How accurate is DNA paternity testing?

DNA paternity testing is 100% accurate when done properly. There are three critical elements to any paternity test: the process, the test, and the lab. At DNA Specialists of Houston, all of our tests meet the standards of the legal system, and we can assure accuracy in every paternity test.

The process: There are three options for paternity testing: standard trio paternity, motherless paternity testing, and non-invasive paternity testing.

Standard Trio Paternity

Participants for a standard paternity test, called a trio, are the mother, child and alleged father. The mother’s participation is always encouraged in a paternity test because we can identify the DNA she passed along to the child, with the remaining DNA to be contributed by the biological father.  The average Combined Paternity Index (CPI) of a trio is 1 million, while the average CPI of a motherless case is only 10,000.

A trio paternity test provides the strongest case for use in the courts, where the mother’s involvement is preferred and sometimes required.

Motherless Paternity Testing

Because DNA testing is so powerful, paternity can be determined even when the mother is unwilling or unavailable to be tested. If the mother is unwilling to be tested but can accompany the child to the collection, request that she provide consent for the minor child. Her signature and consent gives her access to the case with questions or concerns, a copy of the paternity results, and a full chain of custody, if requested.

Although it is possible to determine paternity without the mother, there are unique situations in which the laboratory may require the mother’s sample to be collected. These situations include (but are not limited to) cases with alleged fathers who share a close biological relationship.

Non-Invasive Prenatal Paternity Test

Paternity can be determined using a simple blood-draw from the mother and a buccal-swab collection from the alleged father, as early as 7 weeks' gestation. This non-invasive prenatal test is completely safe for both mother and unborn child and utilizes the Next Generation Sequencing (NGS) to generate results. The technology examines 2,688 SNP (pronounced snip) markers in the DNA to develop the data used to calculate whether or not the alleged father is the biological father of the fetus.

We are able to separate fetal DNA from the mother’s DNA to create a DNA profile for the fetus (cells from the developing fetus float freely in the bloodstream of the pregnant mother); these fetal cells can be detected as early as the 8th week of pregnancy.

The Test: DDC Paternity Test

Your DDC paternity test results report contains the following main sections, with each displaying important information.

  • Genetic System Table (Locus/Allele Sizes chart)
  • Combined Paternity Index
  • Probability of Paternity
  • Test Conclusions

For more information on any of the elements of the report, please visit the DDC website.

The test will conclude with one of two statements:  "is not excluded as the biological father" or "is excluded as the biological father."

If the conclusion states, “is excluded as the biological father,” this means the possible father IS NOT the biological father of the child, since all data gathered from the test do not support a relationship of paternity.

The Lab: DDC

The following information comes straight from our partner, DDC, on the probability of paternity.

“Many laboratories mistake the term accuracy for likelihood (or probability). The Probability of Paternity is a statistical measure of the likelihood of the biological relationship. In the case of an inclusion result (the alleged father is found to be the biological father), the Probability of Paternity could be as high as 99.999% and higher.

All paternity tests will show a result below 100%—to produce a 100% probability, a laboratory would have to test every other man in the world. Instead, the paternity test uses a population database to calculate the probability of paternity. An exclusion result is always 0% because if the genetic profiles of the child and alleged father do not match, there is statistically no chance for the two to be biologically related.”

No paternity test match will ever be 100%.