DNA Tests Available > Sibling DNA Testing
Sibling DNA testing is used as an indirect way of establishing the identity of biological parents. The sibling test analyses the participants DNA to determine whether they have any biological parents in common. The sibling test should only be used when the parents in question are not available for testing themselves
Do we have the same father?
Are we full siblings or half siblings?
Are we half siblings or unrelated?
We have the same mother but do we have the same father?
There are typically four types of Sibling DNA Test, depending on the situation known:
At DNA Clinics, a Clinical Advisor will work with you to establish exactly what the situation is and what the known facts are, thus determining the correct form of sibling test for your family.
If a KNOWN parent is available for testing, then they will be included in the test for FREE as this may increase the overall accuracy of the test.
The test analyses up to 34 genetic locations on the DNA strand to create a DNA profile for each test participant. The DNA profiles of the test participants are then compared.
The advanced sibling test begins by analysing 20 DNA markers. The number of markers is then increased as required until the greatest level of conclusiveness is achieved.
The test is based on the fact that biologically related individuals should have more DNA in common than unrelated individuals. On average the DNA of full siblings will match at more DNA locations than half siblings, and half siblings will match at more DNA locations than unrelated people.
In order to determine the most likely relationship between the individuals tested, complex statistical analysis is carried out on DNA profiles generated. The values from the calculations are used to generate a percentage probability value. For example, if two individuals want to know if they are half or full siblings, the percentage probability will indicate which relationship is most likely to exists.
Sibling DNA tests are usually a way of testing the identity of a biological parent, without directly including that alleged parent in the test.
Although Sibling tests can be very accurate and useful DNA tests, they cannot replace the tests that directly test the DNA of a biological parent. For example, if an alleged father is available for testing, then a Paternity DNA test should be used rather than a sibling test.
In some instances, where both siblings are male, testing using another type of DNA test called a Y-chromosome test may provide useful evidence of the relationship. This type of test can confirm conclusively that two males do not share the same father or that the two males belong to the same paternal line.
While these tests can provide accurate results, there is a small chance that the test will yield an INCONCLUSIVE result.
Inconclusive results are not the same as negative results. Inconclusive results mean that the laboratory analysis cannot determine the answer to the question posed by the client.
An INCONCLUSIVE result occurs in only 1% of sibling DNA tests (i.e. 1 in 100).
All of the DNA markers that show matches between test participants are very common within the relevant general population. In these circumstances the matches do not provide the required genetic evidence to confirm which biological relationship exists.
There is a low level of DNA matches between the DNA profiles of the participants due to the chance nature of inheritance in families.
Where matches may have originally occurred, mutation has changed the DNA marker and caused mismatches at further locations within the DNA profile.
If any of the parents of the siblings who are being assessed are available for testing, this will aid the analysis and may increase the certainty of the result.
As in a paternity test a DNA profile is produced for each person made up of a number of DNA markers. The DNA profiles of the two people are then compared.
On average full siblings will share more DNA markers than half siblings, and half siblings share more DNA markers than unrelated people. The statistical analysis performed will determine the most likely relationship given the DNA results.
DNA Clinics provide all Advanced Sibling DNA tests in a clinical setting with one to one consultation and full support through a dedicated case manager for both peace of mind and legal DNA tests for siblings. Call DNA Clinics now to arrange an appointment.
The DNA samples for your Sibling test can be taken by a DNA Clinics registered nurse in the comfort of your own home or at another location of your choice. Call today to discuss your DNA test appointment options.
These DNA test kits allow you to take your own DNA samples in the comfort of you own home. Call and order a Home DNA Test Kit today or visit our on-line store to order your FREE DNA Sibling test kit.