The Human Genome Project (HGP) is an international project that was coordinated by the U.S. Department of Energy and the National Institutes of Health. Other major partners and additional contributions came from the United Kingdom, France, Germany, Japan, and China. This project was formally initiated in October 1990 and finally completed in 2003. However, analyses of these data will continue for many years to follow.
The goals of HGP were to identify all the genes in human DNA (which is approximately 20,000 to 25,000), determine all of the sequences of the chemical base pairs (about 3 billion) that make up human DNA, store this information and make it available in databases, make improvements on tools used for data analysis, eventually transfer related technologies to the private biotechnology sectors, and address the legal, social, and ethical issues that will ultimately arise as a result of the completion of this project.
Many benefits have been projected as a result of HGP. The benefits from genomic research have potential applications in areas of molecular medicine, energy sources and environmental applications, risk assessment, bioarchaeology, anthropology, evolution, human migration, DNA forensics (identification), agriculture, livestock breeding, and bioprocessing. In addition, commercial development of genomics research will provide U.S. industry with several lucrative opportunities from the sales of DNA-based products and technologies. Overall profits in biotechnology industry are projected to exceed $45 billion by 2009.
In regard to molecular medicine (a branch of medicine that deals with the influence of gene expression on disease processes and with genetically based treatments, such as gene therapy), HGP has provided technology and resources that have already had a widespread impact on biomedical research and clinical medicine. This is being made possible by increasingly detailed genome maps, which have assisted medical researchers in identifying genes associated with several genetic conditions. Clinical improvements will also be seen with more accurate diagnosis of disease, earlier detection of genetic predispositions to disease, rational drug design, gene therapy and control systems for drugs, and pharmacogenomics (the application of a genomic approach to the identification of biological drug targets and interactions). In short, molecular medicine will be defined less by treating symptoms of a disease and more by addressing the fundamental (or genetic) causes of a disease and its pathology.
HGP will also have applications in energy and the environment. Technology initiated in HGP can be utilized in the Microbial Genome Program, which is aimed to sequence the genomes of bacteria useful in energy production, environmental remediation, toxic waste reduction, and industrial processing. Microbial genomics research can be used to create new energy sources (called “biofuels”), to develop environmental monitoring techniques to detect pollutants, to develop safe and efficient environmental remediation, and to develop research for carbon sequestration. In addition, microbial genomics will help researchers to better understand how pathogenic microbes cause disease. Furthermore, research on microbial communities can provide models for understanding biological interactions and evolutionary history.
Understanding the human genome will have a significant impact on scientists’ ability to assess health risks posed to individuals exposed to toxic agents; this is known as “risk assessment.” This will be possible by examining the genome to identifying gene(s) that will increase the likelihood of potential harm. Therefore, HGP can improve the assessment of health damage and risks caused by radiation exposure, inducing low-dose exposures, exposure to mutagenic chemicals, cancer-causing toxins, and reducing the likelihood of heritable mutations.
Our understanding of human evolution and the common biology that humankind shares with all life will be improved by understanding genomics. Therefore, HGP will enhance our ability to more effectively study evolution through germ line mutation in lineages, study migration patterns of different types of populations based on female genetic inheritance, study mutations on the Y chromosome to trace lineage and migration of males, and to compare breakpoints in the evolution of mutations with ages of populations and historical events. Comparative genomics between humans and mice have already showed similarities in genes associated with disease and traits, which is useful in developing research models. The function of thousands of other genes with unknown functions can be determined by additional comparative studies. In addition, the comparison of DNA sequences of the genomes of different microbes can provide new insight in regard to the kingdoms of life: eukaryotes, prokaryotes, and archaebacteria (which is considered and presently classified an ancient life form that preceded and evolved separately from later bacteria and blue-green algae).
In DNA forensics, data from HGP will improve our ability to identify potential suspects whose DNA may match evidence left at a crime scene; exonerate individuals wrongly accused of a crime; identify crime and catastrophe victims; establish paternity and other family relationships; identify endangered and protected species (could be used to prosecute poachers); detect bacteria and other organisms that may pollute air, water, food, and soil; match organ donors with recipients; and determine pedigree for seed or livestock breeds. This will be made possible because any type of organism can be identified by the examination of a DNA sequence, which is unique to that species. To identify individuals, forensic scientists will scan about 10 DNA regions that vary from person to person and use this information to create a DNA profile of that individual (called a “DNA fingerprint”).
In agriculture, the understanding of plant and animal genomes will allow the development of genetic modifications to yield crops that are disease-, insect-, and drought-resistant as well as healthier, more productive, and disease-resistant livestock. An example of the benefits gained would be that disease-resistant crops would require little or no pesticides. This would be beneficial because pesticides can be hazardous to humans, and pesticides are expensive, which adds to the cost of production. Therefore, safer and less expensive food can be grown. In addition, larger and more nutritious fruits and vegetables can be grown. It is also conceivable that edible vaccinations can be incorporated into new food products.
A very complicated science is behind the completion of HGP. In a basic sense, DNA from every organism possesses the same chemical components (i.e., a 5-carbon sugar group, a phosphate group, and a nitrogenous base). An organism’s complete set of DNA is known as a genome. DNA is typically arranged into a distinct unit called a “chromosome.” Each chromosome contains specific regions called genes, which are the basic physical functional units of heredity. Genes contain instructions that encode how to make proteins, which ultimately perform most biological functions. The total arrangement of a cell’s protein is referred to as its proteome.
