Annually, diabetes costs the U.S. upward of $132 billion, autism costs more than $43 billion, and asthma's toll is $11.3 billion. Spending just $100 million in each of the next 20 years to understand better the origins of those conditions, if it would reduce their burden even fractionally, thus sounds like a bargain. Yet our national leaders now seem prepared to throw that opportunity away in favor of other priorities in the country's $2.7-trillion federal budget.

The program at risk is the National Children's Study, designed to ferret out the causes of a multitude of today's most dire and growing health risks, from autism, asthma and diabetes to violent behavior and childhood cancers. Mandated by Congress in the Children's Health Act of 2000, the study would follow 100,000 American children from before birth--and in some cases before conception--until their 21st birthdays. By signing up pregnant women and couples planning to conceive, the researchers could gather an unprecedented amount of information about the interplay between biology and environment that contributes to the children's development and health. Prospective studies of this type, such as the famous Framingham Heart Study that began in 1948, can represent the gold standard of epidemiological research because they are inherently unbiased. By collecting data about a large heterogeneous population in real time, before disease arises, they can test long-held but unproved hypotheses and amass a trove of evidence for investigators to sift through later.

Between 2000 and 2005 the National Institute of Child Health and Human Development spent $50 million to design and organize the project and to identify a nationwide network of researchers to conduct it. This year the scientists were to launch pilot study centers and in 2007 begin gathering data.

But in his 2006 budget, President George W. Bush slashed funding for the National Children's Study, and in his proposed 2007 budget, he eliminated its funding entirely and directed that the study be shut down. The White House rationale for spiking the project, according to budget director Joshua Bolten, is a need "to focus on national priorities and tighten our belt elsewhere."

Presumably children's health is a national priority, so perhaps the scuttling of the study is just one more gesture in the Kabuki theater of Washington budgetary politics. Presidents cut programs to look responsible, and Congress restores them to look generous. Maybe the National Children's Study is less dead than it seems and will soon have its full funding reinstated. But last year when Congress had the chance to fund the program more substantially for 2006, it declined to do so. That is a worrisome bellwether.

In its goals, scope and outcomes, this ambitious investigation could represent 20 Framinghams rolled into one. Smaller-scale studies might chip away at parts of the targeted health issues, but nothing else yet proposed could take its place. Moreover, the hard job of designing and organizing is already done. Just when we are poised to probe the origins of some of the most devastating conditions affecting American children and adults, it would be a fool's economy to squander the money and effort already spent by killing this effort in its cradle. Attention, Capitol Hill shoppers: Do you know a bargain when you see it?