Benefits Of Whole Genome Sequencing

We all are made from the information coded in our genes. Whole genome sequencing is an emerging lab process which reveals the complete DNA sequence or make-up of an organism at a single time, thus enabling us to understand different variations within an organism, as well as between different organisms with precision.

The very first Human Genome Project was started in 1990, and completed in 2003. Human genome sequencing has become much more efficient nowadays and a person’s sample can be sequenced in just a matter of few days. At present, most genetic testing focuses on one or a couple of genes instead of the whole genome.

With its declining cost, genome sequencing is being pursued by more and more people. This helps doctors to predict how an individual will respond to a particular treatment. The doctor may study an individual’s unique genetics to look at genes involved in drug metabolism while deciding any drug dosage. This will thus help to develop personalized treatment plans for everyone in the future.

The Impact Of Whole Genome Sequencing (WGS) On Healthcare

The information obtained via whole genome sequencing can help to create a more complete clinical picture of a patient’s conditions. A good example is a recent study that was conducted on 188 families with a genetic history of brain developmental disorders, such as autism, intellectual disabilities, and epilepsy. Researchers initially screened out the families with obvious gene mutations related to the disorder, leaving 118 other families. When the genes of all the individuals from 118 families were sequenced, the scientists found that there were certain gene variations which the affected family members had but others didn’t.

In other words, diagnosis based on WGS suggested a different condition than the medical records. The study found that almost 10 percent of the cases of the brain and nerve disorders were misdiagnosed, thus concluding that genome sequencing will be a more reliable diagnostic tool to understand and treat a whole range of genetic diseases.

Whole-Nation Genome Project: Iceland

Iceland became the first nation to sequence the genomes of its entire population. This helped researchers to identify genetic mutations linked to a number of diseases like thyroid disorders, liver disease, Alzheimer’s, and cancer, and also focus on knockouts (when a working copy of a gene is missing) which are considered to be valuable in understanding the pathway to any disease in individuals.

The study showed that there were around eight percent of Icelanders with knockouts although it does not mean that all of them are prone to any type of disease. There is some level of built-in redundancy in the human genome that allows some genes to lose their function without impacting a person’s overall health. This also explains why a particular disease can make one person sick while another person may remain unaffected by the same condition.

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Why Whole Genome Sequencing?

With the growing demand and efficiency of the genome sequencing process, scientists are exploring more and more options where whole genome sequencing can help humankind. Some of these are:

• Understanding the genotyping of cancer cells, as in, which genes are misregulated and what type of chemotherapy will work best for a patient. This process will expose the patient to less toxic treatment as the root cause is known and treated.
• Traditional genetic testing looked only at the common genes that caused trouble. But there were certain unknown genes too, which were recently identified as contributing to a particular disease state.
• A study of a patient’s genome sequencing will help in creating personalized treatment plans to treat a disease. There may be a case in which not only the mutant gene is responsible for causing a disease, but also other genes in the genome.
• Any lifestyle or environmental changes that may affect genetic predisposition may be identified and moderated.
• It can be used as a proactive measure to identify any disease which a person can be at risk in the future and to take necessary actions.
• Whole genome sequencing can be used as an industry tool to monitor emerging pathogens, determine the persistence of pathogens in the environment and as an indicator of antimicrobial resistance.
• Whole genome sequencing also identifies the likelihood of an offspring having a genetic disorder before conception and during the prenatal period.

Limitations Of Whole Genome Sequencing

We know that the whole genome sequencing has lots of benefits in store for all, but with all these benefits come a few limitations too:

• Lack of information: The role of most of the genes in the genome is still unknown. Thus a lot of information which may be present in the genome tracker is still unusable.
• Untrained medical staff and technicians: Even in countries with advanced medical care, most medical staff and technicians are untrained in genome sequencing and are unaware of how to interpret genomic data. The technology involved in obtaining the whole genome data is rather complex.
• Policies for privacy: A genome sequence test can provide a lot of information about an individual. Though the tests are being conducted, the policies to maintain the privacy and safety of this information are still lacking.
• Risks of too much of information: Sometimes genome testing may give you information that is not required. For example, when a person performs genome sequence testing to determine an effective treatment for his existing disease, the researchers may find out about an increased risk of disease for which treatment is still not available in the process. Preliminary studies demonstrate that many patients would rather prefer not to know such information. This is one of the whole genome sequencing aspects for which neither researchers nor policy makers are prepared to provide clear-cut recommendations yet.

As research continues and our understanding of genome improves, the value of individual DNA sequencing for diseases diagnosing will increase exponentially. But in developing the best practices, it’s important for all the stakeholders in relevant research fields to set up a structure and establish guidelines with regards to clinical utility, consent procedures, handling of unsolicited findings, security of information and variants with uncertain clinical implications.