About Family Relationship DNA Results
Attempting to answer the question of paternity without testing the alleged father can be performed with accurate results in a high percentage of cases. This includes testing full or half siblings, a paternal grandparent, or a sibling of the alleged father (aunt/uncle). However, there is a possibility of obtaining inconclusive results. We cannot predict if your results will be inconclusive. An inconclusive result is the product of the statistical comparison and not the DNA test.
We use the unique DNA profiles of the suspected relatives to calculate how likely they are to be related versus being unrelated. This statistical comparison is an attempt to approximate reality and is expressed in percent probability. In all cases, it is beneficial to include the mother since she donated half of the child’s DNA. This will allow us to focus on the paternal DNA in the child and will decrease the likelihood of getting an inconclusive result.
When we do not have the father to test, we are relying solely on the statistics of a relative that did not contribute DNA at every marker like the father would. When attempting to answer the question of paternity without testing the alleged father by using a close relative, there is a possibility that the outcome might be a misclassification of the relationship. Again, it is beneficial to include the mother since she donated half of the child’s DNA to limit the possibility of this happening.