There is plenty to consider when choosing the right DNA test for your situation. We provide guidance below, but our Clinical Advisors will also guide you through the options available when you book your test.

Always test the most direct relationship possible

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.

In addition, please read our article regarding establishing paternity for potential fathers who are related.

What if an alleged father is not available for testing?

If the parents of the alleged father (the potential paternal grandparents) are available, they can take part in a test. In this case, the Duo grandparent DNA test would be the next test recommended.

However, because a DNA sample from the alleged father is not analysed as part of a grandparent test. As a result, the DNA result will not directly 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.

Also, what if a DNA sample is available from the potential father’s biological mother? In this case, then we would recommend a sibling DNA test if siblings were available, or a single grandparent DNA test.

We can also perform DNA tests without the inclusion of a DNA sample from biological mothers. But a DNA sample provided by the mother would increase the information given to the laboratory for analysis. We would always recommend this as it will increase the chance of a more conclusive DNA test result.

As mentioned, 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.