Results for the test

siblings DNA test will indicate whether any of these relationships exist between the people tested:

  • Half siblings vs. full siblings: siblings will have one parents in common or share both parents in common;
  • Half siblings vs. no siblings: brothers and sisters will share just one parent between them and have no genetic relationship at all is they are not siblings;
  • Full siblings or no siblings: full siblings will share both parents; however, if they are not siblings they will have no biological relationship and have no parents in common.

PLEASE NOTE: In the event of a possible pre-existing relationship the laboratory would NOT be able to run a sibling test if you believe your cousin could be your sibling. Please contact us to help you find the right test for you.

Paternity and maternity

Sibling testing is made more complex by the fact that it is aimed at confirming whether two people share a common parent without testing the parent in question. Sibling test results can be very accurate depending on the case. The results will however, never be as accurate as a paternity or maternity test. DNA testing between brothers and sisters is very different to a standard paternity test or maternity test. In fact, when a direct alleged parent-child DNA test is viable, we will tend to suggest a parentage test rather than a sibling test.

Y chromosome testing

If you are brothers and want to know whether you share the same father, choose a Y chromosome test. A Y chromosome test is far more accurate than a siblings test but it can only be carried out between males.

DNA testing sample collection

DNA is collected from inside the mouth using mouth swabs. Our mouths are lined with millions of cells that form what is known as the mucous membrane. Using the swabs we provide inside our kit, an individual can simply rub the swab inside their mouth to collect the cheek cells needed for laboratory analysis. Once the sample collection is done, swabs need to be left to dry and then returned for testing. The kit we will send you includes everything you need to successfully collect your samples.