DNA Testing

Grandparent DNA testing can determine a biological relationship between grandparents and grandchildren. Also, it is an indirect way of potentially proving paternity. For example, this could be useful if the potential father was deceased.

However, a DNA sample from the alleged father is not analysed as part of a Grandparent test. As a result, the DNA result will not identify the biological father of the grandchild in question.

Instead the Grandparent DNA test establishes the likelihood that participants are related as grandparent and grandchild, compared to the likelihood that they are unrelated. So the result of this test should only be used in combination with existing knowledge or circumstances of those involved.

How does Grandparent DNA Testing work?

We use the DNA samples taken from mouth swabs to generate a DNA profile for each test participant. Next, we compare the DNA profiles and determine the likelihood of a relationship. In this case, the likelihood that the participants are biologically related as grandparent and grandchild.

The test works on the fact that a child inherits half of his or her DNA profile from each of their parents. In other words, half the child’s DNA profile matches their mother and the other half matches the father.

Any child of the grandparents in the test will have a DNA molecule that is a 50% match to their mother’s (grandmother in test) and 50% match to their father’s DNA (grandfather in test). In turn, 50% of the genetic material inherited from each grandparent, will be passed on from their child. Therefore, DNA markers within the DNA profiles of potential grandparents will appear in the DNA profile of their biological grandchildren.

For example

The DNA passed onto a child from their father is inherited from the father’s parents (the paternal grandparents). Therefore, biological grandparents will have a certain amount of DNA in common with their biological grandchildren.

In fact, biological grandparents and their grandchildren, will share a significantly increased number of matches. This is when compared to the number of matches in the DNA of unrelated individuals.

This statistical analysis takes into consideration many different factors. These include the number of matches between the DNA profiles of each person. Also, how popular DNA markers are within a given population and ethnic group.

We use the values from the calculations to generate a percentage probability. This will show which relationship is most likely to exist between the individuals.


What Grandparent DNA Tests are available?

There are two types of Grandparent DNA Test:

Duo Grandparent Test

In this test, DNA samples from both the potential grandfather and grandmother are taken. This is in addition to the DNA sample of the potential grandchild.

The DNA profiles generated for both grandparents, include a complete set of the DNA markers inherited by any child born to said grandparents. A selection of those DNA markers will be passed on once again, becoming visible in the DNA profiles of their biological grandchildren. Having DNA from both potential grandparents, increases the number of relevant DNA markers for the scientists to analyse.

If both potential grandparents are available for testing, then the Duo Grandparent DNA Test should always be utilised. This test provides a greater chance of receiving conclusive test results when compared to the Single Grandparent DNA tests.

Single Grandparent Test

In this test, the DNA from a single grandparent (either the potential grandfather OR grandmother) is analysed and compared to the DNA of the child. This test should only be used if the second grandparent is unavailable.

If only one paternal grandparent is available for testing, it is very important to include a DNA sample from the biological mother of the child. This will increase the chance of receiving conclusive test results.


How long does it take to get your Grandparent DNA Test results back?

The analysis time needed in the lab for the Grandparent DNA Test is three to five working days*. We will always endeavour to get the results to you as quickly as possible. However, during busy periods in the lab, results may only be available on the fifth working day.

* Quoted lead-times are based on from when samples are booked onto the laboratory system. Also, quoted lead-times do not apply when issues arise from documents or samples provided that do not meet our quality guidelines.


How accurate is the Grandparent DNA Test?

These tests are very accurate. We achieve conclusive DNA results in over 99% of test cases*. But, as with any DNA test of this type, there is a small chance that the test will yield an inconclusive result.

Inconclusive results are not the same as negative results. An inconclusive result means that the analysis cannot provide an answer to the question asked. Inconclusive results occur in less than 1% of Grandparent DNA tests*. Causes of inconclusive results in DNA tests include:

  • The DNA markers that show matches between test participants are very common in the general population. As a result, the matches do not provide enough evidence to confirm if a biological relationship exists.
  • There is a lower level of DNA matches than expected. This is due to the chance nature of inheritance in families.
  • Where matches may have occurred, mutation has changed the DNA marker. As a result, this can cause mismatches at further locations within the DNA profile.

*Conclusive results are obtained in over 99% of Grandparent DNA tests when both potential grandparents are included in the test i.e. Duo grandparent DNA test.


Is the Grandparent DNA Test the right one for you?

The reasons for taking part in a Paternity, Sibling or Grandparent DNA test, are usually very similar. One is that there are potential biological relationships that exists between test participants. The second is that the evidence to support that biological relationship does not exist. In other words, the evidence is lacking or has been brought into question.

In the UK, the identity of a person’s biological mother is rarely questioned. So, we use DNA testing to gather evidence relating to the paternity (biological father) of one or more of the test participants.

To extract as much information from a DNA test, it is important to test the most direct relationship possible. For example, a test between parent and child, will always produce more conclusive results than a complex test. For instance, tests such as Sibling or Grandparent, test for relationships further removed from a direct genetic link. These tests can be very accurate. But they cannot replace those that directly analyse and compare the DNA of a potential biological parent.

For example, a male and female believe they may have the same biological father. They know that they have different biological mothers. If the alleged father is available to take part, then we would recommend a Paternity test.


What if the alleged father is not available?

The parents of the alleged father (the potential paternal grandparents) can take part in a test. As a result, the Duo Grandparent DNA test would be the next test recommended.

Also, what if a DNA sample is available from one or more of the participant’s biological mothers? In this case, then we would recommend a Sibling DNA test or a Single Grandparent DNA test.

We can also perform these test without the inclusion of a DNA sample from the mother(s). But a DNA sample provided by the mother would increase the information provided to the lab for analysis. We would recommend this as it will increase the chance of a more conclusive DNA test result.

Please note. Complex tests such as Sibling or Grandparent DNA tests, will not state the identity of alleged biological parents. In other words, we will not state who the alleged father is on the DNA test report.


How do I order a this DNA Test?

There are many options available to you, these include:

  • Order a free Grandparent Test kit from our online store*
  • Call to make an appointment at one of our DNA Clinics
  • Call to arrange for a sample collection technician to visit your location
  • You or your solicitor can contact us to organise a Legal DNA Test for court purposes

* Please note, you can only use self-collection kits for peace of mind purposes only.


Why choose DNA Clinics for this DNA Test?

  • DNA Clinics is a brand partner of Boots
  • Processing of all DNA tests is in a UK laboratory with UKAS accreditation
  • A standard turnaround of only 5 days for Grandparent Test results
  • Established in 2005, our team of experts will guide you through the science
  • Unrivalled convenience with a choice of over 50 DNA Clinics nationwide
  • Certification to 3 ISO standards. This includes Quality, Information Security and Environment standards
  • We are a registered company with the Information Commissioner’s Office


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