What is genome sequencing?
Genome sequencing is a method in which the genetic makeup of a specific organism or cell type is determined. In sequencing the genome, a great deal of information can be determined such as the likelihood of getting certain diseases or possible allergies. Scientists are interested in this technology because it allows the possibility of diagnosing unknown diseases, detect diseases from the genome prior to symptoms, and advance preventive care greatly.
History
- 1965 – Robert Holley sequenced the first tRNA from Saccharomyces cerevisiae, a type of yeast.
- 1972 – Walter Fiers sequenced the DNA of an entire gene.
- 1977 – Fredrick Sanger found an alternative and more efficient way to sequence DNA called the “chain termination method.” He used his method to sequence the first complete genome by sequencing the genome of the bacteriophage PhiX174.
- 2000 – Massively Parallel Signature Sequencing (MPSS) Lynx Therapeutics (USA) Company launched the first of the NGS technologies, which was later bought by Illumina. This next-generation sequencing didn’t use radioactive material and could produce a higher throughput. However, it sequenced a smaller portion of the DNA
Image credit: National Human Genome Research Institute
As technology continues to develop, genomic sequencing has become cheaper and more accessible. Soon people will have the opportunity to get their genome sequenced for as low as one hundred dollars.
Image credit: PLOS Biology
As demonstrated above, there has been an almost exponential increase in the number of people who have had their genomes sequenced due to the decrease in price. As of February 2021, close to 30 million people have gotten their genomes sequenced.
As this technology advances, much controversy has occurred over the ethics of genome sequencing. What are the pros and cons of sequencing one’s genome at different ages? What are the ethics around getting a genome sequenced? To answer these questions, it is essential to look at sequencing during different stages of life: sequencing while a fetus, from birth to adulthood, and from adulthood onward.
Sequencing the genome of a fetus
Proper Consent
Oftentimes parents do not have a complete understanding of all of the implications and possibilities that come with genome sequencing and therefore they are unable to give their full consent. The solution seems simple, just provide all of the information needed to make the decision. However, the solution is complex because of the certainty and interpretation of the results, meaning, with most results, the implications of the findings are difficult to explain due to their complexity. Often there is information other than what is directly being investigated that presents during genomic testing, creating an additional issue with consent.
Certainty of Results and Information Communicated
Often, certain results can signal significance, however, it is impossible to know with full certainty if the child will ever be affected. Additionally, many genomic sequencing results are currently unable to be interpreted. This complicates things as too much information can be too complicated and lead to minimal understanding, however, not enough information can be seen as withholding information. The consensus tends to be that all information and data that could be acted upon should be delivered to the patient. Nevertheless, what is considered to be actionable is a grey area. Furthermore, results might persuade parents to terminate a pregnancy due to the possible conditions of the baby. This could cause many problems due to the ambiguity of the results and the certainty that the newborns would actually be affected.
This leads to the question of whether uncertain results should be communicated back to the patient. While there are many results with an uncertain level of significance, many results also have a high level of certainty. If there is a disease or disability that has been detected and has the potential to be fixed, is the doctor obligated to do so? The answer may seem obvious to some people, however, there are arguments for both sides. It can be seen as the duty of a doctor to intervene, however, this intervention could decrease diversity and could imply that those with disabilities aren’t “normal”. As of now, the final decision is in the hands of the parents.
Benefits
Although there are many ethical concerns, this procedure has many benefits. The most obvious benefit of genomic sequencing of the fetus is the ability to receive treatment early. Possible disabilities or diseases such as heart disease, cystic fibrosis, and sickle cell anemia could be prevented with treatments improving the quality of life of the newborn baby.
Even if the condition isn’t curable, finding out early on could prevent the condition from worsening. With information about any disabilities, diseases, or abnormalities, parents have the opportunity to plan ahead. This advanced planning often saves money and can lead to less stress. This is especially the case with newly found mutations in the DNA which can result in diseases that do not run in the family which would make them harder to predict without genomic sequencing.
Fetal sequencing can also uncover many of the undiagnosed anomalies missed with ultrasound screening, possibly saving lives.
Sequencing the genome of a child
Proper Consent
The same issues that come up with consent regarding prenatal genomic sequencing apply to this age group as well. However, there is another issue that comes up regarding consent; is it ethical to give the parents the authority to make the decision of whether or not genomic sequencing should be done? Should the child have the right to choose whether or not he or she has their genome sequenced? It is up to the parents to choose the option that is in the child’s best interest, however, there are some conflicts that go along with this. With the choice in the hands of the parents, the child loses the right to not know.
