The CPI represents the total likelihood that a person is related to the other person in the exam. It can’t be 100% because identical twins exist, so there’s no way to say with absolute certainty that two people are related. [3] X Research source The maximum potential CPI is 99. 9999999998%, although most DNA tests will not provide that many decimal places. [4] X Research source
A result indicating that you’re related to the child may simply say “inclusion,” “John Doe is not excluded as the biological parent,” or something similar. A result that says you aren’t related to the child should read “exclusion” or “John Doe is not included as a biological parent. ” DNA paternity tests are 99. 9% accurate, so don’t write the results off if you know for a fact that the samples were provided from the right people. [6] X Trustworthy Source Cleveland Clinic Educational website from one of the world’s leading hospitals Go to source
An allele is a variation of a gene. If you and a partner give birth to a child, that child will get 1 allele from you and 1 allele from the other parent. So, for one locus, a child may have alleles 12 and 20. If you have 20 and 14, it can be presumed that you the child got that 20 allele from you. This is a match. If you had 17 and 14, it would not be a match. Go through each row and count the number of matches. Take the total number of matches and compare it to the conclusion and CPI. If you have 15 out 15 matches, the CPI should be 99. 99% or more, and the conclusion should say something like “inclusion. ”
In other words, a result of 13/15 matching alleles that results in a CPI of 40% or so does not mean that you aren’t related to the person.
No DNA test will contain more than one father or more than one mother. It will always be one father and one child, or father, mother, and child. If you see more than one child or father listed in the results, it’s almost certainly fake.
In the United States, the lab should be licensed by the AABB (American Association of Blood Banks) and/or CAP (College of American Pathologists). If the lab results have no source and/or the lab isn’t accredited, the results are unlikely to be reputable or valid.
Many DNA testing labs will provide sample reports that walk you through how you’d interpret the results. The two biggest DNA testing services in the US, Quest Diagnostics and Labcorp, both provide sample reports on request.
