A Guide to DNA Tests
By Dr. Brandon Colby MD, an expert in genetic testing and personalized medicine.
DNA tests have increased in popularity over the last several years. The first major breakthrough most people know about is when researchers revealed the effectiveness of genetic testing for breast cancer (BRCA1 and BRCA2 gene mutations).
The next time DNA testing made a huge impact on society was when testing companies 23andMe, Ancestry.com and MyHeritage started to offer DNA test kits to collect DNA data to analyze for information on ethnicity, health, and possible relatives.
DNA testing is much more than just identifying breast cancer and ancestry. Learning about them in this guide can help you take advantage of them fully to improve your health, wellness, and even possibly help you live longer.
What Is a DNA Test
DNA tests, also known as genetic tests, identify changes in the DNA sequence or chromosome structure. Medically, a DNA test can diagnose or rule out genetic disorders and predict the risks of certain conditions. It's similar to a health test in this way.
DNA tests can also determine relationships between mother or father and child or ancestors. Paternity DNA testing is highly popular in instances where the father of a baby is questionable. DNA testing sites such as 23andMe and MyHeritage offer ancestry DNA tests to identify possible relatives living or dead. Many parents choose to have genetic testing to find out if they have carrier status for certain genetic disorders that may be passed on to their children. DNA tests can reveal a lot of very important and insightful information.
Most commercial DNA tests involve either spitting into a test tube or a swab of the cheek. The DNA sample is sent to a lab to extract the data the DNA holds.
The DNA results are then analyzed to provide genetic information for the user. For instance, if someone is interested in knowing about additional family members, the analysis identifies DNA matches between people.
Learn More: What Is a DNA Test
How Does DNA Testing Work
DNA testing or genetic testing is quite simple. A person sends their DNA sample to a lab where a technician will look at changes in the DNA, proteins, or chromosomes. The technicians note genetic data and upload it to a DNA database.
The person who provided the sample will receive notice the DNA test results are ready, and then, the person can use the data in any way he/she desires.
Many labs will gather DNA data and analyze it according to what the DNA test was meant to provide. For instance, if someone submits a paternity test, the DNA data is then compared to the second DNA sample submitted. In cases where people want to know the genetic health conditions they are at risk for, the technician may analyze the DNA data to identify genetic markers for specific inherited diseases.
Learn More: How Does DNA Testing Work
How Accurate Are DNA Tests
DNA tests are highly accurate, but the information provided by some DNA testing companies isn't as thorough as it could be for people. For instance, some home DNA tests only provide information about one or two genes. But each person has more than 20,000 genes!
Only having DNA data for a few genes won't provide the raw data necessary to reveal a predisposition to many genetic health conditions. Just because the DNA testing kit doesn't provide a lot of information doesn't mean it's not accurate. Buyers should simply be aware that not all DNA tests are created equal and much more comprehensive ones are available to provide better DNA matching and analysis.
Learn More: How Accurate Are DNA Tests
What the Food and Drug Administration (FDA) Believes
The FDA hasn't been quick to embrace DNA testing but as more research has surfaced, the organization has started to acknowledge it more as can be seen in these press releases.
- FDA Announces Collaborative Review of Scientific Evidence to Support Associations Between Genetic Information and Specific Medications
- FDA takes new action to advance the development of reliable and beneficial genetic tests that can improve patient care
- FDA allows marketing of first direct-to-consumer tests that provide genetic risk information for certain conditions
How to Read a DNA Test Report
Most people review DNA tests with a genetic counselor. Genetic counseling helps people process the information in a DNA test accurately so there isn't any emotional upheaval over misperceptions. Consulting with a genetic counselor is recommended especially if there is a concern over a health risk.
Some DNA testing services, like Sequencing.com, offer genetic counseling to make the process of understanding the results easier. This genetic counseling is available online to make it quick and easy to understand analysis reports providing by the DNA company.
There are some DNA testing companies that provide an explanation of the results in their analysis reports, such as Sequencing.com. In a Sequencing.com analysis report, individuals can see their DNA data and how it relates to the conditions or traits analyzed. There's also an explanation of the results written in a simple and easily understood manner.
DNA test analysis reports can also be used by a health care professional. A doctor can interpret the results and use the information to prescribe medications or help with diagnosis depending on whether the person has a genetic disposition to a certain health condition.
What Does a DNA Report Look Like
The way a DNA report looks varies depending on the DNA company. But remember, a DNA test report is different from a DNA analysis report. A DNA test report will contain raw data to be analyzed so it will simply be strings of letters and numbers. Those letters and numbers are analyzed to deliver the information that people can use.
The following are some DNA reports to give you an idea of the difference between DNA test reports and DNA analysis reports.
DNA Test - Raw Data
This raw data is what a DNA test provides so that it can be analyzed to provide useful information.
DNA Test Analysis Report
Below you will see the information that is derived from DNA raw data.
It's possible to browse many other DNA test analysis reports in Sequencing.com's App Market.
How Long Does DNA Last
A person's genetic makeup never changes. This means DNA data never changes. When someone gets a DNA test, they can use the results forever to help their health and well-being. For instance, if someone uses the Medication and Drug Response analysis app on Sequencing.com, the results from the analysis can be used for the rest of their life.
The Medication and Drug Response analysis app identifies the best medications for a person for certain medical conditions. It also provides dosing information, likely medication side effects, and the possibility of addiction. Whenever someone has a health concern, he/she can offer the analysis report for reference when determining the best drug treatment.
