10/06/2006 01:25 pm ET | Updated May 25, 2011

The Trouble With Genes

It's amazing to realize that nobody really knows what a gene is or how it works, even though the word 'gene' has become the miracle of the hour. Almost every bit of important research in biology and medicine over the past decade has centered on genetics. After the successful mapping of the human genome, we were told that an enormous range of disease will prove curable through gene therapy. Any layman would be justified in believing that genes will end every scourge, bringing the end of cancer, diabetes, and coronary artery disease.

But why stop there? Genetically engineered foods promise corn crops that are immune to pests (literally carrying their own pesticides inside the corn cell), trees that grow as fast as grass (thanks to replacing a slow-growth gene with a fast-growth one), and rice with built-in vitamins. Thus genes will end malnutrition around the world, once we get over certain glitches and fears about tampering with Nature at such a fundamental level.

It comes as a splash of cold water, then, to realize that science doesn't really know what the all-powerful, all-promising gene actually is. This sounds like a rash claim, but the mystery is there for all to see. Time magazine's latest issue discusses this topic in What Makes Us Different?

--No one knows how genes make inanimate chemicals like hydrogen, carbon, and oxygen come to life.
--The ability of DNA to replicate has never been explained.
--We don't know how genes time their actions years or decades in advance.
--Having mapped the sequence of genes, we don't know what the sequence means, only that it exists.
--Having found out that mice share 90% of human genes and gorillas over 99%, we can't explain how the tremendous differences between species should come down to such a tiny fraction of the genetic code.
--We can't explain why people with the same genes (identical twins) turn out to be different in so many ways as they grow up and age.
--We don't know why over 90% of genes are inactive at any given time.
--We don't know why evolution developed genes that cause cancer, and why such genes weren't weeded out after they appeared.
--We don't know if genes cause or prevent aging. In the same vein, we don't know if they cause or prevent cellular death, since there is evidence that they do both.
--We haven't unraveled the significance of the space on the DNA strand, even though the blank spots in our genetic code may be just as important, if not more, than the genetic material itself.
--Genes respond to the outside world as well as to behavior and thoughts, but we don't know how or why except in the most general terms.

That's an awful lot of mysteries hanging around. None of them represent a novel, rebellious, or skeptical point of view. Only the most gung-ho geneticist would claim that any have been solved. The public reads about genes in glowing terms, and yet only a handful of gene therapies have actually cured anything. Last month, for example, researchers admitted near failure after implanting insulin-producing cells in diabetics. A few years ago such cells were used in rats that suffered from induced diabetes, and the rats could be weaned their insulin shots because the implanted cells took over the function inside their bodies.

Hope arose that the same would work in humans, but the problems were many-fold. Some subjects got relief but had to go on insulin after a year or two. The implanted cells took but only for a while. Other subjects had too many side-effects. Others couldn't tolerate the various drugs to prevent tissue rejection. Such drugs, if the experiment had worked perfectly, would need to be taken for life.

Suddenly, the promise of genes looks a lot more murky. Tissue rejection and side effects are critical in medicine. Not to mention the inexplicable way that some people simply don't respond to a given treatment without any explanation (call it the anti-placebo). Tissue implantation to prevent Parkinson's disease and other conditions has run into the same difficulties.

A responsible scientist would have to admit that genetics at present is tinkering with Nature without full understanding of the results. Hanging over the whole field is the shadow of the atom bomb, the last catastrophic mistake of science. The atom bomb, to look at it with a cold clinical eye, was beautiful physics that had horrendous human consequences--and still does.

Nobody wants genes to turn into a biological bomb. I am not suggesting that it has. But with so many mysteries hanging around, it's foolish to plunge into genetics as if we've arrived at the promised land. The downside of gene therapy is that it will only lead to more drugs and enormously higher prices, while at the same time the potential for mind-body treatments and prevention--things that entail no drugs, no tissue rejection, and no side effects--withers on the vine.

That part of the story is already grim. Americans consume more drugs every year and ignore mind-body alternatives and prevention. Such is the official record, and unfortunately, the rise of genes, which have yet to manifest any miracles, is already luring us away from using our own mind and body as healing agents.