Understanding the Human Genome Project

The Human Genome Project is a worldwide effort formally initiated in October 1990 which intended to last fifteen years but was completed early in 2003. In general, the project aimed to map the human genome and store the information gathered for further biological and medicinal study. It was directed by Ari Patrinos, head of the Office of Biological and Environmental Research and involved scientists from health establishments from at least 18 of the world’s major nations, one of which being the Sanger Centre, Cambridge in the UK. Other countries involved include the United States, Russia, France, Brazil, Germany, Italy and Japan.

The Human Genome Project was a very ambitious undertaking and had many different aims. The first task was to determine the sequence of bases which code for the four nitrogen-containing bases found in DNA (adenine, guanine, cytosine and thymine) and to identify the estimated 100,000 genes formed by these bases. Another task was to locate all the genes present of the 23 human chromosomes and to have this information stored for future reference and further biological analysis. In order to make these previous tasks easier, scientists also attempted to invent more advanced and efficient DNA sequencing techniques. One goal, which is often overlooked, was to consider all ethical, legal and social issues which may arise from obtaining information about the human genome. These tasks were set out in five-year plans but were often completed ahead of their deadlines due to technological advances.

There are multiple other genome projects which aim to map the genome of different organisms. The Microbial Genome Project (intiated in 1994) aims to map the genome of microorganisms involved in processes such as energy production, environmental remediation, diseases and industrial processes. It is hoped that the study of such organisms may lead to breakthroughs in the development of energy-related biotechnologies, systems that function in extreme environments and drugs involved in killing pathogenic microbes. The Human Genome Diversity Project aims to map the genome between various human ethnic groups in an attempt to analyse the vulnerability of different races to certain diseases and how these populations have adapted. The International HapMap Project aims to create a map of the human genome which describes the genetic variation between humans. This information is expected to be a key resource in identifying the genes responsible for health, diseases and response to environmental factors.

There are several DNA sequencing techniques which were widely used in the Human Genome Project. The first, and most common, is the chain termination method developed by Frederick Sanger. This process involves termination of a DNA synthesis reaction using a nucleotide substrate (di-deoxynucleotide) on a specific sequence of a single strand of DNA, resulting in the production of related DNA fragments. Two relatively new DNA sequencing techniques which have gained shares in the industry are 454 sequencing, developed in the early 2000s and Pyrosequencing, which is essentially the same as 454 sequencing but more accurate and reliable. In 454 sequencing, single-stranded DNA is annealed to beads and amplified. These DNA-bound beads are then placed into wells on a fiberoptic chip along with enzymes which produce light in the presence of ATP. When free nucleotides are washed over this chip, light is produced, as ATP is generated when nucleotides join with their complementary base pairs. The intensity of the light is recorded and is used to determine the number of certain nucleotides present. Essentially, the method allows sequencing of a single strand of DNA by synthesizing the complementary strand along it.

The goals achieved by the Human Genome Project have had a beneficial effect on medical science. Knowing a sequence of bases in gene renders it possible to develop reliable diagnostic tests to test for its presence. By 1999, this process was available to test for genetic inherited diseases such as cystic fibrosis and sickle cell anaemia. This is done by extracting DNA from a cheek cell or a blood sample and determines whether a person is predisposed to the disease. Antenatal tests are also available which test to see if a person’s child will be born with the disease. Some genes which can be tested for play a contributory role to diseases which develop later in life, such as Alzheimer’s disease and breast cancer. Because these diseases are multifactorial, environmental factors play a part in their development. However, knowing whether a patient possesses the faulty gene can help them be targeted by health authorities, have regular screenings and be advised on how to reduce the risk of developing the disease. Knowing the base sequence of a functioning gene may eventually make it possible to replace faulty version of the same gene with the correct functioning one a process known as gene therapy. This has only been done successfully in a few people who have suffered from rare inherited diseases which affect the immune system and a disease known as Severe Combined Immunodeficiency (SCID).

The Human Genome Project has also had an effect on the development of drugs used in curing certain diseases. Once the base sequence of a gene has been discovered, it is possible to determine the protein it codes for since the bases determine the primary structure of the protein. Knowing the 3D structure of the protein allows scientists to develop drugs whose molecules would fit it perfectly and would be much more effective than current ones, producing fewer side effects.

A more unexpected benefit which may arise from the knowing the DNA sequences of different organisms is more detailed study into the theory of evolution. By analysing similarities between DNA sequences of different organisms, major evolutionary milestones (such as the emergence of organelles such as ribosomes and mitochondria in cells) can be attributed to molecular biology. Questions relating to the similarities between humans and primates may also be answered by the data gathered by this project.

While the benefits the Human Genome Project outweigh the negative implications, there are still numerous ethical, legal and social issues which have arisen as the result of mapping the human genome. There are concerns that the tests that have been formulated to test for inherited diseases do not have clear cut and obvious results and some are claimed to be unreliable. Such inherited disease tests which have uncertain results include those which are more complex, such as heart disease, which may be linked to several different genes. In addition, knowing that you possess the gene for a certain multifactorial disease can lead to unnecessary psychological stress and in some cases, discrimination from employers, insurance companies and other when they discover you have a faulty gene which makes you susceptible to a particular multifactorial disease such as breast cancer. There is also controversy on the privacy and discretion of genetic information and whether our personal genome should be freely available. As we have seen, it can lead to discrimination in employment.

On a more philosophical and ethical level, The Human Genome Project leads to question regarding human responsibility and whether we should be handed the responsibility of altering the human genome. This leads to conflict free will vs. genetic determinism, how far does our free will extend? Should it be allowed to extend to altering such as natural and delicate system? Another ethical issue is in regards to the controversial issues with using genetic information in reproductive decision making a process dubbed as making a designer baby’. Should we be allowed to alter the genome of unborn children to give them certain appearances and/or features? In addition, should knowing that we are a carrier for an inherited disease such as cystic fibrosis affect our decision to have a baby? Do we have that right to deny a child’s existence because of this knowledge?

The last implication of the Human Genome Project is the belief that the money expended in the project could be better spent on developing cures for infectious diseases in poverty-stricken countries. These diseases are still widely present over the world and kill thousands and the Human Genome Project is unlikely to benefit those vulnerable to such diseases.

To conclude, I believe that the Human Genome Project is a remarkable breakthrough in medical science and biological study and while there are ethical questions about the use of the information, overall, knowing the map of the human genome has allowed incredible medical breakthroughs in recent years. Processes such as genetic testing and gene therapy have created more awareness about certain inherited diseases such as cystic fibrosis and sickle cell anaemia and have helped countless people alter their lifestyles so they do fall prey to diseases such as Alzheimer’s or breast cancer, which are both inherited susceptibilities. While there are still moral questions to be answered, such as those addressing the issue of altering the genome of unborn children, I believe the Human Genome Project can certainly be identified as a benefit to the world when the data is handled by the right people. Will some of these moral implications still be relevant if inherited diseases become a pandemic and threaten the world? Which would be more important, survival or morality?