Life Science Research: DNA Sequencing
DNA sequencing is the single greatest scientific breakthrough to have occurred in the world of bioinformatics and genetics. Determining the order of nucleotides in a DNA sequence has opened up numerous doors in preventative health care.
Patients today can receive a personalized map of their genetics from online test labs for less than $200. Labs like 23AndMe.com answers question on hereditary conditions and predispositions to illnesses. (Read an in-depth review of their Health and Ancestry DNA test here: https://www.myfamilydnatest.com/23andme-review-health-ancestry-dna-test/)
Recent advances in DNA testing mean that lives can potentially be saved if researchers catch these links and red flags quickly.
Improving The Sanger Method And Moving Forward With DNA Testing.
The original method – Sanger sequencing – was revolutionary in its time. It provided answers and options where there had been none. However, modern genetics needs to evolve to meet requirements and expectations. The Sanger method, while beneficial, had become laborious and expensive. The time had come to speed up the process to make it more cost-effective and efficient. The first step was automation. This simply uses the same method through a faster autonomous system for a more efficient process.
The other of these recent advances in DNA testing is next-generation sequencing – often called next-gen for short. Next-gen sequencing has some potential benefits. The first is the type of DNA that can now be a sequence. The process can now sequence all of an individual’s exons (protein-producing DNA). This whole exome sequencing will identify any potential problems with this vital area of DNA. Many disease-causing mutations or know to originate here, so there is a better chance of researcher looking in the right area.
Another benefit of this whole exome test is that it covers such a large amount of DNA. 1% of a person’s entire genome may not sound like much in the grand scheme of things, but it is a significant increase compare to older methods. Then there is the reduction time and money spent. A next-gen sequencing machine can sequence an individual’s whole genome in a few days, and some believe it will soon cost less than $1000 for users to get tested.
This whole exome sequence is a significant step forward for identifying the cause of illness and understanding an individual sequence. However, this focus on protein-producers only covers one part of the full sequence. There is no guarantee that the problems lie here. That is where whole-genome sequencing comes in. This method looks at the precise order of every single nucleotide to spot variations and anomalies.
DNA Sequencing Is Beneficial And Helpful But Research Is Not Done
There are still indeterminate factors and limitations with the whole genome and whole exome sequencing. This applies in particular when incidental or secondary findings come into play. At the moment, these recent advances in DNA testing are still providing great opportunities. Researchers are now able to look at the causes of diseases and the structure of the human genome in new ways. New research into genetic variations can provide answers to health care issues, or only bring up new questions to answer. There are always new problems and considerations in genetic research. This ongoing development and research mean that we will continue to find faster, more efficient ways of answering them.
DNA testing has entered the mainstream in recent years. The rise of at-home kits brought this genetic testing out of the science labs and into our living rooms. Accessible, consumer-friendly companies sell neatly-packaged products with fast results and fun analysis. Some get together with a family DNA test to learn about their heritage and trace distant relatives. Yet, things are beginning to change. There is a shift back to the detailed report of those scientific labs with the rise of DNA sequencing.
Consumers now have the chance to learn even more about themselves with detailed reports. Some will like the outcome, while others may be in for a surprise. So what exactly is DNA sequencing, how can it be of help and why is it still so controversial?
What is DNA Sequencing and how do these Tests Differ from At-Home DNA Kits?
When we talk about DNA testing and the potential for heritage analysis, labs focus in on specific DNA segments and molecules. There are only actually 4 chemical bases within a DNA double helix. There are Adenine, Thymine, Cytosine, and Guanine. These form distinct pairs of either Adenine and Thymine or Cytosine and Guanine. This sounds as though there would be limitations in these codes, but this isn’t the case when we have 3 billion base pairs in our own personal sequence. The pattern of this genome determines every trait that makes us who we are, from the color of our eyes to the genetic conditions we inherit.
A whole genome sequence looks at this complete line of code. This is about determining every detail of DNA rather than just key markers. This complexity explains why there are few fewer labs undertaking the process, and why the services cost so much. We have become used to the $99 family DNA test. This is much different.
