The uncoiling, unraveling and decoding of the DNA structure by the Humane Genome Project and the Celera Genomics Group is a magnificent scientific achievement and monumental medical milestone. But what does it really mean to the rest of us mortals?
To begin with, it means much less than most people think, hope or worry. As diagnostic physicians, we’ve been trying to come up with a good analogy. Perhaps figuring out the sequence of the chemical elements in human DNA is like finding a huge pile of ancient document scraps in an unknown language and using computers to help sort out the correct order and position of the symbols. But even when sorted out, how could we figure out what the symbols mean? In DNA, scientists have figured out the ordering of the language symbols but don’t know what most of the message means.
Ancient Egyptian hieroglyphics were in this quagmire until the Rosetta
Stone was discovered in 1799. Although a large number of inscriptions were
known, their meaning was unknown. The Rosetta Stone had the same message
inscribed in three different languages including Greek, a known language,
and also in the ancient Egyptian hieroglyphic writing. The Rosetta Stone
gave Egyptologists a jump start in deciphering the hieroglyphic script. Even
then, it took several decades before the meaning of the Rosetta hieroglyphs
was decoded. Further decades passed before many other ancient documents
could be understood.
In a parallel way, DNA scientists now have 739 megabytes of decoded
human DNA data but have only started to figure out what it means in terms of
normal and abnormal anatomy, biochemistry and physiology. Many discoveries
have been made, but a much larger number will be made in the future.
Although we don’t know the ultimate impact these DNA discoveries will
make in daily medical practice, we believe we get many hints from the
medical impact of scientific discoveries in the past:
When first discovered several centuries ago, blood pressure was only
a curiosity but has become vitally important in diagnosing and managing
strokes, heart attacks and other life threatening conditions.
Blood chemistry measurements weren’t very valuable until the
differences in the values in many different diseases and conditions were
analyzed over many decades.
In the mid-20th century, heart surgery not only faced overwhelming
technical problems but serious ethical questions. Today, these procedures
provide new life for children and adults.
Although initially not appreciated as such, blood transfusions were
the first organ transplants. Subsequent transplants of other organs, such as
kidneys, liver or lungs, were initially more controversial. Unlike blood,
which is regenerated completely by the donor, kidneys and lungs don’t grow
back. Heart transplants continue to raise ethical questions, as the beating
heart has differentiated life from death throughout human history.
By contrast, the discovery and invention of penicillin and other
antibiotics over the last 80 years provided immediate life-saving clinical benefits. While a major scientific leap, such drugs raised few scientific or
ethical controversies, and thus, were rapidly adopted.
We suspect that the future applications of the DNA discoveries will not
suddenly appear but will be gradually folded into the practice of medicine
over time. Ethical questions will doubtless arise, but the possibility of
human cloning or “people farming” remains remote on biological grounds
Even if a human being were to be cloned, the result would simply be another human being carrying the same genes as the gene donor, but a very different person because of different environment and experience. The clones would be similar to identical human twins who are very similar physically but still have their own unique identity and life experience. We estimate that more than 99 percent of future applications DNA research will not be ethically worrisome.
The DNA shuffle will provide ammunition for countless books, movies, TV mysteries and talking heads. How about a new board game for those who really want to take the ultimate memory challenge? In the meantime, the relentless march of medical miracles from this latest discovery will thankfully move on slowly and deliberately. For us, as senior physicians, we hope not too slowly.
Dr. Robert J. Cihak, of Aberdeen, Wash., is president-elect of the
Association of American Physicians and Surgeons, and a board member of Discovery Institute. Dr. Michael Arnold Glueck, of Newport Beach, Calif., has written extensively on medical, medical-legal and disability-reform issues.