The scientists’ words sounded impressive last week.

Monday, July 03, 2000

The scientists’ words sounded impressive last week.

Researchers have mapped the entire human genetic code. They have begun to identify and place into proper order the 3.12 billion chemical base pairs present in human DNA.

In the coming years and decades, they hope to "mine" the data already collected and determine how genes work and how they can be controlled.

And, to Dr. Elizabeth Murray, associate professor at Marshall University, that’s the most impressive part.

"The cool thing about the Human Genome Project is anybody can go to the Internet and get the entire sequence," said Dr. Murray, who teaches biotechnology.

Researchers, doctors, teachers, even if they have never sequenced a gene in their life, has the ability, she said.

In fact, progressive years of study that led up to the map’s near completion last week has already been used by scientists.

"The biggest goal is that even a place with a small budget can go and do creative research because the tools (the gene maps) are out there," Dr. Murray said.

And that research can lead to many needed things, whether it’s medical breakthroughs or a just a better understanding of life.

For example, genetic data from the studies will help pharmacologists predetermine people’s response to drugs, Dr. Murray said.

Say federal regulators discontinue a very beneficial drug because side effects can be fatal for a very small part of the population.

"If you can find the gene that tells you who can take the drug and who can’t take the drug, then they could re-release a drug that could really help people," Dr. Murray said.

All they have to do is run a genome test before prescribing, she said.

"The potential is huge and the excitement is almost overwhelming."

That idea is termed pharmacogenetics, and it is only one of many possibilities the Human Genome Project holds.

The project is an international 13-year effort formally begun in October 1990.

The Department of Energy’s Human Genome Program and the National Institutes of Health’s National Human Genome Research Institute (NHGRI) together make up the U.S. Human Genome Project.

The project’s genome maps could be used to cure diseases. It could give patients valuable information about their susceptibility to heart disease, schizophrenia or high blood pressure. It could reveal in detail how an adult human being arises from a single cell, functions through a lifetime and dies.

But it will take years, even decades, before such dreams become reality, Human Genome Project director Francis Collins said last week at a White House briefing.

”It’s the end of the beginning,” Collins said. ”Together we must develop the advances in medicine that are the real reason for doing this work.”

The genes have not actually been decoded but entered, letter by letter, into an enormous computer database. The public effort headed by Collins has mapped 97 percent of the human genome and thoroughly covered, or sequenced, 85 percent. A for-profit rival, Celera Genomics of Rockville, Md., also announced Monday that it has completed 99 percent of the genetic sequence. Celera began its work last fall, using an approach that turned out to be faster than conventional methods.

The announcements mark a significant watershed in biology.

”Today we celebrate the revelation of the first draft of the book of human life,” Collins said.

Scientists involved in both projects intend to publish their results jointly later this year. They will also convene a meeting to share what they do know about how the genes work.

”It is a huge milestone,” said Jennifer Nyborg, a professor at Colorado State University who studies leukemia. ”I think it’s significantly more important than walking on the moon.”

The goal of both teams is to identify within that DNA the thousands of human genes. The base pairs are made up of four types of nucleotides, called adenine, thymine, cytosine and guanine. They are abbreviated A, T, C and G in the scientific description of the genome.

It is the order and sequence of these bases within the 23 pairs of human chromosomes that make up the genetic code.

Researchers are also pursuing gene therapy, which would replace or supplement defective genes with correct copies. The field has suffered several recent setbacks, including the death of a patient last year during experimental treatment. Researchers have also found it difficult to find an efficient way to deliver corrected genes to cells where they are needed; they remain optimistic that effective methods will be found.

But most of the benefits of the human genome are further down the road, including:

– Which genes do what. Genes code for proteins, which do the actual work of the body by building tissues and catalyzing biological reactions. In many cases, a gene will be valuable only when scientists understand what protein it synthesizes and what that protein does.

– How many genes exist. Estimates vary from 30,000 to 200,000.

– The role of ”junk” DNA. Only about 3 percent of the genetic information actually encodes proteins. Another small percentage regulates genetic activity, turning other genes on and off. The remainder may consist of typographic errors that have arisen in the genetic code over billions of years, strings of ”spacers” that increase the reliability of the gene copying process or something completely unexpected.

– Where and when genes are activated. Any given cell only uses a fraction of all the human genes, and which ones are turned on determines what type of cell it is. A heart cell, for example, uses a set of genes that allow it to contract in response to electrical signals. An immune cell uses genes that help it attack germs. A cancer cell turns on genes that allow it to reproduce uncontrollably.

At the news conference, President Clinton said the genetic map must never be used to segregate, discriminate or invade the privacy of human beings.

Legislation currently being sought in Congress would offer such protection.

The Associated Press contributed to this story. On the Net: Human Genome Program: http://www.ornl.gov/hgmis/project/progress.html.