DNA Grandparentage Test

In situations where the alleged father is unavailable for testing (e.g. alleged father is deceased or unwilling to participate), the alleged father's parents can be tested to determine whether they are the true biological grandparents of the child. When conducting a grandparentage test, it is recommended to test both grandparents (the grandmother and the grandfather) in order to obtain the most conclusive results. If this is not possible, a grandparentage test can be conducted by testing only one grandparent.

Testing the grandmother, grandfather, and the grandchild:
When both of the alleged father's parents are available for testing, the laboratory will examine the genetic profile of both grandparents and then use the genetic information of the grandparents to reconstruct the genetic information of the missing alleged father. Once the alleged father's genetic information is reconstructed, a paternity analysis will be conducted by comparing the reconstructed genetic information for the missing alleged father against the genetic information of the child.

Testing only one grandparent and the grandchild:
In some situations, only one grandparent is available for testing. When only one grandparent is tested, the missing alleged father's genetic information cannot be fully reconstructed. In such situations, the laboratory will test the single grandparent and the grandchild and then compare their genetic information. Based on the type of genetic material expressed by each individual, the number of genes which are shared, and the pattern of expression of the genetic material, the laboratory will be able to perform a statistical analysis to generate the "grandparentage index¡¨. If the grandparentage index is less than 1.00, this indicates that it is more likely that the grandparent and grandchild are not related. However, if the grandparentage index is greater than 1.00, this indicates that it is likely that the grandparent is biologically related to the grandchild.