Y Chromosome Test (Y-STR)

The Y chromosome is found solely in males and is inherited from the father. Testing this chromosome by means of a Y chromosome test, sometimes called a Y-STR test, can thus be useful in establishing whether two males have the same paternal line.

How the test works

In cases where an alleged father is not available for testing through a paternity test, we would likely recommend doing this type of test between male siblings in order to establish if they share the same paternal line and are thus, brothers.

the test may also be done when two first cousins wish to determine in a scientifically reliable way whether their fathers were in fact brothers, or to check if their grandfather is common to both. In such cases this may be determined by doing a Y-STR test.

The Y chromosome test can be used to confirm paternal relationship whenever a direct male line can be drawn between the participants.

It is important to understand that this type of test may not always be able to determine the exact relationship between males, for example whether an individual is your father or uncle or grandfather. The result therefore needs to be interpreted within the context of the case.

The Y chromosome has a very low rate of mutation and therefore, it provides a reliable means of testing for biological relationships between males. The test will show the Y-STR profile for each male tested.

Y chromosome testing is priced at  £199.00 for two males to be tested with results ready in only 5-7 working days. Proceed to Order Here.

Return to our relationship DNA testing to keep reading more on the tests between relatives that we offer.


Order your X or Y Chromosome Test from homeDNAdirect UK today!


X Chromosome Testing

This X Chromosome test is useful in cases where two females wish to establish whether they share the same father. The test is straightforward when the two sisters have different mothers; thus, what they seek to determine is whether they are half siblings or no siblings at all. In this situation, we do not require testing the samples of the mothers. The test will map the X-chromosome pattern of the two alleged siblings and if there is a match then this will confirm they share the same father.

Results of the X chromosome test

In cases where the alleged sisters share the same mother, then we will require the mother’s DNA sample to conclude the test. A female inherits an X chromosome from the father and an X chromosome from the mother. By identifying the mother’s DNA profiles, we can exclude her share of X chromosome from the test.

There may be cases in which half sisters are not able to provide the mother’s DNA sample. In this case, we cannot conclude the X chromosome test. The only available option is for the alleged sisters to do a siblings STR test which will determine whether the biological relationship between them is strong enough to indicate they are full sisters.

Paternal grandmother and granddaughter

The X chromosome test can be used between paternal grandmother and granddaughter as they must share one X chromosome. This shared X chromosome is the one that the grandmother passed to her son and he, in turn, passed to his daughter. We only need DNA samples of the paternal grandmother and granddaughter for this test. We require no other samples in this particular case.

The X chromosome test is offered starting from £329.00 and this covers testing for two sisters. Your results will be sent to you by email in 15working days. You can order your test now or read more on our DNA relationship test page.


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