Ongoing Developments in Genome Sequencing Means New Opportunities to Learn
The Human Genome Project was a massive undertaking when the initiative began. It seemed like an extreme notion to map out an entire human genome and make sense of all the genes. The project took sequences from a number of individuals to create a representation of the full human genome and its purpose. This still sounds incredible to many people outside of this scientific field. Yet, we have to remember that the HGP finished the project 15 years ago, with planning beginning as early as 1984.
Whole genome sequencing has evolved since then. It is easier than ever to sequence an individual’s genome in the appropriate lab. It took 13 years to complete the HGP, but now scientists can process over 100,000 billion bases in a year. This means plenty of consumers and patients with the opportunity to better understand their own genome. As technology and process increase, labs can become more efficient and the costs will decrease.
One area of development of particular interest is the use of nanopores. These small membranes read the bases of a DNA strand as it passes through the pore. The idea here is that this will speed up the process and allow for repeat studies on the same strand. This, in turn, means a better chance of reliable results for more patients. The complexity of this approach means that we are still a way off from seeing DNA sequencing in a local doctor’s office. But, lower costs and the accessible tech could pave the way for more labs across the country.
Whole genome sequencing provides a different service from the DNA test we know.
At the moment, DNA testing comes down to three key forms.
- Basic mitochondrial and chromosome family DNA test for heritage and family trees
- Detailed testing that can pick up on specific markers with DNA for healthcare and fitness testing
- Whole genome sequencing for a full picture of a user’s DNA
At-home kits for a family DNA test are a common gift. Many of these kits are affordable and easy to use, largely due to the vast number of companies supplying them. Leading brands compete to offer the nicest kit, the easiest process, and the fastest results. Families can swab their cheeks, mail off a sample and learn about their ancestry in a couple of weeks. This seemed revolutionary a couple of years ago. Now it seems quite basic compared to other options.
From here, many companies have since branched out into other areas of DNA testing. There is a market for more detailed, niche testing with a focus on different DNA markers. These tests find crucial information on key factors about our health and fitness. This includes information on metabolism, nutritional intolerances, and allergens. The results come back as a helpful chart with personalized information.
Whole genome sequencing is the next step up in many ways. Here the labs don’t hone in on a specific market, but instead, sequence the entire genome in full. This provides a complete genetic map with all the traits, issues and defects that may affect the individual. These tests are far more costly. Doctors can offer them as part of their service if desired. There are also labs offering the service much like those that sell DNA testing solutions. With time, this could become just as commercial.
These detailed DNA sequences can then aid users with their quests for better health and fitness.
The idea with these whole genome sequences is that doctors can supply them to patients with the aim of providing a genetic history. Patients can pay for the test, get the results and work with the doctor to make the right changes. A full genome sequence will highlight all the faulty genes and red flags. In some cases, the results may shed light on the reason for mystery symptoms and small ailments. Some people could receive new supplements or other precautionary aids.
The problem here is that these sequences will show everything, including factors that seem a lot worse than they are. A group of researchers from Brigham and Women’s Hospital, Baylor College of Medicine, and Harvard Medical School carried out a small study. In collaboration with a lab in San Diego, they sequenced the genomes of 50 subjects. 11 showed markers for rare genetic disorders – far more than expected. These individuals showed no symptoms of those diseases.
Source: Tedx Talks
Cancer Genomics is an Important Area of DNA Sequencing and Research
There are certain markers within the genome that highlight the risk of developing specific cancers. For example, it is possible to test for genetic risks of developing breast cancer. Women with a history of the illness in their family can undergo screening and find that they share that gene. This diagnosis allows them to take action to minimize their chances. Some choose to undergo mastectomies to remove the breast tissue and lower their risk.
Another important element of cancer genomics is the chance to analyze cancer within a patient for more effective treatment. This approach, known as precision medicine, allows for personalized cancer treatments. Care becomes tailored to the individual and their case. Targeted therapies such as these should allow for a higher success rate.
