X Chromosome Test

Starting from only £329 with results in 15 working days

The X chromosome test will enable two or more females to establish whether they share the same biological father. This DNA test, often used instead of a paternity test when the alleged father is not available, can only be carried out between females but can give very accurate results*. An X chromosome DNA test can also be used instead of a sibling DNA test when the alleged siblings have different mothers and want to know if they have the same father.

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Sending Your DNA Samples Takes Just 5 Minutes

We want our clients to complete their test quickly and with the least hassle possible. To help you collect your DNA samples easily, we have created a home sample collection kit with our clients’ needs in mind.

Our standard method of sample collection is using mouth swabs which are included in your kit. Each test participant can collect their own samples by rubbing the mouth swabs inside the mouth, under the tongue and against the cheek. This simple procedure collects cheek cells on the cotton tipped swabs. The cheek cells are what we then use for our laboratory to extract DNA for analysis.

Besides the swabs, you will have a sheet with precautions to take before your sample collection as well the step-by-step instructions you need to follow.

You kit will also contain sample submission forms (documents which should be completed with personal details, signatures of consent and their email address for the results) and a self-addressed envelope. Once you have collected your samples and filled out the sample submission form, you just need to put these all into the bigger self-addressed envelope and send it back to us.

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Getting Your X Chromosome Test

Our X chromosome test is available starting at only £329 with results in 15 working days.

Note that our result turnaround time starts from when we receive your samples. As soon as samples are received, we will send out an email with your result due date.

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Including the Mother in an X Chromosome Test

When we perform an X chromosome test, we test a 10 genetic marker profile for each test participant to look for a match between profiles from different participants.

All females inherit an X chromosome from their father and an X chromosome from their mother. When the laboratory confirms a match between X chromosome profiles of the tested parties, we need to distinguish the paternal inherited and maternally inherited X chromosome.

Therefore, please keep the following in mind:

If the females being tested have different mothers the test is straightforward because the tested females can only share one X chromosome – the X chromosome they inherited from their father.

If the females being tested have the same mother, we will need the DNA sample from the mother for us to run this test. If, in this scenario, the results show a match between the profiles of the tested parties we will not be able to tell whether this match is because of the paternally inherited X chromosome or the maternally inherited X chromosome – unless we have the mother’s DNA sample. If we have the mother’s sample, we can compare and exclude her X chromosome and work only with the paternally inherited X chromosome.

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*A Short Note About Accuracy

X chromosome testing is accurate but one should consider the possibility of mutations arising on the X-chromosome that would result in the different regions appearing as mismatches for a case of genuine paternity/relatedness. In this case, the presence of two mismatches is not sufficient to exclude the two individuals from sharing a father, however the odds that two mutations would arise over one generation (especially for males donating an X-chromosome) are very low.  Therefore we give such a case an inconclusive result. A perfect match and the females share the same father. 3 or more mismatches and we can conclusively exclude that they share the same father.