Is this person my sibling?
DNA Testing is the only way to be certain.
The most common use of this test is to help curious individuals find out if they are siblings. This is sometimes among potential siblings who have been long-separated by adoption, divorce, or other circumstances. It can also help answer questions in paternity matters where the father of one of the potential siblings is known.
Sibship testing is not as certain as paternity testing or even grandparentage testing when no known parents are available for testing. The test is still highly accurate, it is simply a matter of being able to calculate the “sibship index”. Generally speaking, a higher sibship index indicates higher probability of sibship, whereas low index is lower probability. The problem is that it is possible to have false positives or false negatives. The results of this test are best combined with other information or evidence of sibship to be certain. More information is available in our frequently asked questions section.