Interpreting A DNA Relationship Test Result

Unlike a DNA paternity test, which will always provide a conclusive result, relationship tests are different as they involve the comparison of less direct relationships than those between parent and child.

When such a test is conducted, the laboratory will determine the genetic profile of the alleged relatives based on the type of genetic information exhibited by each person. The comparison of these profiles will generate a relationship index known as the Combined First Order Index that is then reported in your DNA test together with the Probability of Relationship.

The result of the Combined First Order Index can be used in the following manner to interpret the results:

If the number is less than 1, it is unlikely (<50%) that a biological relationship exists between the individuals tested. If the number listed is equal to 1, then a 50% probability exits that they are biologically related. As the number increases, so does the percentage probability of a relationship. When the number reaches 100, the tested relationship is highly probable, practically proven.

easyDNA will always aim to try and achieve a Probability of Relationship giving an inclusion of 99% or an exclusion of 0% - however this is not always possible and will depend on how unique is the DNA of the persons tested and who is actually tested. We normally take a range of 80%+ for an inclusion and 25%> for an exclusion.

Therefore, although the relationship test does not guarantee to always provide you with a conclusive answer, it may be able to provide you with an indication of whether you are more likely to be or not to be the true biological relative of the other tested individual.