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Can a Paternity Test Be Wrong?

Posted on in Paternity

California divorce lawyer, California family law attorneyWhen establishing paternity, or lack thereof, there is a chance that a “paternity test” or a DNA test will become a necessity. In some cases, one or both individuals receive an unexpected response, leaving them left to wonder the validity of the results and how it affects their case. Can these tests give incorrect answers?

The short answer is “yes.”

Can a test be wrong? Absolutely. No test is 100% accurate all of the time. There are paternity testing labs that do each test twice to ensure the validity of the results, however not every company does this, even some of the accredited facilities. Although there are several methods for running the comparison, the simplest and most non-invasive solution is collecting a DNA sample through a cheek swab of both the child and the potential parent. Scientists at the lab review the DNA strands within the sample.

Each person has a unique DNA sequence, except identical twins. We get our DNA from our parents, half from each biological parent, so there will be significant similarities. Without comparing the nearly three billion base pairs of each human genome, no one can 100% be excluded as a father. However anyone related will have a similar sequence throughout. Standardized testing includes 15 markers out of the entire DNA sequence, of which ten must match to establish parentage.

Situations in Which You May Want to Retest

Unfortunately, it is never blatantly obvious of an error in the test. If you believe in your heart that you know the truth, then, by all means, have the test completed again, perhaps with a different facility. Errors may happen, although not typically given correct samples. The primary source of a "false inclusion" or "false exclusion" is due to human error, in which someone, somewhere, mixed up the DNA samples. Other situations in which an error is a possibility include:

  • The potential fathers are identical twins,
  • The fathers are related,
  • DNA mutation,
  • Chimerism (a rare condition in which the father has two sets of DNA),
  • Contaminated sample, and
  • The father had a friend do a swab.

If in Doubt, Get Tested Again

If you had the test done not through a court order, there is a higher risk of a mix-up. For instance, if you allowed your partner to complete the test at home, they may have accidentally or intentionally contaminated the results. However, results may be wrong even in a court-ordered test, although they typically have a 99% or higher accuracy rating. Therefore, when in doubt, test again.

If you want to establish or deny paternity, it is important to have a lawyer aiding you in understanding the results and what that means for you and your child’s future. If you would like to discuss your situation with a San Jose, CA paternity attorney, contact the Law Offices of Benita Ventresca today by calling 408-395-8822 to schedule a free initial consultation. Attorney Benita Ventresca has 35 years of experience compassionately assisting clients to achieve the results they desire.



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