Free DNA Tests
Free DNA tests that give you the raw data do not exist. Some websites will mention free DNA tests, but there's usually a catch to get someone to pay for it.
For instance, a free DNA test may be offered if someone pays for a monthly membership to a site or another offer will be given with the cost of the DNA test added. It's up to the buyer to decide if the value of the free DNA test is worth the money.
The only way to get a free DNA test is to become a participant in a research study. The researchers will ask you to provide a DNA sample and many of them will give you a full genetic analysis.
One research project that performs free DNA tests is the All of Us Research Project. This project is based in the United States and is federally funded. Researchers want to analyze the participant's genetics along with their diets and lifestyles. The goal is to understand genetics much more fully for use in precision medicine.
If you're interested in this project, sign up at Join All of Us.
The University of Michigan has an ongoing study as well. It is only open to United States residents and they use Facebook for applications. After submitting the application, the researchers mail an autosomal DNA test to you. All you have to do is spit in a tube and send it to their lab.
This project allows participants to use their chromosome browser. This browser allows users to uncover where autosomal DNA originated. The results provide health + ancestry, including:
- Health-related SNPs
- Genetic genealogy report
- Health and disease
For those who want family history information, try the International Society of Genetic Genealogy (ISOGG). They have a page that has a list of last names. Search for your last name. The projects on this site are funded privately and help people complete their family trees. Some of the projects only focus on analyzing the paternal line or Y-chromosome haplogroup with a y-DNA test. while others the maternal one - the mitochondrial DNA (mtDNA). Checking the site regularly for opportunities may be necessary to end up with a free DNA test.
It is important to know that while these free DNA tests provide information, they do not give participants their data. Participants only receive the information the research study has so there is no way to further analyze your DNA data if you're interested in learning something else about your genome.
While free DNA tests that provide raw data to you may not be available, free DNA analysis is available. With raw data, it's possible to learn about your ancestry, health, personality, inherited diseases, and much more. Browse free DNA test analysis apps here.
Can a DNA Test Be Wrong
A DNA test can be wrong but it's usually because of human error. Erroneous DNA test results occur because:
- The DNA sample was collected incorrectly.
- An insufficient amount of DNA was collected.
- Someone else's DNA sample was submitted in the case of paternity tests
Some people believe a DNA test is inaccurate when seeing their analysis results because they don't align with their beliefs. For example, they may believe they are of a certain ethnicity because their family told them they are, but then the ethnicity estimates come back with different findings. Most of the time, people find out their analysis results were correct and the information passed down from generation to generation was false.
An example of the above is someone believes they are of Native American descent but then receive their DNA analysis report showing they do not have any DNA matches for that ethnicity. While the person may immediately blame the DNA test, it's likely the word of mouth that is incorrect.
For health DNA analysis reports, some people may question why it identifies a heart condition when they are very healthy. Diet and lifestyle can change the projection of health. While genes may indicate a predisposition to a heart condition, it's possible to prevent it with a healthy diet and exercise.
A DNA test simply provides information to be used for analysis. The information may be affected by human error, but will most likely return inconclusive results if that is the case. Analysis shares what the test information means and that is not wrong. It uncovers generational information and predicts the future - it does not dictate the future, though.
The Best DNA Tests
Many people head to Amazon when looking to buy something, but in the case of DNA tests, it's best to stick with a company that is heavily vested in genomics. DNA testing companies such as Sequencing.com, Living DNA, 23andMe, MyHeritage, Ancestry.com, FamilyTreeDNA, and others work hard to ensure that their users receive the DNA data and analysis they sign up for when joining their site.
Many of the above sites are limited in the genetic information they provide because they focus on just one or two areas, such as health + ancestry. A site like Sequencing.com focuses more on sharing information from DNA data. While the DNA company offers DNA test kits (Ultimate DNA Test and Whole Genome Sequencing), the focus is on offering apps that analyze DNA data to uncover as much genetic information as possible. With analysis apps, people can learn about predispositions to rare diseases, common health conditions, what exercise is best for their body, what foods are best for their body, and even the right medications and dosing for certain medical conditions.
DNA data can be retrieved from DNA testing companies and uploaded free to Sequencing.com. So, people do not have to buy a DNA test from the site to take advantage of the analyses offered.
However, for those who have not chosen a DNA test yet, Sequencing.com offers two great options. The Ultimate DNA Test which is comparable to ones from other DNA testing companies or the best DNA test available online (clinical-grade) - Whole Genome Sequencing DNA test.
DNA tests are useful for people in multiple ways. As more people use DNA testing or genetic testing and spread the word about how much it has helped them, the more people will take them and so on and so forth. Cost is sometimes an obstacle for people, but perception is everything. DNA testing is an investment in your health and wellbeing as well as future generations.
About The Author
Dr. Brandon Colby MD is a US physician specializing in the personalized prevention of disease through the use of genomic technologies. He's an expert in genetic testing, genetic analysis, and precision medicine. Dr. Colby is also the Founder of Sequencing.com and the author of Outsmart Your Genes.
Dr. Colby holds an MD from the Mount Sinai School of Medicine, an MBA from Stanford University's Graduate School of Business, and a degree in Genetics with Honors from the University of Michigan. He is an Affiliate Specialist of the American College of Medical Genetics and Genomics (ACMG), an Associate of the American College of Preventive Medicine (ACPM), and a member of the National Society of Genetic Counselors (NSGC).
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