How To Read The Paternity DNA Testing Result

DNA testing is done for many reasons but it’s primarily used for paternity tests for proof of biological fatherhood. DNA testing is done through a cheek swab to catch certain chromosomes that will be analyzed in a lab and later separated to find the genetic markers.

Each person will have chromosomes inherited from both of their parents, they are called alleles and it provides the identity of an individual. Alleles are DNA segments that a child will inherit one copy of it from their mother and another copy from their father.

After doing a DNA test through cheek swabbing, you will receive the results with statistics that will be hard to read if you don’t work in a laboratory. This guide can provide you with what you need to learn to read a paternity DNA testing result.

Understand what allele means

After obtaining the DNA testing results you will notice that columns are marked with the word “alleles” for the alleged father, child, and the mother, whether she was tested or not, along with numbers. 

DNA testing analysis matches the number of alleles from the child with the parents’ alleles. These alleles are used in parentage analysis as it determines the genetic markers.

For example, if a child has alleles at a locus that are identified as 13 and 16, the results show that the child inherited 16 from his mother, then the 13 has to be inherited from the alleged father.

The analysis of loci

DNA tests use twenty four sites to reveal the DNA sequence or alleles, and each site is called locus or loci for plural. The alleged father will have a matching allele after testing each locus.

The DNA testing result will show numbers in the first column, which specify the 21 loci used during the process. The DNA result often starts with Amelogenin, and that is used to confirm the gender of the DNA sample provider.

Generally, if the alleged father is found to have the matching allele in all of the test loci, then he is the true biological father. Often, if a match is not found at fifteen tested loci, the alleged father is not the biological parent.

Combined direct index

Statistical results are shown on the report for paternity DNA testing that is calculated using the direct index data for every tested allele. This calculation is based on information that has the paternal allele at the locus. The index for the tested alleles will appear below the combined direct index or combined relationship index.

Probability of paternity

The percentage shown under the probability of paternity is calculated to show the probability of the relationship. The percentage represents the likelihood of whether the man, who is the alleged father with the tested alleles, is the biological father of the child or not.

The DNA results of the alleged father must be consistent with the child’s DNA, and it will show in the report if such degree of certainty has been found in the test.