Y-DNA STR Marker Test

To supplement the results a relationship test, such as a sibling test, grandparentage test, uncle test, or cousin test.


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Common uses for Y-DNA STR Marker Testing:

Y-DNA STR marker testing is a specialized DNA test focusing on the male Y chromosome. It’s particularly useful in tracing paternal lineage and clarifying family connections. Here’s how it’s commonly used:

Tracing Paternal Lineage Across Generations

This test can determine if two men share the same paternal ancestry, even if they’re not closely related. Since Y-DNA and surnames are both passed down from father to son, men from the same paternal line can use this test to see if they share a common paternal ancestor.

To supplement the results a relationship test, such as a sibling test, grandparentage test, uncle test, or cousin test

While DNA parentage tests such as the paternity and maternity tests give definitive results, tests for other relationships like siblings, grandparents, uncles, or cousins might not always be clear-cut. Y-DNA STR testing can be used alongside these tests to provide additional clarity. This is particularly useful when the parents are not available for testing. In such cases, comparing the Y-DNA profiles of males involved can confirm or rule out a direct male line relationship. For example, if two males do not share the same Y-DNA STR profile, it’s conclusive that they are not related through their direct male lineage.

Here are some examples of situations where a Y-DNA STR marker test may assist in supplementing a relationship test:

Grandfather and Grandson

If a test to check if someone is the true grandchild of a man isn’t clear, Y-DNA STR testing can help. This test looks at the Y-DNA, which only males have and pass from father to son. If the grandfather and grandson’s Y-DNA don’t match, it means they are not biologically related as grandfather and grandson.


If a DNA Sibling Test is inconclusive, Y-DNA STR testing can help determine if brothers share the same father.

Paternal Cousins

For male cousins unsure if their fathers are brothers, Y-DNA STR testing can be used when a regular DNA Cousin Test doesn’t give a clear answer. If the cousins’ Y-DNA doesn’t match, it means their fathers are not biological brothers.

Uncle and Nephew

When an uncle and nephew test is inconclusive, this test can help. If the uncle and the nephew have different Y-DNA, it shows that the uncle is not the biological brother of the nephew’s father.


No, all males who have descended from the same paternal line will have the same Y-DNA STR marker profile. For example, it cannot distinguish a father from brother or a grandfather because all males from the same paternal line will have the same Y-DNA profile. If two males do not have the same Y-DNA proflle, then it would conclusively prove that they did not descend from the same paternal lineage.

No, females do not have Y-DNA so females cannot take the Y-DNA test.

You can choose to receive your results by mail, email or both. Email is the fastest way to get your results back because the email reports are sent out the same day that the test is completed.

The more Y-DNA STR markers you test, the more stringent your comparison with another individual. For example, a perfect 101/101 marker match with another individual is a much stronger match than a 20/20 match. It is ok to test 20 markers first to see if there is a match. If you are already not matching the other individual at 20 markers, then there is no need to test more markers. However, if you get a perfect match with another indivdiual or a very close match (such as 19/20), then you can get further confirmation by testing more Y-DNA STR markers.

The report will only give you your Y-DNA STR profile. The report will not provide you with your Y-DNA haplogroup and it will not make any ancestral interpretations. If you wish to trace your ancestry using DNA, please see the Paternal Ancestry Test.

Yes, your results are 100% confidential. No one will be able to access your account or your results unless you give them your confidential account login. You can change the password to your account at any time. Please remember to safeguard your login information and do not share it with anyone.

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