What Are the Causes of False Positive DNA on Paternity Tests?

By Editorial Team

Updated July 21, 2017

Mother and father swinging daughter


While the odds of a paternity test yielding a false positive result are rare, it is possible. Any man who has been named as the father of a child through paternity testing may wonder about the validity of the result.


There are two main methods of DNA testing. According to the Separated Parenting Access & Resource Center (SPARC), Polymerase chain reaction (PCR) uses swab samples and yields faster, but less accurate, results than the older method, fragment length polymorphism (RFLP), which usually uses blood samples.


Different laboratories will have different levels of accuracy based on how many genetic markers they test for. A 99 percent accuracy rate is much less reliable than one of 99.99 percent, which is what SPARC, a nonprofit organization, recommends.


The problem with tests that look for fewer genetic markers is that there may be other people who share the same markers as the potential father in question, and thus, a possible false positive result.


Many people think they must wait until the baby is born to test paternity, but according to the DNA Diagnostics Center, this can be tested as early as 10 weeks into the pregnancy.


According to the DNA Diagnostics Center, less expensive tests, in the $99 range, may use techniques that are not within the industry protocol and thus might not stand up in court.