The Human Genome Project

Sara L. Crowston

Copyright 1999

On the brink of the 21st century, genetics is paving the way into a brave, new world where the discoveries being made will bestow upon us tremendous powers and possibilities that are restricted only by our imaginations. Many things long considered "science fiction" are well on their way to becoming reality. Advancements made by the Human Genome Project give us the ability to alter our own destinies along with those of our descendents. However, along with the benefits of increased control over our lives come the uncertainties: Will humankind choose to draw boundaries in regards to genetic choices? Where will those boundaries be? How will this affect our future? Could our deepened knowledge of the power of genetics threaten the biodiversity essential to evolution? Would we, in essence, be "playing God"? One thing is certain- life, as we know it, will never be the same (Rayl, 112).

Before one can speculate intellectually about the benefits and uncertainties of genetic study, it is important to understand how we, as humankind, have reached this breaking point of science. The HGP began in 1990 as a 15-year project coordinated by the U.S. Department of Energy and the National Institutes of Health. It is expected to be complete by 2003, two years ahead of schedule, due to rapid technological advances. The overall goals of this project are to catalog the estimated 80,000- 100,000 genes in the human DNA and to determine the sequences of the 3 billion chemical bases that make up the human DNA. This new information will then be stored in databases, as geneticists then develop tools for its analysis. Finally, the HGP is to address the ethical, legal, and social issues that may arise from the genetic research (

The basis for the HGP's study is the genome, which is basically the master blueprint of an organism. Genomes are complete sets of genetic instructions, determining who or what a specific organism is to become. It is already known that the human race has a shared heritage with other life forms on the planet, but, as the HGP has now proven, the overlap among species at the molecular level is more profound that even Charles Darwin might have guessed. It is estimated that we share 90 percent of our genome with rats, 98 percent with chimpanzees, and around 99.9 percent with other humans. It is this minute .1 percent that serves as the complete basis for human differentiation.

In order to study any genome, one must probe into the microscopic world of cells. We humans have trillions of cells, each varying in size, shape, and function. However, all human cells are designed in the same basic manner, with a central nucleus containing long, thin thread-like structures called chromosomes. Under normal conditions every cell has forty-six chromosomes except sex cells, which have only twenty-three (but combine with another sex cell to produce the new 46-chromosome-per-cell progeny). During cell division a chromosome displays two identical arms called chromatids, which are tightly coiled strands of DNA and associated protein molecules. Many scientists speculate that if the entire DNA in one cell were laid out end-to-end it would stretch out to about 6.5 feet, and if all the DNA in the average human body were spread out, it would extend for an astonishing 10 to 20 billion miles.

Each strand of the DNA's double helix is a chain of sugar and phosphate molecules, connected to the other strand by rungs of nitrogen-containing chemicals called bases. There are four bases in DNA- adenine (A), thymine (T), cytosine (C), and guanine (G). The pairing of these bases are adenine with thymine, and cytosine with guanine. The human genome has roughly 3 billion base pairs, which denotes the genome size.

More generally, genes are segments of DNA with a specific sequence of nucleotides, which consist of the instructions needed for assembling various amino acids into certain proteins. Codons, which contain sequences of three DNA letters, or triplets of bases, synthesize the addition of specific amino acids to the cell proteins. A triplet of DNA letters will usually code for the same amino acid no matter in what type of organism it appears. These triplets act as stop signs in determining the end of a protein. These codons, then, identify the different amino acids required to make particular proteins and form series, which make up the genetic code. In turn, proteins comprise and control cells' activities by regulating their expression and guiding their functions. All of these cellular actions and processes make us who we are, each a unique variation of the human theme.

Then, the protein-coding instructions from the genes are transferred indirectly through an intricate communication system involving messenger ribonucleic acid (mRNA), which is comparable to a single strand of DNA. To be expressed, another strand of RNA is constructed via transcription from the DNA template in the nucleus. The mRNA is transferred from the nucleus to the cytoplasm to function as the template for protein synthesis.

As of yet, scientists believe that only 5 to 10 percent of the genome is made up of protein-coding sequences, known as exons. Introns, on the other hand, are mixed in with the many genes and exhibit no coding responsibilities, but can regulate the on and off function of genes. These intron sequences may serve some biological function, but at this time, this function is still unknown. Up to 75 percent of the DNA that lies between genes is referred to as "junk DNA," because scientists cannot determine a function for this material.

