Grandparent DNA Testing is a useful test when the father is unavailable for testing, either because he is deceased, or unwilling to participate. The test is simple, effective and painless.
When should I order a grandparent DNA test?
A paternity DNA test is preferred, as it is a first-order relationship. If Dad is not available, a grandparent test can establish whether the grandchild is related. By inference you can determine paternity for the non-participating father. Or ruling it out.
Sometimes a grandparent DNA test result is used to obtain legal benefits such as inheritance or child custody, or even for immigration purposes.
How does a grandparent DNA test work?
Every child inherits half of the genes from each biological parent. That means a grandchild shares 25% of genes from each biological grandparent.
Is it enough if only one grandparent is tested?
We suggest that both the probable biological grandparents — the grandmother and the grandfather — be tested. This is because testing only one grandparent detects only about half of the possible genes of the grandchild.
If this is not possible, a grandparentage test can be conducted by testing only one grandparent. Including the mother of the child in the grandparentage test will help to increase the accuracy of the test.
Testing Both Grandparents and the Child
When both of the alleged father’s parents are tested, the laboratory compares the genetic profiles of both grandparents to reconstruct the genetic information of the missing alleged father. The reconstructed father’s genetic information is compared against the genetic information of the child.
Testing One Grandparent and the Grandchild
When only one grandparent is tested, the missing alleged father’s genetic information cannot be reconstructed. In such situations, the laboratory tests the single grandparent and the grandchild and compares their genetic information. Using that information, the laboratory performs a statistical analysis and generates a “grandparentage index” which is used to determine whether the parties are biologically related.
I am a male child, and my biological father is unavailable. Can I order a grandparent DNA test?
Yes, you can. In case of a male child, the Y-chromosomes are inherited from the paternal grandfather. Y chromosomes are passed on from male to male of the same lineage. However, you should make sure that you are sure about your biological father. If any of the male persons from your father’s lineage other than your father happens to be your father, then the grandparent DNA test results would not be able to distinguish them.
What DNA samples are used for a grandparent DNA test?
Cheek swab samples of the child, the father, and the father’s parents are the most common specimens used for the grandparent DNA test.
If a cheek swab is not possible, some alternative specimens can be used.
Can I order a grandparent DNA test without my father’s knowledge?
You may. However, we do require written consent that you have the right to order the test.
What if the individuals to be tested live at different addresses?
If the individuals to be tested live in different cities, or even different countries, each specimen can be collected individually and compared once the lab receives them. Please let us know this when ordering.