Everything You Should Know About DNA Test and Genetic Testing
A DNA test (or so-called genetic testing) is gaining popularity in the United States and around the world. It is estimated that almost 30 million Americans (over 10% of the population!) have been tested in the United States alone, and the number continues to grow. Do you want to learn more about these tests? We’re here to help you!
This blog is written by Team Genomelink, a group of experts in consumer genomics who know the market well. This post is genetic testing 101, in which we’ve tried to cover everything you should know about these tests!
What is a DNA test or genetic testing?
There are a few different names for these tests (e.g., genetic testing service, DNA test, genetic test, etc.). Let's use "DNA test" for now. DNA tests are services that analyze your DNA data and provide a number of genetic insights about you, such as your ancestry, family history, disease risk, macro/micro nutrition intake, physical body traits, and even personality and intelligence.
In the United States, services such as AncestryDNA, 23andMe and MyHeritage DNA are popular applications. According to The DNA Geek and publically available data, there are already more than 2.5 million people who have taken an ancestry test. AncestryDNA alone has reportedly sold over 1.5 million kits!
These tests usually analyze your autosomal DNA (chromosomes 1-22), sex chromosomes (X,Y) and mitochondrial DNA (mtDNA). The majority of these companies analyze single nucleotide polymorphisms, commonly known as SNPs (pronounced “snips”). SNPs are the most common type of genetic variation among human beings. There are several million DNA letters that illustrate the uniqueness of a person. By analyzing this data, these companies generate genetic information including genetic traits or ancestry analysis.
How to do a DNA test?
One of the main reasons these tests are becoming popular is that they are an easy and affordable way to analyze DNA data. You simply order a DNA test kit (also called testing kits) from the company's website, Amazon, or even off-the-shelf at Walgreens. Each package contains a saliva sample collection kit. All you have to do is spit your saliva as instructed and ship the sample back to the company. The instructions are simple and user-friendly. A return package with a prepaid address label is usually included in the DNA kit. After the company receives your DNA sample, it takes 2-8 weeks to get the results. (The turnaround time can vary considerably! You might enjoy this post by The DNA Geek!)
Which are the most popular genetic testing service companies?
Let me introduce two major testing companies - AncestryDNA and 23andMe.
AncestryDNA has the biggest user database and provides a comprehensive analysis of your ancestry. The company originally started out with a non-DNA test product, Ancestry.com, where a large number of people store and share their family history and family tree. Then, in the 2000s, the company began offering a DNA test and combined the experience of Ancestry.com and genetic testing. Now, the combined experience is very popular among people who are interested in DNA tests and exploring their ancestry. This has made AncestryDNA the number one company in this domain.
23andMe is another well-known consumer genomics company that focuses on ancestry and health. Founded by Anne Wojcicki in 2006, the company is a pioneer in consumer genomics. When it started out, 23andMe offered analysis of a number of genetic traits, including disease risks, but the FDA banned it and other testing companies from providing this information without FDA approval or the involvement of physicians. Therefore, now 23andMe is mainly an ancestry application. However, it has recently been getting approvals from the FDA to provide more information on disease risks, such as Type 2 Diabetes, Cancer, Celiac Disease, Late-Onset Alzheimer's Disease and Parkinson's Disease.
Which test is the best to learn about my ancestry and family history?
You want to know more about each application, right? Let's dive right in! There are a few companies that provide ancestry and family history analysis. Your ancestry report could give you information about your ethnicity estimates. For example, you may have a mixed ethnic background, such as Caucasian, Eastern or Western Asian, or even more specific regions, depending on the services you choose, such as Native American, Irish, Italian, French, Scandinavian, etc.
Ancestry stands out among the many genetic testing companies because of their specialty in genealogy. They focus on connecting families, giving you detailed information about your family’s past, including specific locations, and making records accessible to you.
Ancestry has 20 billion records and 20 million members. About 100 million family trees have been created on this website. You can build a family tree and search and browse historical documents, such as census and voter lists, birth, marriage, and death certificates, immigration and travel documents, military records, and card catalogs. You can track how your family moved over generations. You can match with relatives you may have around the world. Now, you can also get AncestryDNA Traits, where they describe around 18 physical traits that tell you more about yourself. The Compare feature allows you to compare these results with other family members you have connected with.
23andMe provides its users with two different packages. One is simply an Ancestry Service while the other is a Health + Ancestry Service. 23andMe uses cutting edge scientific research to continuously expand its database on health information. They were the first company to obtain FDA clearance for certain genetic traits and carrier status reports. They encourage users to participate in online research and give feedback via online surveys. This helps researchers link the data to various study topics.
MyHeritage has 103 million members, 9.6 billion records, 3.3 billion people in family trees, and 42 supported languages. You can build your own family tree and learn where your family originated from geographically. You can also search for specific people within the website’s research database. If you complete a saliva test, they analyze your specific DNA and give you an ethnicity breakdown from 42 different regions in the world.
MyHeritage has started “The Founders Project” to specifically test DNA from Founder Populations around the world. These are families that have lived in an area for generations. The diversified ethnic background database generated through this project helps others trace their origins to the founder populations and match with others in their family.
