When we receive tricky questions, like this one below, from concerned parents we reach out to experts to help us answer them whenever we can.
In many cases, knowing exactly who the father is can make an enormous difference in a child's life. Once paternity is confirmed, maintenance can be paid, assuring the child of a more promising future.
But some father's, looking to avoid the responsibility perhaps, deny their paternity, and this is where paternity tests come in. But what to do when the test outcome is in dispute?
We asked the experts at Next Bioscience to assist this reader with her concern:
In 2006 when doing the DNA test for my daughter, 14 Genetic Markers were tested.
12 came back as a match to the father. 1 was common to both of us and 1 was negative which gives the test 98% probability. The doctor told us that the child was not the alleged father's.
I asked him further about the meaning of 98%, because it’s supposed to be 0 if it’s not his. The doctor told me that the child could be the man’s twin/ brother or father. That’s not true because the man is the only son at his home and his father died long ago.
Now the man stopped taking responsibility for his child.
Please help me.
First, what is paternity testing?
DNA paternity testing determines the biological father of a child, explains Kelly Loggenberg, a Genetic Counsellor at Next Biosciences. "We all inherit our DNA from our biological parents — half from our mother and half from our father," she told Parent24.
A DNA paternity test compares a child’s DNA sequence with that of the alleged father to determine if there is a match.
A standard paternity test involves a small blood sample being collected from the child and alleged father, under certain conditions. The turnaround time for results is usually 2 weeks.
How accurate is a DNA paternity test?
Using DNA to test the paternity of a child is the most accurate method available, Loggenberg says. This method can determine to about a 99.9% accuracy whether an alleged father is the biological father of a child.
"If the DNA profile between the child and the alleged father match on every DNA marker pair, it can be calculated that the probability of paternity is 99,9% or greater," she explains.
If the alleged father does not match on two or more DNA marker pairs, she told us, it can be determined with 100% accuracy that he is not the biological father.
Can results be admissible in legal proceedings?
In order for paternity tests to be admissible in court, the testing procedure must follow strict chain of custody, which governs the process for sample collection and identification of the tested parties.
"Chain of custody involves a sample collection that must be done by an independent person which is either a doctor, registered nurse or by someone who is in the presence of a local magistrate, GP or lawyer," Loggenberg says, "Every step of the sample collection process must also be documented."
Each test participant needs to supply the original and a copy of their identity document or a birth certificate for a child. The mother or legal guardian will sign on behalf of a child that is below 16 years.
If samples are collected and testing is done under chain of custody requirements, the results can be used to settle child custody and support cases, inheritance disputes and for immigration applications, she says.
Is the baby his?
“Without seeing the report that was issued, it would be remiss to give a response as it has such significant implications for the person. I suggest that she have a genetic counsellor review the report or request an interpretation from another doctor,” Loggenberg suggests.
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