X-Chromosome Testing between Sisters

Sisters may be unable to carry out a paternity DNA test if the father is deceased or unwilling/unable to be tested. An X-chromosome test will in such cases allow you to establish whether you are:

• Half sisters or full sisters
• Half sisters or not sisters at all

It is important to note that we always advise doing a paternity DNA test where possible rather than the X-chromosome test as the testing procedure for the X-chromosome is more complex and thus, more expensive.  Results for a paternity test are also more direct and conclusive.

The X chromosome test is based on the fact that females receive one X chromosome from the mother and the other from the father. Therefore in the case where two sisters have different mothers, we can do an X-chromosomes test without the need for the sample of the mother. The X chromosome test will therefore seek to establish whether they share the same X chromosome thus concluding they share the same father.

Two sisters that share the same mother and want to establish whether they are full siblings or half siblings will need to include their mother’s DNA sample alongside their own to be able to conclude the test. We will need to map the X chromosome pattern in the mother’s DNA sample and exclude this from the sisters’ DNA profile. We can then compare the remaining X chromosome pattern on the sisters’ DNA and if it matches it will indicate that they likely inherited it from the same father. If the mother’s sample is not available then a Siblings STR Test is recommended.

The cost of an X-chromosome test for two sisters is $399.00 with you results ready in 14 -21 working days. Proceed and Order Here your test. Alternatively read more about other types of Relationship DNA tests.