Siblings DNA Test

From £199

Order Now!

Are you looking to determine whether someone is really your brother or sister? Are you unsure whether you and your brother/sister share the same biological parents? Who’zTheDaddy?™ offer a siblings DNA test to clients looking to answer these questions. This test is recommended when the alleged siblings are a male and a female who would like to know whether they share one or more common parents. Our sibling DNA test for two alleged siblings starts from £199 with results in only 5-7 working days from the receipt of samples.

Science behind the test

The siblingship test relies on statistical probability in that it establishes the amount of common DNA between two alleged siblings. This determines whether siblings share one parent (half siblings), share two parents (full siblings) or that there is no biological relationship between the tested people. Including one known parent of either of the people being tested greatly increases the accuracy of this type of analysis. If this is not possible, disclosing that siblings share a common mother or father can also lead to more meaningful results.

The siblings DNA test results are expressed as a percentage probability of the relationship existing or not, with a result returning in excess of 90% probability being considered conclusive that the relationship (full or half siblings) exists, or less than 15% probability if it does not.

Test results are intended to provide a statistical likelihood that gives evidence to support the tested relationship in question. Providing additional parties to be tested (for example, a known parent’s sample) or performing direct relationship testing may provide additional evidence.

Who’zTheDaddy?™ strongly recommend sending the sample of a known mother if possible as this can help us obtain a more conclusive result.

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.

Y-STR Male Lineage Testing

Who’zTheDaddy?™ offer Y-STR Male Lineage Testing. This type of siblings DNA test is an extremely accurate test and used to determine whether 2 males share a paternal line. Y chromosomes are passed down from fathers to their male children meaning that this chromosome’s inheritance pattern can then be used to trace back the paternal lineage. The conclusive results provided by this test can allow males to determine if they have a shared biological father, grandfather, or male relative.

Sample Collection

DNA tests from Who’zTheDaddy?™ are very simple and straightforward. In your DNA testing kit you will receive two cotton swabs per person. By rubbing these swabs against the inside of your cheek, you collect the DNA required to carry out the test. These swabs are then packaged in our envelopes and sent to the lab.


What is Siblings DNA testing?

The test is recommended when the alleged siblings are a male and a female who would like to know whether they share one or more common parents.

What is the cost of the Sibling test?

Sibling test for two alleged siblings starts from £199.

When will the results be finished?

Only 5-7 working days from the receipt of samples.

Are you Twins?

Who’zTheDaddy?™ offer twin zygosity testing to determine whether twins are identical (monozygotic) or fraternal (dizygotic). Identical twins share the exact same DNA profile while fraternal twins do not. This test is performed through the use of mouth swabs and can provide extremely conclusive results, with minimum probabilities in excess of 99.99% using state-of-the-art equipment that analyses 16 different genetic markers.

Can we confirm a shared female lineage?

Who’zTheDaddy?™ offer X-SV Female Lineage Tests to individuals looking to determine if they share a common maternal line (i.e. have the same biological mother). This DNA test relies on the unique X-SV DNA profile of each applicant through mitochondrial DNA analysis.

Need help?Live Chat