Grandparent DNA Test

To confirm a biological relationship when a possible father is unavailable.

Want to confirm a biological relationship with a grandchild?

When a possible father isn’t available for paternity testing, one or more of his parents can participate instead. The child’s mother is encouraged to add her DNA to the test as well since it helps to expedite analysis and can strengthen results. Whether you just want to know for your own peace of mind or obtain a report for legal reasons, we provide the accurate answers you need to know. The report is posted to your secure online account 5 business days after all grandparent test samples have been received at the lab.

The DDC Promise

Results in 5 Business Days

Once all samples arrive at the lab.

PhD-Reviewed Results

Our in-house team ensures accuracy.

Team Support

We keep you informed every step of the way.

Still not sure what test is right for you? Contact our experts today for a free consultation.

When set up as a legal case, results from a grandparent DNA test can be used for court.

Reasons to get a Grandparent DNA Test
The most common reason for grandparents to take a DNA test is to confirm the truth about a biological relationship, but there are more possible reasons to take a grandparent paternity test, like:

  • Medical history
  • Social Security benefits
  • Inheritance claims
  • Insurance claims

Results are completely confidential, and your private genetic information is never shared with or sold to outside parties.See our privacy policy here.

Testing Options for Grandparent DNA Testing

There are two main options for doing a grandparent DNA test: legal or for personal knowledge.

Legal: Legal test results can be submitted to court as legal proof of a biological relationship. DDC coordinates DNA-sample collection at an approved location near you. The professional collector then compiles all identification, completes paperwork for the test, and sends the package to DDC for testing.

Personal Knowledge: If you need the grandparent DNA test results solely for peace of mind and not for legal reasons, you have the option to collect your DNA at home and send it to DDC for testing. Keep in mind results are not court admissible.

TIP: If you think you may need results for court in the future, we suggest you do a legal test first, so you only have to test once.

To order a Grandparent DNA Test, call

More about this Test

Q: How accurate is a grandparent DNA test compared to a paternity test?
A: A grandparent DNA test is as accurate as a paternity test, although the conclusiveness of results can vary more. For example, the probability of a relationship between a father and child is almost always 99.9% or higher, but for a single-grandparent test (where only one paternal grandparent is tested instead of both paternal grandparents), the probability of relationship might be 92%— which is nevertheless still considered a conclusive result. To strengthen the conclusiveness of test results, we recommend that both paternal grandparents test (if possible) and that the child’s mother participate in testing, as well. When both paternal grandparents and the mother participate in testing, probability of paternity is nearly always 99.9% or higher.
Q: Can we test using just one grandparent?
A: You can do this grandparent DNA test using samples from just one paternal grandparent and the child; however, the chances of obtaining conclusive results are reduced. If possible, we always recommend including the mother’s DNA in both single-grandparent and grandparentage (both paternal grandparents) DNA tests. Ideally, both paternal grandparents would test, along with the child and the mother.
Q: Can a grandparent DNA test be done without the mother?
A: Yes, a grandparent test can be done without the mother, although we highly recommend that the mother be included as well. Her participation helps the analysts to more clearly determine which of the child’s DNA comes from the father’s side and which comes from the mother and it can also help to strengthen the probability of relationship percentage.
Q: Can a grandparent DNA test be used for legal reasons?
A: Yes; a grandparent DNA test can be used for legal reasons as long as a chain-of-custody procedure has been set up and followed:

  • The test is ordered directly from DDC
  • DDC schedules a DNA-collection appointment for test participants at a convenient facility near them
  • Test participants provide proof of identity at the appointment and DNA-collection is witnessed
  • The facility signs paperwork and returns samples to the lab for testing

Results from a legal grandparent test are court-admissible and can be used for legal reasons such as Social Security, inheritance rights, custody, and more. Results for an at-home grandparent DNA test cannot be used legally.

Q: Does the mother need to consent to a grandparent DNA test?
A: Whether the test is an at-home or a legal one, the responsibility is on the tested parties to ensure all parties and/or legal guardians agree to testing. See Section 4 (n) of DDC Terms and Conditions.
Q: How do I understand results for a grandparent DNA test?
A: Understanding results for a grandparent DNA test is a little tricky, since there can never be a straight “yes or no” answer in relationship testing. Calculations for relationships such as grandparent, avuncular (aunt/uncle), and siblings all involve statistics, and a probability of relationship is given as a percentage in the report:

  • 90% or higher: the relationship is supported by DNA testing
  • 9% – 89%: inconclusive result, and additional parties need to be tested
  • Below 9%: the relationship is not supported by DNA testing

If a probability of relationship (PRI) of 92% is given for a grandparent test, the result could be understood as: “There is a 92% probability that the persons tested share a grandparent/grandchild relationship.”

Still have questions about the Grandparent DNA Test? Please contact us.