Paternity testing to determine a child’s parentage is necessary to a child’s wellbeing and legal rights.
The accuracy of paternity tests results have a probability of paternity greater than 99.0% with an average of 99.5%. If after a standard test the probability is less than 99.0% *additional alleles are used to achieve a greater probability of paternity.
Parentage testing can be performed before the birth of the child in conjunction with other medical or genetic screening, such as Chorionic Villas Sampling or Amniocentesis. Please visit Prenatal Testing for more information.
Maternity Testing
The procedure for maternity testing follows the same principles as a paternity test (See paternity testing for further details). This test is most often performed to complete case requirements for the United States Embassy and the United States Citizenship and Immigration Services, but is also helpful if a child has been adopted or if there is a concern that the child was switched at birth.
Twin Study
A Twin Study is useful for determining whether twins are identical or fraternal. If the twins that are tested are identical, they will have identical DNA profiles. If the twins are fraternal, their DNA will be similar to each other (as in sibling cases), but not identical.
Sibling Testing
Sibling Testing is ideal for individuals hoping to find out if they are Full Siblings (sharing both a common mother and a common father), Half Siblings (sharing only one common parent, either mother or father), or if they are unrelated. If the mother or mothers of the children are available for testing, it is highly recommended that they be tested at the time of the possible siblings in order to increase the genetic evidence, however the mothers are not required to participate.
This test is based on a kinship ratio where the Combined Kinship Index of 1 reveals no genetic evidence for or against kinship; therefore the weight of the genetic evidence is stronger the further away the Combined Kinship Index is from 1.
Grandpaternity Testing
Testing for Grandparents of a child in order to prove the paternity is the second best option besides testing the alleged father. If an alleged father is unavailable for testing, such as cases of adoption, or in the event that the father is deceased, a sample can be taken from both of the alleged father’s parents. The ideal situation for this test is to have the mother, child, and BOTH of the alleged grandparents. With both of the alleged father’s parents included, his DNA profile can be reconstructed and compared to the child’s DNA profile. In nearly every case, these results can yield a high enough probability of paternity.
If only one of the grandparents is available for testing, it is highly recommended that the mother provide a sample as well. Each time a person is removed from the test (i.e. grandparent or mother), the genetic evidence for or against kinship decreases, and can yield a low kinship index. This test (one grandparent only) is based on a kinship ratio where the Combined Kinship Index of 1 reveals no genetic evidence for or against kinship; therefore the weight of the genetic evidence is stronger the further away the Combined Kinship Index is from 1.