Genomics is a scientific field focused on the study of genomes and their structure, functions, and evolutionary history. A genome is the complete set of DNA that is present in each cell of a living organism. The genome is broken down into individual genes, each of which encodes a specific protein. Organisms have huge numbers of proteins that perform a variety of diverse biological functions. Genes are encoded by a sequence of 4 different nucleotide bases, Adenine (A), Thymine (T), Cytosine (C), and Guanine (G). Mutations or changes in this genetic code can cause defects in protein production that can lead to various disease conditions from cancer to sickle cell anemia. In contrast to genetics, which tends to focus on the functions of single genes, genomics considers the full genome and larger gene networks and often observers variations at the population level. The mapping and modeling of genomes has wide implications for the fields of medicine, molecular biology, pharmaceutical sciences, and more. Advances in DNA sequencing could change the way that many diseases are approached and treated. With the advancement of technology with regard to bioinformatics and gene engineering, genomics will likely continue to expand as a field.
Early DNA Sequencing
After the proposal of the now accepted model of DNA structure by James Watson and Francis Crick in 1953, many efforts were made to find methods to effectively sequence DNA. The first efficient method for sequencing larger pieces of genomic DNA was developed by Frederick Sanger in the mid-1970s and became known as the Sanger Method or chain-termination method. This system combines the use of DNA polymerase, the enzyme that forms double-stranded DNA from a single-stranded template, with dideoxynucleotides that prevent further strand elongation once they are added. This will form strands of different length at each nucleotide position that can then be separated using gel electrophoresis. These fragments can then be assembled into a completed DNA sequence.
Advancements in Sequencing
In 1986, a major advancement was made to Sanger sequencing by the company Applied Biosystems, who optimized the Sanger Method using fluorescent dyes. Now, each dideoxynucleotide was labeled with a different color dye. This allowed for all of the DNA fragments to be run in the same lane and be read by a machine to determine the DNA sequence based on the sequence of the fragments' fluorescence, greatly improving sequencing efficiency. This paved the way for advanced genetic research.
The Human Genome Project
The Human Genome Project is an international, scientific research initiative started in the mid-1980s with the goal of mapping the entire human genome. Researchers sought to determine the DNA sequence and define the function of every gene in the human genome. The project was the largest collaborative biological research undertaking in history and was deemed complete in 2003. The data has been made available to the public and has proven invaluable for uses ranging from determining mutations involved in certain cancers to designing more effective medications by improving gene targeting. Given that there are individual genetic variations present in each person, the Human Genome Project should be considered more of a holistic reference.
Uses of Genomics
Genomics allows scientists to study large data sets regarding gene and protein interactions to better understand how these interactions generate different conditions or phenotypes . The study of this data also allows researchers to better understand how small changes in the genome can cause major effects on the body of an organism. One common subject of study is single nucleotide polymorphisms or SNPs. These are single nucleotide changes at a specific point in the genome that occur at a significant level in a population (>1%) . The study of SNPs can improve our understanding of what sort of effects these mutations can have on a wider population level such as slightly increasing the likelihood of developing a certain kind of cancer. SNPs have also been attributed to contributing to the development of schizophrenia and other forms of mental illness. Other topics of study include epigenetics, which is the study of how mechanisms other than the DNA code itself can generate heritable traits . These can include modifications to the histones such as methylation that change that way DNA is packaged and can affect gene expression without directly impacting the DNA code itself .
