Understanding DNA Test Results
Your Paternity DNA testing results will state clearly whether you are or are not the child’s true biological father. However, you will also see on the result a number of figures and terms which need to be clarified for you to fully understand how we achieve our outstanding results.
80% of our DNA paternity tests are motherless, meaning they are done without the mother’s DNA samples. We suggest however, sending the mother’s samples as these can help clarify her share in the genetic inheritance of the child and provide a stronger result.
The loci analyzed on the DNA samples
DNA is found in most cells in long, twisted strands. It is a highly complex molecule and due to this, scientists will only analyze the relevant parts of the DNA. Each of these specific parts or sections analyzed in DNA testing is known as a locus. Our laboratories take 20 of these loci on each DNA sample. For each of these loci, scientists take into consideration the variations in different individuals, called alleles. Your results will show two alleles for each locus. Thus, for example, one locus on the child’s DNA will be represented by 2 numbers; 12, 18. The same locus analyzed on the mother’s sample will show alleles 18, 9. In this case, we can safely say that the child has the 18 allele from the mother which means that allele number 12 has been inherited from the father.
When seen on your result, you will immediately grasp this simple comparison procedure between genetic loci.
We will show a straight inclusion of paternity if all 20 loci match between father and child. If 3 or more loci do not agree between father and child, then he will be excluded as being the child’s biological father.
The combined paternity index – what is it?
Each locus on you DNA is used in a mathematical calculation to draw up a paternity Index. The strength of genetic evidence is directly tied to the paternity index. Multiplication of each of the 20 paternity indices on each locus will result in a combined paternity index. The Combined Paternity Index (CPI) will help understand the degree of DNA you have in common with the rest of the population. Our results rely on a statistical probability of the tested father being the child’s paternal father and not any other man in a given population of the father’s same ethnic group.
Your results will show both the CPI and the inclusion or exclusion of paternity expressed as a percentage. If the alleged father is the child’s paternal father, then the percentage will be 99.99%. If however, the alleged father played no role in the child’s conception, then the results will show a 0% chance of paternity.
What do most clients look for in their results?
Clients tend to look at the percentage stating inclusion or exclusion of paternity. The table displaying all the alleles may appear superfluous to some, though many may want to fully understand the test.
We provide such thorough and detailed results because we want to show transparency and ease your mind by showing that we are handling you tests in a scientifically reliable and professional manner.
A bit more on the 20 loci tested
We test for 21 loci not 20. However, it is only 20 of these loci that are strictly part of the paternity DNA testing process. Locus number 21 is the amelogenin sex gene, one of the main genes that determine sex/gender of a child.
Our primary reason for testing this gene is to ensure reliability. We want to make sure that the gender on the submission forms are the same as that of the swabs provided. We have had cases were the mother’s swabs were placed in the father’s envelopes; if the amelogenin test were not carried out, testing would continue with analysts thinking they are testing the father’s samples when in fact they are the mother’s.
Such errors could potentially cause problems with the reliability of the paternity test results. Testing the amelogenin sex gene will ascertain that such errors are detected and not interfere with test results.
Your result will clearly state the gender of the people taking part in the test, showing chromosome pair XX for females and XY for males.
Saliva samples and discreet samples
Most paternity DNA tests are done using a sterile mouth swab. Sometimes, people might wish to use a discreet sample which might include post-mortem tissues, a nail clipping, a used Kleenex and several other sources of DNA.
Discrete samples might not always be an easy means of extracting the DNA. Some discrete samples are easy to extract DNA from, others are rather more difficult. We will give you all the necessary information on the discrete sample you plan to use.
Discrete samples might only be a problem in terms of the ease at which DNA can be extracted. Once, the extraction process is done, DNA testing takes place as with any other sample, providing equally high results.
Should you encounter any problems with your DNA Paternity Test result, contact us on info@homeDNAdirect.ca.