Even though geneticists have provided us with all of this information about cells and cell functions, one large, looming mystery remains: precisely how is it that the trillions of cells in a human body know what to do at their point of conception? For example, how does a muscle cell know that is it supposed to develop into a muscle cell? The answers to these questions remain the greatest mystery in genetics (Rayl, 112).

Controversy surrounds the Human Genome Project. On one side, the HGP will provide humankind with many benefits including improved diagnosis of the disease, earlier detection of predisposition to disease, gene therapy, and pharmacogenomics "custom drugs" ( Gene therapy offers the potential of conquering cancer, generating new blood vessels in the heart, inhibiting the growth of tumors, stimulating the growth of new neurons in the brain, and possibly even resetting the genetic code which causes the cells to age (Rayl, 112). Pharmaceutical companies will be able to tailor-make drugs, using an individuals genetic profile, to suit their particular condition. This will help to fend off drug resistance and lessen the unwanted side effects of current therapies. It will potentially decrease the costs in health care (,3266,20825,00.html). Among the other benefits of the HGP, crime fighting is set to take a great leap forward. The FBI, along with other law enforcement agencies in other countries, already has databases where gene-prints of criminals are logged. Clearly, criminals will always try to elude law enforcement, but forensic science is making it much more difficult for them to hide (Rayl, 112). DNA forensics identifies potential suspects using evidence left at crime scenes, exonerates those wrongly accused, enables the identification of crime and catastrophe victims, and establishes paternity (

On the flip side, the outcome of this tinkering with genes is unknown. There may be a loss of biodiversity, which makes life so rich and abundant (Rayl, 112). All this information may increase anxiety and bring unwelcome changes. We must also think about the fact that the information we are receiving is likely to be incomplete ( The validity and benefits of genetic screening need to be established. Also, patients need to be educated and counseled before and after the genetic testing. Patients need to determine first, if they want to know and second, what they are going to do with the information because there may be no treatment for whatever they uncover ( Johns Hopkins University was forced to abort a study of inherited colon cancer in 1998 because the gene test purchased from a commercial laboratory failed to identify many of the cancer-causing mutations (Star Tribune, 21 Sept. 99).

As of yet, there are no laws governing the use of genetic information. When not handled properly, this information could threaten us with discrimination by employers and insurers. The HGP itself guarantees no cures, quick fixes, or detailed understandings ( "All this science is going to be the biggest threat to civil liberties we've ever had," said Craig Venter, head of a privately funded project to decode the human genome (,3266,20825,00.html).

One major controversial issue dealing with genetics is this: who gets to decide the "good" genes from the "bad" genes? Is it appropriate to treat a crippling disease with gene therapy, but not all right to alter the genes influencing sexual preference? Genetics in the new millennium will inevitably modify the world, for better or worse, and in some cases it may be our only hope (Rayl, 112).

My personal opinion is that the Human Genome Project, when completed, will be a fantastic tool in helping to create a better quality of life on this planet. It will give us the potential to find cures for diseases and lengthen our lifespan. Along with these health benefits, the advances could possibly deter people from committing crimes because it is rapidly becoming more difficult to get away with crimes. The HGP has been well documented with new information being made publicly available daily. There is participation by both the private and government sectors allowing for more competition and faster results. With something as controversial as the HGP, ethical, legal, and social issues are bound to arise and at the start of the project there were funds allotted to dealing with these issues. This project has been well constructed and will redefine life as we know it.

The HGP is opening new doors never thought possible. It will create vast amounts of knowledge, which will take years to sort through. We, as a society, must agree upon a set of rules and standards that will govern the ethical, legal, and social issues surrounding the final outcome of the project. Clearly, we must do it quickly.


1- Rayl, A.J.S., et al. "Genetics in the New Millennium." MINNESOTA MONTHLY. Aug., 1999:112- 124.
2- Human Genome Project Information. Obtained 20 Oct., 1999:
3- "The Future is Now." TIME magazine international. 8 Feb., 1999:VOL. 153 NO. 5. Obtained 20 Oct., 1999:,3266,20825,00.html.
4- Associated Press. "Unregulated gene testing can be faulty." Star Tribune. 21 Sept., 1999.
5- Holtzman, Neil and Shapiro, David, et al. "Genetic Testing and Public Policy." British Medical Journal. 14 March, 1998: 316(7134). Obtained 17 Nov., 1999:

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