Humbled science

Ten years ago two rivals tied in a race for what they viewed as one of the top scientific breakthroughs of all time: sequencing the human genome. One was Francis Collins, who led the National Institutes of Health's $500 million, taxpayer-funded effort to catalog all 3 billion base pairs that comprise human DNA. (Collins is now the NIH chief.) The other, J. Craig Venter, founded Celera Genomics and did the same thing, but with different sequencing technology and private funding.

Both scientists boldly claimed that knowledge of the human genome would revolutionize medicine in short order: "There's at least the potential to reduce the number of cancer deaths to zero during our lifetimes," said Venter in 2000. Collins, speaking to Congress in 2003, predicted that by 2020, "gene-based designer drugs are likely to be available for conditions like diabetes, Alzheimer's disease, hypertension. . . . Genetic information will be used routinely to give patients more appropriate drug therapy, and the diagnosis and treatment of mental illness will be transformed."

Both scientists' predictions were overly optimistic. Collins, in a commentary in Nature this year, maintains that sequencing the human genome propelled scientific progress, but he admits it "has not yet directly affected the health care of most individuals."

Venter was even more candid in a recent interview in the German magazine Der Spiegel: "We couldn't even be certain from my genome what my eye color was. Isn't that sad? Everyone was looking for miracle 'yes/no' answers in the genome. 'Yes, you'll have cancer.' Or, 'No, you won't have cancer.' But that's just not the way it is."

The problem is that geneticists began with too simplistic a view of genetic diseases. They believed that by identifying the genes associated with a condition such as Alzheimer's, they could predict who would get the disease and create a drug to inhibit the gene's activity. But the function of DNA is more complex, and diseases sometimes involve non-genetic factors. Genetic markers don't always accurately predict whether an individual will develop a given condition-instead they often give probabilities ("You have an increased risk for diabetes"). And although pharmaceutical companies have finally developed a few gene-based drugs, such as a tumor gene blocker and a treatment for lupus, medicinal applications have been slow in coming.

Some genomics experts believe the field is just about to turn a corner in offering tangible clinical benefits. But U.S. taxpayers have funded several billion dollars' worth of genomics research over the past two decades and should take away two lessons: A genome can't predict the future, medically speaking. Often, neither can scientists.

'Garbage' out

One of NIH director Francis Collins' 2003 predictions about genomic technology has come true: Several private companies offer personal DNA test kits that make learning your risk for developing Parkinson's, obesity, or breast cancer as easy as mailing in your spit. But the FDA could soon regulate the tests after an undercover investigation found companies giving bogus results. Examples: Different test makers gave contradictory results for one customer's risk of prostate cancer-he was either high risk, low risk, or average risk, depending on which test was used. Some companies even predicted which sports kids would excel in. Experts say that's "complete garbage."