Another issue with consent is whether or not the parent should be able to decide to release the data to be analyzed and used for research. The information belongs to the child, since it is in fact their own DNA, however, the decision is left to the parents.
Return of Results
Another issue that comes up is testing for disorders that don’t take effect until adulthood and have no treatment that could be applied during childhood. Would the knowledge of such a disorder be beneficial in any way or would it just induce stress? The genetics community has decided that testing or returning results of testing children for adult-onset diseases should be withheld. This has been decided in order to respect the children’s autonomy; it would protect the child from unnecessary harm, and there would be no real benefits in testing for adult-onset diseases that have no treatment.
Lack of Autonomy
A problem that doesn’t happen as often is if the parents’ opinion on what is best for the child opposes the opinion of what the health care professional thinks is best for the child, then the child could be harmed. The child does not get to decide whether or not to accept the health care professional’s advice and instead has their decisions made by their parents which could be harmful.
Benefits
Even though there are ethical issues with genome sequencing in children, there are many undeniably beneficial outcomes as well. The most prevalent benefit, especially in genome sequencing for children, is finding out if they have any child-onset conditions. There are over 2,500 genes that are associated with child-onset conditions. The discovery of one of these genes would help prepare the child and the parents to deal with the conditions or it could even lead to a possible treatment of the condition. In either scenario, the overall quality of life would go up and there would most likely be an increase in life expectancy.
Genomic sequencing in children would also help determine if they would have an allergic reaction to different drugs that could be used for treatments. It would definitely be easier to find out a child is allergic to something through a genetic test rather than experiencing an allergic reaction. Not only can genomic sequencing of a child be beneficial to the entire family, but it can also help other children all around the world. This is because as more genomic data is collected, more mystery diseases can be solved, helping others around the world. The video below shows a real-life example of when genomic data was used to diagnose mystery diseases.
Not only can genomic sequencing be used to diagnose mystery diseases, but it can also make the diagnostic journey much easier for a variety of diseases. Instead of going through hundreds of different time-consuming and often painful tests, it is possible to get a full diagnosis from just genomic sequencing. A real-life example of this is shown in the video below.
Sequencing the genome of an adult
The majority of the ethical issues that have already been discussed also apply to adults. If anything, there seem to be fewer ethical issues.
Proper Consent
The issue of making the decision on whether to get genomic sequencing done for someone else such as a child is eliminated since adults are old enough at this point to give consent. However, the problem that resurfaces is whether or not that consent is truly considered consent. This is due to the complex nature of genomic sequencing so even if there is the consent given, it is not informed consent so ethical questions referencing the reliability of that consent arise.
Return of Results
Another issue comes up with what information to reveal to the patient in the results. With prenatal and sequencing in children, this issue would be in the hands of the parents, however, in this situation, the issue is in the hands of the medical professionals. Nevertheless, this problem could be eased by asking the patient what information they want to be disclosed to them before the sequencing is done. Due to the opposing viewpoints in this process, it is up to the individual doctors and companies as to what is revealed since different experts have different recommendations.
Benefits
Similar to the ethical issues for this age group, the benefits are very similar to the benefits of the other age groups as well. There aren’t many different benefits but the one that stands out in most age groups is diagnosis. When someone has health issues, genomic sequencing could offer very precise diagnoses which could help with managing the illness and coming up with treatment options. Genomic sequencing can be used to identify what drugs they should be taking as well which would be more helpful in adulthood rather than childhood.
The video below is a real-life example of genomic sequencing preventing many possible deaths in adults of this generation and the next one.
A long-term benefit that comes out of more genomic testing, not exclusive to sequencing in adults, is that with more genomic data, more correlations between genes and disease can be found, leading to more accurate diagnoses in the future. Whole genome sequencing would be able to look for a much larger array of different conditions than before helping to prevent even more diseases.
With genomic sequencing, there are many possible concerns, such as proper consent, the certainty of results, the return of results, and lack of autonomy. These are just some of the issues that would have to be weighed against some heavy benefits, such as diagnosis of mystery diseases, early treatment, and finding what allergies affect you. Depending on different people’s age ranges and values, sometimes the benefits outweigh the concerns whereas sometimes the concerns are too heavy.
Would you get your genome sequenced?
Albert Nasr is a senior at Mira Loma High School in Sacramento, California. He loves biology because of how even in the most complex systems with so many different intricate processes, everything seems to fit together perfectly. Albert, being eager to learn more about how these complex systems function in everyday situations, was thrilled to take part in the summer workshop at Stanford University.
Apart from biology, Albert is also incredibly passionate about soccer, and he loves trying new foods from different cultures.
