Following paternity testing accreditation guidelines, results are reported with one of three possible statements. For example, if we tested Mr RA, alleged father, and SS (child), our paternity test results report might say one of the following:

Mr RA is excluded as the biological father of SS.

This means that Mr RA cannot be the father of SS because the analysis shows that they do not share a paternity relationship.

Mr RA is not excluded as the biological father of

SS.

This means that Mr RA is highly likely to be the father of SS because the analysis shows that they share a paternity relationship.

Why does the report say "not excluded" if the person is the father? With DNA paternity testing it is possible to 100% exclude someone as the biological father. However, the only way to produce a 100% positive result, would be to test the entire genome of an individual - all of their DNA. DNA paternity tests use a standardized sample of DNA - up to 16 DNA markers - to predict the probability of paternity. These probabilities are usually very high - as high as 99.9999%. This means that, for an alleged father who is "not excluded", the paternity report is 99.9999% confident that he is the biological father.

What is Paternity Index

This value equals the odds that the alleged father is the biological father rather than any other man selected at random from the population. The minimum PI issued by us is 100 to 1.

What is Combined Paternity Index

Since the result at each Genetic System is an independent event, this value is the product of the Paternity Indices and indicates the possibility of the alleged father being the biological father relative to any other man selected at random from the population.

What is Probability of Paternity

This value is converted from the "Combined Paternity Index" into the percentage probability.

What is Prior Probability

The prior probability in a paternity test is 0.50 which is 50%. That means that, without testing any of the parties, there is a 50% chance that any untested man is the father and a 50% chance that he is not the father.

What is DNA Profile

A DNA test profile is a set of DNA markers (up to 16) used to determine paternity and identity. Geneticists developed this set of markers for consistency in identifying individuals and named them according to their chromosomal location. Each marker location (or "locus") shows two alleles (or variations values), represented by numbers on the report. In this case the alleles are simply measures of short tandem repeats (STR. One of these STR alleles comes from a person’s father, one from their mother.

In a DNA paternity test, the analysis seeks matches of allele number values between the alleged father and child. Because the child must receive one STR allele from his father at all locations (or "loci"), there should be matches for each marker. (In some cases there are natural mutations, where the child has a slightly higher or lower value than the father, but these are somewhat rare. For this tutorial, we'll assume no natural mutations exist.)

An alleged father can be excluded as the biological father with as little as one mismatch between DNA profiles. When a person is excluded as the father, the profiles often reveal several, if not many, mismatches. In the following example, the 3 mismatches would exclude the alleged father (he could not be the biological father). Even though there are also 3 matches, these matches are random and do not indicate a paternity relationship. Almost any two people will have at least some matches, but a father-child relationship will show matches at all locations.

Locus Alleged Father Child Parentage Index

D2S1338 12, 13 8, 9 0.00

D2S1358 8, 11 13, 14 0.00

D8S1179 21.2, 32 19, 21.2 0.675

D10S1008 7, 12 15, 18 0.00

D14S1537 9, 14 11, 14 0.797

D19S433 15, 18 12, 15 1.338

While most DNA paternity tests reflect this "text book" example, there are many other factors to be considered. For example, natural mutations sometimes present more complicated results. Sometimes father and child share many common alleles and though there are many matches, the CPI value is not strong enough for a conclusive result. In most of these cases, including the biological mother significantly strengthens the test results. OTS & Services is a most trusted source of DNA Paternity Test India to offer reliable and most accurate results in India.