4. FamilyTree DNA
This service offers a Paternal Ancestry Test (for males only), Maternal Ancestry Test (for both males and females), and Family Ancestry Test (for both males and females). FamilyTreeDNA gives it’s users three different routes to explore their origins. Male users can specifically have a Paternal Line test done, which tracks and follows the migration paths of only the father’s line. Both male and female users can specifically have their Maternal Ancestry line tested, revealing the heritage in the mother’s family. Lastly, you can have a general Family Ancestry Test done, where your DNA is tested and broken down to show your origins. This will allow you to connect with ancient groups and other family members in the FamilyTreeDNA database.
The approach at LivingDNA focuses on genealogy. They use a cheek swab test to obtain your DNA information and reveal up to 15 generations of ancestral detail.
LivingDNA separates your motherline and fatherline (the y-chromosome), so you can look at the two sides of the family separately. You can find and connect with relatives from around the world as well as connect your family history with well-known historical events. LivingDNA breaks down your common ancestor information with detailed regional and sub-regional detail.
What are relative match services?
In addition to ancestry analysis, some companies offer a "relative match" service which allows you to find people who share a certain amount of DNA data with you, meaning they could potentially be a family member you have not yet met! This is attractive to people who are interested in genealogy and keen to build their own family tree. The service has been recently becoming more popular among DNA test users who want a new experience beyond simple ethnicity analysis.
For example, AncestryDNA started offering a relative match service as well. It shows you a list of people who have consented to be included in the relative match results. You can then contact potential new family members or distant relatives through the site.
Also, GEDmatch provides DNA and genealogical analysis tools for both amateur and professional researchers and genealogists. The chromosome browser (which matches specific bits of genomes between relatives) is amongst their most popular tools. Millions of users are registered on its relative match database with full contact information, including email address, first name, and last name.
What health and wellness DNA test services are available?
Health and medical services are a valuable category in DNA applications. A good example is the BRCA gene, which is one of the most medically validated genes that influence the risk of breast cancer. However, before taking a DNA analysis test for breast cancer susceptibility, you should be aware that there is still a big debate about how these tests should be conducted and by whom. At this point, testing of specific genes is heavily regulated and can be ordered only through physicians. There are some companies, such as Color Genomics, that offer a direct-to-consumer DNA test in medical applications (they involve physicians in the ordering process), where you can purchase a $99-$199 DNA kit to test your hereditary cancer risks, including BRCA.
Compared to medical applications, wellness-related services are more common. There are several companies that provide nutrition and fitness advice based on your gene profile, including Pathway Genomics, VitaGene, GenoPalate, or Athletigen, etc. Some of them accept DNA data upload as well (learn more about "DNA upload"). Recently, large corporations like NutriSystem, GNC, Jenny Craig and Nestle have started offering DNA tests as well. Even though Nutrigenomics (Nutrition + Genomics) is still in the infancy phase and there is an ongoing debate about its scientific validity, there is a positive push from the science community. For example, NutriSystem cites a position paper published by the Society of Nutrigenetics in 2016, saying "the value of nutrigenetic information warrants the inclusion of this information to inform personalized diet recommendations. Furthermore, this position paper provides evidence that genetically-informed dietary advice is better understood and more likely to be adhered to than general dietary guidelines."
Personality or intelligence DNA tests: Are they true?
In addition to medical and wellness applications, personality and intelligence tests are also interesting for many people.
In the history of genetics research, one thing that has been well studied is "twin research.” This is more of a social science approach where researchers follow identical twins who grew up in different environments. The researchers analyze characteristics in the twins to identify the influence of genetics. This type of research has shown a strong correlation between genes and characteristics such as personality and intelligence.
However, research with DNA tests and the bioinformatics approach is still in an early phase and the results tend to vary depending on the traits studied. If this interests you, there are some engaging services and websites where you can analyze your personality and intelligence traits based on this new science!
Does my ethnicity matter to get accurate results?
Yes. Much of genomics research is still focused on Caucasian (European) ethnicity. If you have a different ethnicity, such as Hispanic, African Americans, or Asian, you should use a service that has compatibility for your specific ethnicity.
Specific genetic testings are offered for a particular ethnic background as well. For example, the BRCA test by 23andMe is specifically designed for the Ashkenazi Jewish population because the "test detects three selected variants in the BRCA1 and BRCA2 genes... that are among the most studied and best understood. These three variants are most common in people of Ashkenazi Jewish descent."
What is "DNA upload" to third-party companies?
This is one of the most interesting things about DNA tests! Usually, it is possible for you to download your raw DNA data from the testing service website and use this data for other services. Raw data means your original text file of genetic data, which looks like this. After you have your DNA results, all you have to do is go to the particular web page (you can find the page by simply googling "DNA upload [DNA test name]") and the entire process takes just a few minutes.
Once you have the data, you can go to a website like Genomelink (yes, that’s us!) where you will find 125+ genetic traits, including Food & Nutrition, Personality, Intelligence, Fitness, and Physical Traits. You can try it for free with access to 25 traits!
Also, here’s a list of other websites where you can use your raw DNA data to maximize your DNA experience!
Are there any dog DNA tests?
Yes, companies like Embark, Wisdom Panel and DNA My Dog offer these services!