Questions About DNA Test Results
We genealogists joke that we prefer dead people, but DNA testing involves working with and matching living relatives to determine how we’re related. The primary goal of genetic matches is to determine who are common ancestors are. We can take advantage of genetic genealogy’s great tools for breaking through brick walls, but doing so effectively also requires some study to understand your DNA test results.
Here are some common questions answered in our Genetic Genealogy 201 course.
How can I get my relatives to test?
If your relatives are worried about keeping their results private, inform them about GINA – the Genetic Information Nondiscrimination Act of 2008. This federal statute prohibits the use of genetic information from your DNA test results in health insurance and employment. While it doesn’t cover everything, it may alleviate your relatives’ concerns. Learn more about GINA here.
How Can My Sibling’s DNA Test Results Show Different Ethnicity?
No two people are exactly alike, not even full siblings. So unless you’re an identical twin, you inherit about 50% of your DNA from each parent but not the same exact 50%. Different markers will show up in each sibling based on what DNA gets passed on from your grandparents to your parents to you. You may have inherited your nose from your father, but your eyes from your maternal grandmother. The same principle applies to your ethnicity results.
What is Triangulation?
Triangulation is a technique used with autosomal DNA to compare matching segments of at least three people to determine which ancestor donated a particular segment to the group. This can help pinpoint the most recent common ancestor (MRCA) you share with your matches. You can read more about triangulation in this article as well.
Why do I need third-party tools?
Third-party websites, such as GEDmatch or DNAGedcom, can offer a wider array of tools to work with your matches. Because GEDmatch allows you to upload raw test results from AncestryDNA, FamilyTreeDNA, and 23andMe, you can match people who took tests at any of those companies. While the tools for each testing company are useful, third-party tools can offer extra resources and larger pools to work with.