Genomics: A New Field of Medicine on the Rise

Author: Rushil Dua

What is Genomics

Genomics is the study of the human genome — all the genes a person has, their interactions between themselves, and the interaction of the genome with the environment [1]. This is not to be confused with genetics, which is the study of the gene on an individual level [1]. Instead of looking at the interactions between individual nitrogenous bases found on DNA, and how individual traits can be expressed by individual genes, genomics aims to look at the bigger picture [1]. 

Some may have heard of genomics in the context of gene editing, or certain types of genetic therapies. This is a prevalent application of the field in medicine, and is in fact why the field is growing to be in high demand. The medical applications of genomics will be examined later in this article.

History of Genomics

This should come as no surprise, but genomics and genetics grew up together [2]. Both were conceived with the discovery of DNA and are based on DNA structure and function [2]. The understanding of both fields were deepened through the discovery of the double helix model of DNA by Watson, Crick, and Franklin in 1953 [2]. Genomics started to branch off from genetics in 1977, after Frederick Sanger fully sequenced the genome of the phiX174 virus using a self-formulated sequencing technique [2].

From then on, a large focus of genomics was the sequencing of entire genomes of different organisms, including bacteria, animals, and eventually human genomes [2]. A major breakthrough project, known as the Human Genome Project, was a huge step forward in the field of genomics; launched in 1990 and concluded in 2003, the project allowed geneticists to determine the amount of genes present in the human genome [2]. These findings allowed for the development in sequencing techniques by 2007, which inspired  the 1000 Genomes Project in 2008, wherein 2500 human genomes were sequenced [2]. The understanding of the human genome allows a deeper understanding of genetic diseases, as well as the genetic makeup of humans [2].

There has also been focus on sequencing smaller DNA strands to target specific interactions in hopes to determine how to develop a therapy to treat a given disease [2]. For example, in 1982, the gene that causes Huntington’s disease was discovered [2]. This allowed for the development of a therapy that focuses on eliminating the production of a mutant protein (mHTT), cutting a source of development of Huntington’s disease [2].

Applications of Genomics

Since many genomic techniques focus on editing genetic sequences, the implementation of genomics can be beneficial across a large variety of fields, from medicine to agriculture.

In fact, genomics is already frequently used in the food industry, such as in the production of genetically modified organisms (GMOs). Many think of GMOs in a negative light, following the idea that GMOs are inorganic vegetables which may pose a health risk; however, genomics is generally employed for the domestication of crops, as well as the maintenance of crop health in the case of plants [3].

While genes are commonly considered to control one’s life, it is in fact both nature and nurture which defines how someone will live [4]. For example, the possession of certain genes may mean you are predisposed to a certain condition, but the interaction between your genome and your environment will ultimately decide if this gene gets expressed [5]. This also includes an organism’s diet; the food you eat has an impact on your genome [5]. The interaction between nutrition and the genome is studied in a subcategory of genomics known as nutrigenomics [5].

Another subcategory of genomics is medical genomics: the use of genomics in the field of medicine. One breakthrough which is well known in genomics is the CRISPR method, which stands for Clustered Regularly Interspaced Short Palindromic Repeats [6]. This method is based on (and thus receives its name from) the natural defense mechanism of certain bacteria and archaea [6]. These organisms possess a DNA sequence called CRISPR-Cas9, where the Cas9 enzyme is the substance which performs the “editing” of genetic material [6]. Upon invasion from a virus, a bacterium will synthesize an RNA strand known as crRNA from the DNA to fight the virus [6]. The Cas9 enzyme will then bind to the RNA strand, which will guide Cas9 to the target location to make its cut and subsequently eliminate the foreign genetic material [6]. This genetic strand has been extracted from bacteria and is now used as a gene-editing tool among larger organisms, such as humans [6].

CRISPR, as a gene-editing tool has many applications which effectively edits organisms’ genetic makeup. It can correct genetic defects, or eliminate predispositions to different kinds of illnesses such as Huntington’s disease, as discussed above. Other uses of CRISPR include the treatment of cataracts, cystic fibrosis, as well as the elimination of drug resistance in bacteria [6,7]. CRISPR’s applications do not stop here, however, as it was shown recently that CRISPR may even be applicable in the fight against cancer [8]. CRISPR-LNPs, the employed system, carries a genetic messenger to code for the production of Cas9 to cut the DNA of the cancer cell; however, as this is a fairly new study, there is still much to be confirmed and studied [8].

While it may seem that CRISPR holds many answers in medicine, there are some who disagree with its usage in the treatment of genetic disorders. An example of this is found in the case of “Lulu and Nana”. Towards the end of 2018, a Chinese biophysicist used CRISPR on a pair of twins (given the pseudonyms Lulu and Nana) prenatally to edit a gene which would effectively eliminate HIV’s ability to invade white blood cells [9]. However, there was a large uproar after this was heard and some have even suggested that the researcher is currently in jail, under suspicion of having faked ethical reviews to proceed with his research [9]. Beyond prevalent ethical and moral concerns of CRISPR gene-editing, CRISPR has been found to not be fully accurate [6]. That is to say, some studies have found an efficiency between 50% and 80%, and that CRISPR may cut DNA at incorrect locations, leading to mutations [6].

Current and Future Developments in Genomics

Earlier, it was discussed that the Human Genome Project and the 1000 Genomes Project are considered large landmarks in genomics as they allowed for the first successful sequencing of the human genomes. However, researchers argue that the samples chosen for these projects are not representative of the genetic diversity found across the globe [10]. As such, the National Institute of Health launched the Human Pangenome Reference in 2019 to develop a better understanding of genetic diversity in humans [10]. It is believed  that this will advance personalised medicine, as well as the quality of current knowledge of the human genome [10]. 

There have also been developments in gene sequencing and editing beyond CRISPR. The Deciphering Developmental Disorders project managed to diagnose 40% of the recruited sample, even though previously available methods were unable to do the same [11]. This is a big step forward in the realm of scarcely known disorders, as many without proper diagnoses fail to get the treatment they may require to improve their quality and expectancy of life. As for gene editing, there have been newer methods such as TALENs (transcription activator-like effector nuclease) which are also capable of editing genes [12]. One company, Recombinetics, combines TALENs with CRISPR and claims that they are able to target any given site of a genome [12]. This is significant because CRISPR, as mentioned, is not fully efficient and accurate. If future developments in the field of gene editing and genetic engineering are able to substantially improve accuracy and efficiency, it is likely that molecular medicine will eventually possess the ability to accurately diagnose and treat almost all human genetic disorders.

The path in which genomics is currently headed suggests much about the future of science and medicine. It is possible that we will be able to reconstruct the genetic makeup of our ancestors, and learn more about humanity’s spread across the globe [13]. Medicine will likely transform far beyond what is currently available, allowing a better understanding of the human body, as well as ways to combat disease and cancer [13]. There also exists the possibility that scientists will be able to construct whole new organisms through a DNA synthesis of bringing together nucleic acids at some point in the future [13]. All of these advancements will likely come with ethical, moral and theological controversy, but it is just as likely that these advancements will drastically improve quality of human life and revolutionize our current perspective on organic life.

Editors

Kaz Shuji, Winnie Lui, Rhea Verma

Designer

Web design by Majd Al-Aarg

Additional Credits

Cover photo by National Cancer Institute on Unsplash

References

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