JustAnswer Blog: Health

You are here

Can a paternity test be wrong?

Man getting swapped wonders: can a paternity test be wrong?

Swab and blood testing are the popular ways of determining paternity.

Can a paternity test be wrong?

By Dhanesh Misir on July 12, 2018

For reasons both legal and otherwise, it’s critical that you can rely on their results. But can paternity tests be wrong?

Nowadays we don’t take much for granted – no matter how concrete something like a DNA test result might seem, there will always be some level of doubt involved too. Was there a mistake made? Is an inaccurate outcome really so unlikely? And what types of factors would be able to throw a test off to the point of shifting its results from dependable to debatable? 

One question asked at some point or another by many people dealing with child support and custody proceedings: Can paternity tests be wrong?

Aside from those used for criminal investigations, there aren’t many DNA test options that carry as much weight as the ones used to determine parenthood. It’s been found that home DNA tests provide false results at a fairly high rate, but is this the case for all tests? 
 

Paternity test results can be impacted by fraud and tampering

On their own, paternity tests tend to be very reliable – especially if conducted at the right time. Dr. Muneeb Ali, a verified OB GYN Expert on JustAnswer, explains paternity test accuracy:  

“These days, a non-invasive paternity test, which involves taking a blood sample from the mother and a hair sample from the father, is about 99.7% accurate. This is because the test utilizes the latest DNA sequencing to allow some of the baby's DNA found in the mother's bloodstream to be isolated and then compared with the father's. However, it is accurate after 8 weeks of pregnancy. Before that the accuracy is low.” 

Although many of us would love to live in a world where everyone does their job properly, and where people always operate with integrity… that will never be the case. And just like everything else, DNA testing can also be impacted by unsavory characters with agendas of their own. In cases like this, the innate accuracy of a test can be nullified. There have been instances of forensic workers and lab technicians purposely changing results, or claiming to have analyzed samples that weren’t actually tested.  

Another source of DNA indiscretions comes from tampering or dishonesty on the part of an involved party. This can include lying about taking a paternity test, or even interference from the mother. If someone accesses the test when they shouldn’t, they could potentially manipulate the results to show their desired outcome. 

There can be a lot going on in a lab at any given time. 
 

Human error and paternity test results

Nobody’s perfect, and even the most careful, dedicated workers will make mistakes on occasion. This includes the people who handle DNA testing, which raises an important question: can a paternity test be wrong because of a simple mistake? The likelihood of this happening can vary, with much less of a chance in cases with a court or CPS ordered paternity test

Some of the human errors that could potentially alter the results of a DNA test include: 

  • Programming errors – Relying on computers tends to make processes easier, while reducing the odds of a silly mistake interfering with results. However, if there is a programming mistake, the computer won’t know any better, and will continually churn out results based on an incorrect code.
     
  • Compromised samples – Accuracy in the final results depends on quality samples. If a DNA sample becomes contaminated, either via external substances or another person’s DNA, the reliability of the test can be compromised. Careless lab technicians could potentially add their own DNA to the mix without realizing it.
     
  • Clerical errors – Organization is crucial for any functional lab environment, and when someone puts the wrong label on a sample, or mixes up two names, the results of the test won’t be accurate.

Of course, if you enlist the services of a reputable lab, the likelihood of these issues taking place will be extremely low. 
 

Even the most careful lab technicians can’t compensate for potential relations and mutations. 


Paternity test inaccuracy due to relation or mutation
 

Although both prenatal and postnatal paternity tests offer comparable, and reliable, accuracy, there are certain factors that could potentially skew the results. The first instance to consider is when there are multiple paternal candidates who are actually related to each other. Although this is as uncommon as it is awkward (this scenario wouldn’t be out of place on some daytime talk shows), it is technically a possibility. If a child has been fathered by one person, but that person’s brother is tested for paternity, they could be determined to be a positive match. 

Mutations to the paternal candidate’s DNA could also have an impact on the test results. Mutations are a normal factor, and they typically don’t affect a paternity test’s accuracy, but if the mutated DNA is present in the father’s sperm, it could produce a false negative. Beyond that, as men age there are more and more of these mutations to contend with. 

If you believe the results of a paternity test you or someone else has taken are questionable, don’t take any chances. For help navigating your options, or for more information on the question of: “Can a paternity test be wrong?”, take your uncertainties to the Experts on JustAnswer
 

Have you been faced with questionable paternity test results before? Do you have some stories to tell? Share them in the comments section below!