There are some clear benefits to this more in-depth DNA sequencing. Many consumers and healthcare professionals find this shift toward more detailed sequencing encouraging.
The advantages include the following:
- Possible information on key genetic traits with links to major diseases
- Detailed, personal healthcare information with actionable results
- Greater choice for consumers to learn more about themselves
The factors above highlight the potential advantages of greater access to genome sequencing. The intricate detail of these testing procedures means a great opportunity to learn about family health and unknown risks. People with a family history of a certain disease or cancer can learn a little more about their risk.
Those with symptoms of an undiagnosed condition may shed light on the problem. The detail of this uniquely personal data takes patients deeper unto their genetic makeup than ever before. The service may not be cheap, but the results could shape healthcare options for years to come. Proactive, helpful changes could arise from one or two interesting markers. Yet, there are some concerns about the future of DNA sequencing and its impact on healthcare.
There are some questions about the ethical ramifications of DNA sequencing. While some see the potential benefits, others worry about the stress that results may place on users. Problems with these tests include:
1) Concerns about causing fear in essentially healthy people
2) The desire to know all and cure all with physical health
3) The issue of penetrance in DNA sequencing.
Healthy individuals can opt for DNA sequencing and get a nasty surprise.
Going back to that study in Boston, there is a risk that results will seem worse than they really are. Around 20% of those studied showed DNA markers for serious genetic diseases. If that were indicative of the general population, that is a lot of potential patients with alarming results in their genome. Some may be calm and rational enough to gloss over them if they have had no major symptoms.
Still, cautious patients may wonder if every niggle or a persistent cough is the sign of something worse. An extra issue here is that idea of paying hundreds of dollars for a test. Some would argue that the cost is justifiable if it means better care and reduced costs in the future. Still, researchers question if this is likely.
DNA sequencing and screening could have deeper ethical issues.
There is always the question of how far we should go with new medical developments. DNA sequencing definitely raises some important ethical questions. Some people are therefore concerned about the future of healthcare with this increase in predictions. There is a desire to know all we can about our health and bodies, and to fix everything.
Medical science looks towards longevity and cheating death. Meanwhile, the world struggles to provide for an increasing, aged population. Developments in DNA sequencing of embryos raises questions over the acceptance of disability. This is especially true with conditions like Downs Syndrome. Iceland proudly claims to be close to eliminating Down’s Syndrome, but should they?
Source: Mollie Manier
Issues with penetrance don’t help the situation. Penetrance is an important word in the world of DNA testing that patients may not have heard. This basically means the probability of a genetic risk variant in the DNA turning into the condition. Many people can live with genes that signal a risk of disorders and know nothing of it – as with the study in Boston.
It is difficult to determine that probability and this could result in a few outcomes. Medics could get things right. They may correctly predict the risk, or lack of risk, and put patients on the right course of action. Or, they may get thing wrong. They could incorrectly predict the outcome. This may mean they either miss a chance for precautionary care or put patients through undue stress.
How can we make sure that the positive effects of DNA sequencing outweigh the negatives?
There are some clear upsides and downsides to this new approach to DNA sequencing. On the plus side, these detailed sequences offer up more information than ever before about who we are. These small details could unlock secrets about predispositions to illness and intolerance. This information then allows for further screening, precautions, and proactive steps.
The problem is that an overload of information can confuse and scare healthy consumers. The may have a higher risk of a major illness or cancer. Yet, that may be no more than 10%. Those with “bad” screening results may fear the worst with little understanding of the penetrance of the variant involved.
The issues raised here show why it is so important that DNA specialists develop their care packages. These detailed reports have great potential. But, this is only the case when married with comprehensive information and support from doctors and specialists.
Consumers of these tests have the right to know about any genetic risks. But, they also need to know when they are worrying about nothing. DNA sequencing has great potential in the right hands. With time, the prices will drop and these tests will help a lot of people.