What Are Genetic Ancestry Tests?: MedlinePlus Genetics

Some DNA tests have been approved to share information about a person’s genetic health risk for developing 10 medical conditions, including Parkinson’s disease, celiac disease, late-onset Alzheimer’s, along with various blood and tissue clotting disorders. Genetic ancestry testing, or genetic genealogy, is a way for people interested in family history to go beyond what they can learn from family members or historical documentation. Examining DNA variations can provide clues about where a person’s ancestors may have come from and about relationships between families. Certain patterns of genetic variation are often shared between people from a particular background. The more closely related two individuals, families or populations are, the more patterns of variation they usually share.

Deviations from the expected number of chromosomes can lead to a diagnosis of certain genetic disorders such as trisomy 21 or monosomy X. In the 1970s, a method was developed for coloring specific regions of chromosomes called chromosome bands, which allowed a more detailed analysis of the chromosomal structure and the diagnosis of genetic disorders with large structural rearrangements. According to the National Institutes of Health, there are tests available for more than 2,000 genetic conditions, and one study estimated that there were more than 75,000 genetic tests on the market as of 2017. Still, the results are not diagnostic, although the test result must be approved by one of the company’s doctors and the service does not have FDA approval. For now, 23andMe maintains the lead when it comes to introductory DNA testing for health risks and genetic screening. But ancestryDNA’s service is particularly well suited to using introductory DNA analysis in deep historical research to build a family tree.

The counselor can tell you about the pros and cons of the test, what the results, and the best testing options available based on your family history can mean. But if you just want an ethnic breakdown without the potential to discover unknown family ties, services like 23andMe and FamilyTreeDNA don’t reveal DNA Test any of your information to other customers until you sign up for their family matching services. In October 2019, the company launched AncestryHealth, a health-focused service that is immediately available to existing AncestryDNA customers for a one-time upgrade fee and for new customers for purchase.

For example, genetic testing can provide a diagnosis of a genetic condition such as Fragile X or information about your risk of developing cancer. Genetic testing is done with a blood or saliva sample and the results are usually ready within a few weeks. Because we share DNA with our family members, your relatives may have the same change if it turns out that you have a genetic change. Genetic counseling before and after genetic testing can help ensure that you are the right person in your family to be genetically tested, that you are getting the right genetic test, and that you understand your results. The first forms of genetic testing that began in the 1950s involved counting the number of chromosomes per cell.

But it can determine the likelihood that your baby will be born with certain conditions that we know how to look for. If your baby is at increased risk for a genetic condition due to the family’s genetic background, your healthcare provider may recommend prenatal testing. 23andMe segments its analysis into three main categories: health, ancestry and traits.

FamilyTreeDNA’s more detailed tests can cost you more than three times as much as you would spend on the company’s basic autosomal test or that of its closest rivals. But you get what you pay for, and if you’re dedicated to digging up family history and familiar with terms like SNP (pronounced “snips”) and centiMorgans, you’ll feel right at home in the community of clients who focus on the company’s genealogy. The company claims a much smaller DNA database than AncestryDNA and 23andMe, but still offers a reasonable chance of connecting with family members. FamilyTreeDNA’s ethnicity estimates for our test panel were broadly similar to those of AncestryDNA and 23andMe.

There’s always the possibility of errors when running these types of tests, so talk to your provider about this before doing so. Julie Granka, AncestryDNA’s custom genomics manager at the time of our interview, explained to us that the company is starting to identify customer groups in its database with similar ancestral DNA. Through the process of analyzing historical data, such as family trees provided by the client and other paper trace documentation relevant to this collection of individuals, the company can reconstruct the geographic movements of that community over time.

You can also choose to learn more about certain genetic health risks and whether you are a carrier of certain hereditary conditions. I found 23andMe’s website and mobile app to be very easy to navigate and packed with interesting and understandable information about my ancestry and health, as well as the science of genetics and genealogy. The main panel provides intuitive links to explore your ancestry, learn about the genetic risks of health problems, build a family tree, and connect with family members.

When a healthy person without symptoms has a documented family history of a disease, such as diabetes, genetic testing can look at specific markers in their genes that are linked to that disease, Feero said. The picture is confusing for the average consumer, and it can be difficult to know which genetic tests should be taken seriously. Large ancestry testing companies, such as AncestryDNA and 23andMe, may be characterized as “recreational,” but they employ teams of scientists and rely on solid data to understand the genetic relationship and track ancestral inheritance patterns. Direct-to-consumer genetic testing (also called home genetic testing) is a type of genetic test that is directly accessible to the consumer without having to go through a healthcare provider.