Grandparent DNA Testing


Grandparent DNA testing most often is required when someone is seeking to establish paternity of a child, and the alleged father is not available for DNA testing. In this case, testing the alleged paternal grandparents (the father and mother of the alleged father) will provide the same answers as a DNA paternity test. Maternal grandparent DNA testing is also possible, but is rarely performed. Grandparent DNA testing can definitively establish the relationship between any individual and their alleged grandparent. Grandparent DNA testing is somewhat more complex than straight DNA paternity testing, but not as complicated as sibling DNA testing. Results from grandparent DNA testing can be obtained usually in two to four weeks.

Single grandparent DNA testing includes only one grandparent, one grandchild, and an optional, but strongly suggested, parent DNA sample. This type of grandparent DNA testing is the least precise, with best case results in the range of greater than 90% (for inclusion, meaning the grandparent relationship does exist) to less than 15% (for exclusion, the alleged grandparent is not related). Duo grandparent DNA testing includes both grandparents, one grandchild, and again, a parent DNA sample if possible. In this type of grandparent DNA testing, results range from 99% for inclusions to 0% for exclusions.

Grandparent DNA testing is possible because half of a child’s DNA comes from the grandparents through their son. The child’s mother is also encouraged to participate in the test so that her contribution to the child’s DNA can be eliminated. Of course, it’s necessary to know that the grandparents are indeed the biological parents of the alleged father. DNA samples for grandparent DNA testing are collected in precisely the same way as most other DNA testing–through the use of buccal swabs rubbed against the inside of patients’ cheeks. If the results do not need to be legally admissible, then at-home collection is possible.

There are other reasons for grandparent DNA testing in addition to establishing paternity without the father’s participation. Grandparent DNA testing may be used by some grandparents to protect their rights. Some states require grandparents to be financially and legally responsible for the children of minor parents. Grandparents in this situation may wish to confirm their biological relationship to the child.

Some grandparents may seek custody of their grandchildren if they believe the children are living in unsafe conditions. Custody cases will usually require verification of the biological relationship. Grandparent DNA testing may also be used to award grandparent visitation rights.

In most family situations, there is great value in a child-grandparent relationship, and if grandparent DNA testing can facilitate forming this relationship, then perhaps it should be considered.