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What Does an Inconclusive Paternity Test Mean?
Though DNA tests for paternity are guaranteed 99.99% accurate thanks to modern day DNA testing methods and the uniqueness of our individual DNA signatures, there are times when a test may come back as inconclusive. This does not mean that a match for paternity was not found, but rather that based on the DNA presented it was not possible to say with guaranteed accuracy that the DNA was a match. In this article we'll look at some of the reasons this might happen and what the resolutions are for such situations.
A paternity test is done by taking samples of DNA from the child, biological method and suspected father. The DNA of the child is then matched against the biological mother's DNA to eliminate the 50% of the chromosomes that are received by the child from the mother. The remaining chromosomes are those inherited from the biological father. By taking the DNA of the suspected father and comparing it back against these remaining chromosomes the lab can either confirm paternity or determine that no paternity exists.
In rare situations a report may come back from the lab that lists the paternity test as inconclusive for the given subject. Inconclusive tests mean that because of the DNA sample provided, or because of the match against the DNA to the child it could not be confirmed or denied that the subject is the father of the child. This can happen for several reasons: The subject matched on markers in the DNA on one run, and did not on the next; the DNA sample provided to the lab was contaminated and therefore not useable; the lab could not distinguish or isolate the chromosomes from the mother and the child.
When DNA tests for paternity are performed it is actually a series of tests that expand out through a succession of probes into the DNA the number of markers exposed. A positive test for paternity will lead to the lab expanding the number of markers exposed and again attempting to match. In most cases they will do this three times: the initial test, plus two marker expansions. This helps to eliminate any accidental commonality between markers that may be used for the first test plus helps to independently confirm each DNA test.
If during these tests they get markers that match except for one or two oddities this would label the test as inconclusive. In this situation the lab may recommend a more robust DNA test that expands down markers on the DNA even further or they may suggest that new samples be collected and re-submitted.
One other oddity that should be noted here that can return a paternity test inconclusive is in the case of identical twins. If the suspected father is an identical twin then he shares the same DNA as his twin. In this situation it is not possible to tell which of the twins the father of the child is because they share the same DNA. However, in most paternity tests this is not a problem given the absolute uniqueness of the situation.
So what happens after a test comes back as inconclusive? If it is a court-ordered test then it will simply be given again and the number of probes used to expand markers will be expanded. If it is an “at-home” test then you are required to pay for resubmission of samples and re-processing of the paternity test.