issues, rather than wrestling with them, leaving readers often on their own to wonder about the future. How, for instance, will we create new bacteria to eat toxic waste spills but resist the temptation to create healthier human beings? He describes one geneticist who offers couples a chance to select disease-free embryos and quotes another who speculates that, in another 1,000 years, the human race could be split into two groups: the GenRich and the Naturals.

It's a chilling section, told with a neutral tone, that may cause readers' hearts and minds to clash: If you were presented with a chance to spare your unborn child disease, wouldn't you take it? How will our study of the genome affect arguments about the roots of criminal behavior or sexuality? The final irony is that we entrust the answers to these questions to the same human nature that may be affected by our decisions.

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