DNA Testing and Paternity Testing DNA Testing Services DNA Testing and Paternity Testing
DNA Testing for Paternity and Immigration Cases
Available on Weekends
by Appointment


Contact Us

About DNA Testing
How to Interpret DNA Paternity Test Results
Created On
Friday, April 17, 2009
Last Modified On
Tuesday, March 22, 2011
Last Modified By

Many people think that a DNA paternity test will give a "yes" or "no" answer. The truth is that it is slightly a bit more complicated than that. In the vast majority of tests, either an "inclusion" or "exclusion" result will be reported.

What an Inclusion Means

An inclusion is reported with a probability of paternity (POP) of 99% or more and a match is found at all genetic markers tested. In an inclusion report, it is stated that the alleged father "cannot be excluded" as being the biological father of the tested child. These three words often create a lot of confusion. This wording is used since an inclusion can not ever be reported at 100%. However, the combined paternity index (CPI) should also be looked at, as it can help to make the results more understandable. First though, it should be understood that the bare minimum for reporting an inclusion result is with a POP of 99% and a CPI of 100 (alleged father and child only) or 500 (alleged father, child and mother). Since our laboratory utilizes an advanced analysis of fifteen genetic markers as a standard, we normally see POPs and CPIs far exceed the minimum requirement. So, when the CPI is say, 100,000, it can be interpreted as a 1 in 100,000 (of the defined male racial population) certainty that the alleged father is the biological father of the tested child.

What an Exclusion Means

An exclusion is reported with a POP of 0.00%. In an exclusion result, it will be seen that at at least two genetic markers, there is a non-match. In an exclusion report, it is stated that the alleged father "was excluded" as being the biological father of the tested child. When an exclusion is reported, a second, independent test will be performed to confirm that the exclusion can be duplicated.

Other Possibilities

Another possible result may be an inclusion with a mutation. In most cases, an inclusion result means that at all tested genetic markers, a match is found. However, sometimes an inclusion can be reported when all but one marker has a match (or, in rare cases, two). Known mutations have a specific frequency in various racial populations and, often, that frequency is low. So, when the mutation frequency is figured into the formula for calculating the POP, it can possibly cause the POP to fall below 99%. To confirm mutations, it is always recommended that the mother test, if she has not already, or to perform extended testing of additional markers.

Print This Page
Sample Collection  
Request Info  
Contact Us  
"I just want to thank the continued professional and courteous service your Customer Service team provided me during the stressful waiting period for the DNA results. I contacted both your phone support and instant chat support teams at least twice and received concerned support each time. Never did I feel like they thought I might be calling too much and needed to be more patient. I truly appreciate their consideration and patience during this time."
  More Testimonials  
Legal | More Resources | Terms & Conditions | Privacy Policy | Links | SiteMap | All Rights Reserved By 800DNAEXAM.com © 2006