We are often requested what a DNA Paternity Test result looks like. We have therefore attached below a two samples of the test report. The reports below represent a Motherless DNA Paternity tests and shows the result when there is an inclusion and an exclusion of the alleged father. Of course this is only a sample report (names are ficticious) but should give you a good idea what your result will look like. The wording on other types of DNA tests will vary slightly.
Interpreting the DNA Paternity Test Report
When you perform a DNA Paternity test the result will be conclusive in most cases with the result either confirming that the father is 'not excluded' from being the biological father or alternatively it will confirm that he is 'excluded' with 100% certainty. All our DNA tests are performed by analysis 16 genetic loci. These loci are analysed individually and the resulting index of relationship used to obtain a paternity index. Once all the indices are available they are analysed together to determine the Combined Paternity Index (CPI).
What is the Combined Paternity Index?
The Combined Paternity Index (CPI) is calculated from the Paternity Indices generated from each individual locus and gives an indication of the likelihood of Paternity between the alleged father and child as compared to analysis with the general population. The result of the CPI can go as high as 99.9999%+ but will never be quoted as 100% for scientific correctness. As you can see in the attached sample reports, both the CPI and Probability of Paternity are shown in the results of our DNA Paternity tests.
In the sample result, you an also see that the DNA test report will show on the left hand coloumn each of the 16 loci analsyed. Every person carries 2 copies of a chromosome, one which he inherits from the biological father and the other from the mother. For each loci, 2 numbers are shown (or one in the case where the alleles are identical (homozygous)) representing the size of the allele. These numbers are then used to compare between the persons involved in the testing to see whether they match or not.
Therefore, if the child tested has 2 alleles labelled as 15 and 18, and the mother has two alleles labelled 15 and 17, then the child will have inherited the 15 allele from the mother and the allele 18 from the biological father. Once the test is completed, the analysis will check to confirm if the alleged father has this particulalr allele, and of course to be the biological father the allele must match. The procedure is performed for each loci tested. If the alleged father does not have the matching allele at every locus tested, then he cannot be confirmed as the biological parent.
In the case where there are mutiple exclusions, then then Probability of Paternity percentage is 0% - thereby confirming that the the DNA of the alleged father is not consistent with that of the child and therefore he is excluded as the biological father. If the probability Percentage is consistent, then a result in excess of 99.9%+ is normally obtained.
For your Information, we also Would Like to Point out That:
- although we state 16 loci, one of the actual loci tested (called Amelogenin) is analysed to confirm the actual sex of the person. The CPI analysis is therefore based on 15 loci.
- tests performed through forensic samples such as hair, semen etc do not effect the presentation of the result, since one the DNA is successfully extracted from the sample, the testing process follows the same process as that of the standard swab analysis.
For more information about your DNA test result, or the sample result attached, the kindly email us on email@example.com