In the siblingship DNA test, two individuals are tested to determine whether they share one or both of their biological parents. Full siblings share both of their biological parents and half siblings share one of their biological parents. Universal Genetics provides both full and half siblingship DNA tests. Sometimes, the immigration authorities may request immigration applicants to take a siblingship DNA test in a petition based on the claimed sibling relationship. The test can also be used to confirm paternity indirectly in cases when the alleged father is not available for DNA testing. The chain-of-custody DNA test results can be used as legal evidence in inheritance, social security benefits, and other legal situations.
Since siblings have the same parent(s), the odds of them sharing the same genes are much higher than two unrelated individuals. A siblingship DNA test discovers these DNA matches and determines the probability of relatedness by statistical calculation. Mother(s) are always encouraged to participate in the test (if she is available) because it helps exclude her genetic contribution making the comparison easier.
If the two individuals know that they share one parent, a half siblingship DNA test will be conducted to find out if they share the other parent.
DNA tests for siblings usually show a number of genetic matches in true biological siblings. In these cases, the test results may show the probability of siblingship to be up to 99%, which conclusively proves the biological sibling relationship. In some cases, a siblingsship test can lead to inconclusive results. However, testing additional family members can help to improve the conclusiveness of this DNA test.