Genetic testing, particularly in-home genetic testing, has become a more popular trend. Currently, most genetic tests are unregulated by the FDA and as such, the claims of the makers of these tests have little to no external validation . In 2010, the FDA announced plans to expand their regulation to include all of these tests but that expansion has yet to take place . The FDA regulates genetic tests that are packaged and sold as "kits", which refer to a group of associated reagents that are sold to many different labs. However, they have established limited regulation over laboratory-developed tests (LDTs) in which genetic samples are collected and sent to a single lab for processing . The lack of oversight of these companies could cause issues as more private companies such as 23andMe begin to use these kinds of genetic tests to generate profit. 23andMe is a private biotechnology and genomics company based out of Mountain View, California that focuses on consumer genetic testing. The company has had a relatively turbulent relationship with the FDA regarding regulations, but they seemed to have reached an agreement in 2015. 23andMe is a direct-to-consumer service, meaning that individuals do not need to meet with medical professionals to receive information regarding their genome. While this initiative has been lauded for giving people more autonomy and insight regarding their health, it has also been heavily criticized within medical circles due to the fact that individuals may be misinformed or interpret results incorrectly. Regulations regarding genomic testing will have to balance the needs of individuals, the services offered by companies and the warnings of medical professionals.
As the field of genomics continues to expand and become more ubiquitous in the societal landscape, the issue to designed values comes into play. Phillip Brey, a philosopher of computer and information ethics, emphasizes the concept of embedded values in computer systems. He expands to state that these values may not necessarily be a reflection of the designer. One may apply this notation of embedded values to a topic such as genomics because the intended purpose of genomics was to analyze one’s DNA sequence. The intended value of genomics was to be helpful, but the morally opaque nature has led to grey area with regard to justice. One consideration regarding the justice of accessibility is data sharing. Given that genomic records are incredibly personal, valuable and potentially profitable, regulating who has access will be an important future consideration. Defined standards may help ensure that the ability to sequence and gain insight into the likelihood to disease development is only available to patients and those with whom they choose to share this information with. The security of this information is integral in preventing discrimination which has become more and more of an issue.
As genetic sequencing technology continues to advance, the possibility of having someone's genome become a basic part of their medical record is becoming a reality. Many fear that undergoing genetic testing will lead to discrimination based on their genome, specifically if they are inherently more likely to get disease based on DNA sequence. In 2008, the government based the Genetic Information Nondiscrimination Act (GINA), which prevents both health insurance providers and employers from discriminating (through raised costs, refusal to provide coverage, hiring/firing, etc.) based on genetic information or family history of conditions . Over 1,800 charges have been filed under the GINA as of the end of 2016 with 121 reaching settlements .
- Mandal, MD Dr Ananya. "What Is Genomics?" News-Medical.net. N.p., 20 July 2014. Web. 23 Apr. 2017.
- "Specific Genetic Disorders." National Human Genome Research Institute (NHGRI). N.p., n.d. Web. 23 Apr. 2017.
- Watson, James D., and Francis Crick. Nature: Watson and Crick. London: Macmillan, 1953. Print.
- Sanger, F., S. Nicklen, and A. R. Coulson. “DNA Sequencing with Chain-Terminating Inhibitors.” Proceedings of the National Academy of Sciences of the United States of America 74.12 (1977): 5463–5467. Print.
- Adams, J. (2008) DNA sequencing technologies. Nature Education 1(1):193
- Science Museum. What happened after the Human Genome Project?Science Museum, Web. 23 April 2017
- "Human Genome Project." Wikipedia. Wikimedia Foundation, 22 Apr. 2017. Web. 23 Apr. 2017.
- "Genomics." Genomics | Applications & Technologies | Bio-Rad. N.p., n.d. Web. 23 Apr. 2017.
- "Single-nucleotide Polymorphism." Wikipedia. Wikimedia Foundation, 18 Apr. 2017. Web. 23 Apr. 2017.
- "Epigenetics." Wikipedia. Wikimedia Foundation, 19 Apr. 2017. Web. 23 Apr. 2017.
- "Regulation of Genetic Tests." National Human Genome Research Institute (NHGRI). N.p., n.d. Web. 23 Apr. 2017.
- "Genetic Discrimination." National Human Genome Research Institute (NHGRI). N.p., n.d. Web. 23 Apr. 2017.
- "Genetic Information Non-Discrimination Act Charges FY 2010 - 2016." Genetic Information Non-Discrimination Act Charges. N.p., n.d. Web. 23 Apr. 2017.