It is widely believed that DNA test will provide a simple “yes” or “no” result, however, the truth is that it is more complex than that, with a large majority of tests ending in a “inclusion” or “ex
It is widely believed that DNA test will provide a simple “yes” or “no” result, however, the truth is that it is more complex than that, with a large majority of tests ending in a “inclusion” or “exclusion” result.
Interpreting A DNA Paternity Test
In most cases a DNA paternity test will provide a conclusive result. An alleged father will either be “excluded” from paternity or “not excluded”. The tests are based on the analysis of 15 genetic loci, each compared separately to obtain a paternity index (the 16th loci is the Amelogenin sex loci to confirm the sex of the donor). These indexes are then combined to produce a Combined Paternity Index (CPI).
What is the Combined Paternity Index?
A Combined Paternity Index (CPI) is derived from the Paternity Indices obtained for each genetic locus tested. The CPI represents the Probability of Paternity (POP) and is calculated on the basis of how common the genetic information found in your analysis is compared with the general population. The CPI can result in a 99.99%+ Probability of Paternity. Both the CPI and the Probability of Paternity should be quoted in a paternity test result.
What Does ‘Inclusion” Mean?
An inclusion is normally reported with a probability of paternity of 99% or more and a match is found at all genetic markers tested. An inclusion report will state that the alleged father "cannot be excluded" from being the biological father of the tested child. These three words often create a lot of confusion and unease, however, it must be noted that a result will never due to scientific reasons report an inclusion at 100%. One must always look at the combined paternity index (CPI) to help make results more understandable.
To make things clearer, it should be known that the absolute minimum to report an inclusion is a POP of 99% and a CPI of 100 (alleged father