A grandparentage DNA test determines whether a couple could be the biological grandparents of a child. It is an indirect way to determine family relationships when an alleged father is not available for a paternity test. Grandparentage test results may be used as proof in Social Security benefit and other inheritance claims as well as in some immigration cases.
In the test, the child’s DNA profile is compared with the DNA profiles of the alleged father’s biological parents. Since a child inherits half of his/her DNA from the mother (maternal side) and half from the father (paternal side), the paternal half should match DNA passed down from the alleged grandparents. The mother’s participation is encouraged to expedite analysis; motherless grandparentage tests take longer to complete because of the extended analysis required.
Single Grandparentage Testing
A single grandparentage test determines if a child is biologically related to a single alleged grandparent. Single Grandparentage testing is a good option when there is only one of the deceased/missing AF parents available for testing.
- The report will indicate the probability of relatedness and a liklihood ratio similar to a reconstruction report. Refer to the relationship page.
- The limitations of this test is that a single grandparent shares only 25% of their DNA with a grandchild. A low liklihood of grandparentage may indicate that the tested parties are not related or indicate that the majority of the genetic information inherited by the missing AF and transmitted to the child did not come from the tested grandparent.
- We strongly encourage the mother to participate so we can account for one half of the child's genetic material and provide a more precise result. However, testing can be done without the mother of the child.
- In scenarios with limited relatives to test, investigate the possibility of utilizing Y-STR or Mt-DNA testing as well.