Imagine that one day your doctor takes a swab from your buccal mucosa and a few days later tells you that you have a fairly high chance of developing Alzheimer's disease in thirty years. What would you do? Would you start living your life in a state of constant apprehension? You would panic every time you experienced a memory lapse, forever fearful of the clutches of dementia closing in and turning you into a clumsy mass of drool and diapers, as the fog of oblivion washes away the entire world you once knew ? Or would you continue to live your life unchanged, determined to deal with the situation as it evolves into the distant future? Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an Original Essay The above scenario might seem like an exercise in science fiction. But in reality it is a very probable situation that we could find ourselves in, thanks to the immense progress made by medicine, and genomics in particular, in recent years. Next-generation genomic sequencing has been available for some time, but we are finally close enough to making it available as a clinical diagnostic tool for the masses, ushering in the era of personalized medicine. The entire human genome consists of approximately 3 billion base pairs of DNA that encode approximately 30,000 genes. Until now, outside the sphere of research, genetic tests performed in clinical settings evaluate only a single gene, or a small genetic panel of interest, typically relevant to a particular genetic condition in an individual. Next-generation sequencing techniques, however, change this approach quite dramatically. It includes three main approaches, namely whole genome sequencing, whole exome sequencing and targeted sequencing. Whole-exome sequencing examines only the protein-coding regions (exons) of a target genome, while targeted sequencing collects information from a slice of the genome, usually one with high relevance to a specific disease. Next-generation sequencing, when performed on a cluster of genes, classifies them into one of five categories. They are a) probably pathogenic, b) pathogenic, c) unclassified, d) probably benign, and e) benign. This helps doctors and scientists determine whether that particular genetic variant will result in the person or their descendants developing a particular disease. On the other hand, whole genome sequencing allows us to know the exact location of every single nucleotide base pair in a person's genome. By comparing it to other genomes that have been sequenced, we can discover the genetic similarities and differences between different people. It will also shed light on the mysteries of the non-coding segments of the genome. Indeed, whole genome sequencing technology is already being used to determine the relationship of an endogenous population to other populations around the world, thus providing us with important information about the evolutionary history of humanity. The immense amount of information thus obtained from next-generation sequencing techniques provides us with an in-depth understanding of the genetic composition of a particular individual. This directly translates into better diagnostic, prognostic and therapeutic approaches towards the patient, especially in light of his family history and genetic predisposition or resistance to particular diseases. This would then allow the doctor to tailor a treatment plan to his patient's particular needs. The greatest value added by next-generation sequencing, however, is that it allows doctors todiscover rare DNA variants that are solely responsible for the presentation of some rare diseases. This utility has led to astonishing advances in the diagnosis and treatment of numerous new genetic conditions, reducing both the costs and burden of the disease on the person and society as a whole. Next-generation sequencing has also changed the way we look at tumors, shedding new light on hereditary aspects and the various genetic and molecular factors involved in the development and progression of various tumors in the body. Examining a person's entire genome also provides us with knowledge of recessive genes that would otherwise remain latent in the person and instead give them carrier status, leading to a potentially fatal manifestation of a disease or syndrome in their descendants. Whole genome sequencing can also be used to understand the relationships between different genes that lead to the expression of certain phenotypes in a particular person. This would lead to a better understanding of the multigenic nature of different diseases such as hypertension or diabetes and would also help doctors and scientists shed light on the roles that nature and nurture play in the growth and development of a human being. One of the most important roles that next generation sequencing is poised to play in this context is in the field of genetic engineering, where it would allow us to see the different interactions that various genes would have with each other and a modified gene inserted into the genome. This , in turn, would help us create new and improved treatment modalities to combat inherited diseases such as sickle cell anemia or hemophilia. In recent years, next-generation sequencing technology has left the field of exclusive use for scientific research to become a tool that can be used by doctors around the world to diagnose various diseases in common man. This is largely due to the fact that the cost of next-generation sequencing has steadily reduced from millions of dollars per genome to only around a thousand dollars in a very short time frame, and this cost is expected to decline further in the coming years . years. Next-generation sequencing can replace the multitude of single-gene tests currently performed on separate samples with a single standardized test that only needs to be performed on a single sample. This would lead not only to greater effectiveness in screening for genetic diseases and their correlation with the patient's family history, but also to the development of intervention strategies to mitigate, if not eradicate, some genetic diseases that afflict civilization and humanity . Furthermore, the increased accessibility of a technology such as next generation sequencing to the general public means that it can be used in family planning programmes, thus leading to the early diagnosis and prevention of currently incurable genetic diseases. It can also establish itself as one of the gold standard diagnostic modalities for diagnosing and combating different types of cancer. Having a database of genomes would also help us monitor how different, constantly evolving environmental stressors affect humans at the genetic level, and whether these effects result in better or worse survival capabilities for the human species. Next-generation sequencing technology has finally made it possible for doctors to treat not the disease, but the patient; and is poised to play one of the most important roles in ushering in the era of truly personalized medicine. Despite all these benefits, however, there are still numerous obstacles to overcome in translating this near-revolutionary technology into theclinical practice. One of the most important challenges to face is the competence requirement. Most next-generation sequencing technologies require complicated hardware and software and therefore also require a team of sophisticated experts versed in molecular and computational biology, bioinformatics, bioethics, and medicine to accurately interpret test results. Creating such teams would require changes in existing medical science curricula in which the prospective doctor would not only be taught the medical disciplines but also the nitty-gritty of interpreting high-dimensional data. Secondly there is the question of economic burden. Although the cost of access to next-generation sequencing has fallen dramatically in recent years, it is still far from universally accessible. Other diagnostic tests currently used can provide fairly accurate data at a fraction of the current costs of whole genome sequencing, without needing an expert in either medicine or computational biology to interpret the test results. Thirdly there is the issue of data retention. Each whole genome sequenced generates hundreds of gigabytes of data, the storage of which is virtually impossible under the current conditions of the existing healthcare infrastructure. To make this technology a staple of medical diagnosis and treatment, the entire healthcare infrastructure needs to be upgraded, enabling it to manage and sift through such large amounts of data, preferably through an interconnected set of computer clusters and advanced computing modes in the cloud . The fourth is the problem of too much information. The process of whole genome sequencing informs us of the location and status of each nucleotide base pair in a person's genome, including any mutations present. This leads to the problem of misidentification of causative genes, in which insignificant mutations are grouped together with significant mutations as the cause of a particular disease or syndrome. Please note: this is just a sample. Get a custom paper from our expert writers now. Get a Custom Essay Alternatively, significant, causative mutations are often lost in the vortex of incidental findings and non-significant mutations that often occur in genes and have no value in the development of a disease. This is particularly a problem in the case of multigenic diseases such as diabetes mellitus or cancers, where apparently important causal mutations often turn out to be false alarms. Furthermore, sometimes, random results mask much more important results, even though the chance of the person developing the rarer disease is often much lower than for more common mutations that are ignored for the sake of such random results. Finally, there is the issue of ethics and the mindset of the general public regarding the uses and implications of next-generation sequencing techniques. Knowing everything about your genome may not necessarily be a good thing, and situations like the one mentioned at the beginning of this essay may become a common reality. The burden of knowing information about diseases that may not occur may be a burden that many people do not want to bear. Additionally, living in a constant state of apprehension about an illness that may or may not manifest itself in their lifetime could also lead to an increase in mental health issues that have the potential to create many more health problems that technology could solve. Looking from an ethical perspective, next generation sequencing techniques could be used to discriminate against individuals..