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X Chromosome Test

X Chromosome Test
  • To verify if two alleged half-sisters (different mothers) share the same biological father. The reason why they must have different, unrelated mothers is the way the X chromosome is inherited: if two women have one X chromosome in common, it would be impossible to know whether it comes from the father or from the mother's side.
    Note: If two alleged sisters with the same biological mother want to know if they share the same father, they will have to send the mother's sample in order to do the X Chromosome Test.
  • Best option for a test between paternal grandmother and granddaughter.
  • If you wish to know if two alleged sisters also have the same mother, or you are not sure if they have different mothers, you will require a Kinship Test.
  • Accuracy of 99.9%.
X Chromosome Test

How is the X chromosome inherited?

Men have one X chromosome and one Y chromosome, while women have two X chromosomes (and no Y chromosome). Men inherit their X chromosome from their mother. Women inherit one from the father and one from the mother. Therefore, the X Chromosome Test can be useful to verify different relationships, on both the paternal and the maternal side.


The price indicated above is the final price for the analysis of 2 people with standard samples. If the mother's sample is needed, it will be tested at no additional cost (for 1 mother, standard sample).

If you are unsure about whether this test is the best testing option for your case, please contact us. Please remember that, if there is a blood relationship between the fathers/mothers, this analysis may not be the adequate procedure for you; please, contact us before ordering your kit.

You have 2 purchase options:

  • Pay for the complete test now and receive the kit by recorded delivery mail at no extra cost. The kit is sent with a tracking number and delivered upon signature.
  • Pay only a £19 deposit (deductible from the test price), and receive the kit by normal post. Pay the remainder when you send in your samples.

Can't send a mouth swab?

DNA mouth swabWe can test other types of biological samples if you cannot send a mouth swab. Send us an email requesing a list of the non-standard samples we currently accept.

Can't wait for the kit to arrive?

DNA testIf you are in a big hurry, and can't wait for the kit to be mailed to you, you can request the paperwork for your DNA test. Fill in the forms and mail in samples taken by a cotton bud.