Each protein has a specific chemical composition and biological function, which are provided by instructions from a particular gene. Many genetic diseases are attributed to an irregularity in the structure and/or function of a protein, which is directly connected to an error in the base pairs of that specific gene. Consequently, a gene with a mistake in its base pairing will yield an abnormal protein, which is manifested by an abnormal physiology. Examples of this would include an abnormal structure in one of the proteins of a red blood cell, resulting in its inability to properly carry oxygen molecules (seen in anemia) or an abnormal protein structure of a sodium channel, which results in the inability of a cell to function properly, causing gastrointestinal and respiratory problems (seen in cystic fibrosis). Research that is geared toward protein structure and function is now becoming the main focus in order to provide insight into the molecular basis of medical health. This area of study is known as proteomics.
How is sequencing of the genome done? In the initial “subcloning step,” the chromosomes are chemically broken down into smaller pieces, which are easier to work with. Next, each piece is used as a template (the template preparation step), which is, in turn, used to generate sets of fragments (the sequencing reaction step) that differ in length by one base pair. The newly sequenced fragments are then separated by a biochemical technique known as gel electrophoresis; this process is the separation step. The final step (the base-calling step) recreates the original sequence of each short piece generated in the subcloning step; this is analyzed by automated sequencers and read by computers (known as bio-informatics), which assemble the small sequences into a long, continuous strand that is examined for errors. The completed sequence is sent to a major public sequence database and made available to everyone around the world.
In the future, technology and genetic bioengineering may merge together and combine with information from the HGP to make it possible to “enhance” the human genome of an individual, thus potentially enriching the gene pool. Of course, this is very controversial and arouses many ethical and religious concerns. This technology is seen in a new area of medicine called “gene therapy,” which is the treatment of genetic disorders, anomalies, or deficiencies by introducing specific engineered genes into a patient’s cells. Presently, this is being introduced as a treatment option for diseases like prostate cancer.
Up until now, a tremendous amount of benefits has been enumerated and discussed, and consequently a typhoon of excitement has been created about a new era to come. However, there are many ethical, legal, and social implications that will need to be addressed in the new “postgenomic” era.
Much concern has been raised as to the fairness in the use of personal genetic information. It will need to be determined who should have access to personal genetic information and how to use it ethically and legally. This will need to be established so that insurance agencies, employers, courts, and schools do not use this information unfairly or discriminate against individuals based on their genomes. In addition, it will be important to decide who will legally own and control this information and what type of privacy and confidentiality will be ensured.
There are also concerns regarding genetically modified foods, as to whether they are safe for human consumption and to the environment or if they will have adverse effects on people’s health. Research will have to be conducted to determine any detrimental effects or health risks associated with consuming genetically modified products.
Many clinical issues will also need to be resolved. For example, how are genetic tests evaluated or regulated for accuracy and reliability? Presently, there is little or no federal regulation in regard to genetic tests in the clinic. Other clinical issues will need to be addressed, such as whether we are prepared for the changes that will take place. It also needs to be assessed as to whether or not health care professionals are prepared to deal with the new genetics in a clinical setting. Ultimately, this may lead to changes in a clinician’s education and certification standards. Also, it needs to be determined whether the public is being prepared to make an educated and informed choice regarding genetic testing and the possible advent of gene therapy.
The new age of gene therapy also conjures up concerns in regard to what will be defined as required medical treatment and what is classified as genetic enhancement. Ethically, should people be allowed to enhance their genomes when it is not medically necessary? And what type of regulations will be set in place? In addition, it is conceivable that only the wealthy may be able to afford genetic enhancement. It may be also conceivable that this could give rise to a superior genetically enhanced upper class and a reciprocally inferior genetically unenhanced lower class. Or will it be possible for genetic enhancement to be equally available? This may create a “separation of class based on the availability of genetic enhancement.” It is also conceivable that this could provide the next step in human evolution, leading to a new form of our species.
Philosophical beliefs will also be challenged as a result of the completion of HGP in regard to ideas such as free will. For example, if an individual’s genome and genetic makeup are determined and mapped, will we arrive at the conclusion that an individual’s genetic makeup dictates individual behavior and choice? If a genome can be altered or genetically enhanced, then there is the possibility that an individual’s behavior may be controllable, negating the tender notion of free will and individuality.
In the future, due to the tremendous benefits that will be provided as a result of HGP, progress should be allowed to continue. However, guildelines need to be provided by educated, informed, and just individuals to ensure that new technology is not used to discriminate against individuals unjustly. Long-term goals should include the development of technology to protect all individuals’ “genetic privacy,” as well as addressing ethical and philosophical concerns. In short, the benefits should outweigh any short-term setbacks.
References:
- Benfey, P. (2004). Genomics. New York: Prentice Hall.
- Macer, D. (2004). The Human Genome Project (Vol. 1). New York: Jai Press.
- Palladino, M. (2005). Understanding the Human Genome Project (2nd ed.). New York: Benjamin Cummings.
- Reardon, J. (2004). Race to the finish: Identity and governance in an age of genomic. New York: Princeton University Press.
