The paternal relative (Y-STR) comparison test, also known as a paternal lineage test, can confirm a relationship to a distant relative. This DNA test is often used to provide additional evidence in difficult paternity situations in which the alleged father is not available for testing—indirectly, it can tell you whether or not a child is related to the alleged father’s brother(s) and other male relatives who share a common paternal line.
The testing process is simple—the DNA samples are taken using a painless buccal (cheek) swab, and testing is completed in 10 business days. We can either send you a testing kit to collect your DNA samples at home, or if there are legal implications, we can use a Chain of Custody collection process where a trained professional near you will take your DNA samples.
Y-STR Comparison vs. DNA Testing for Ancestry
Unlike DNA tests for ancestry, the Y-STR comparison test provides scientific confirmation of more recent relationships—for example, if you have identified a possible relative from genealogy research and want to confirm your relationship. This Y-STR comparative analysis will tell you whether or not your Y-STRs are consistent, or not consistent, with the conclusion that you and the possible relative(s) may be related through a common male ancestor.
Comparison Testing in Paternity Situations
In a paternity situation where the alleged father is missing, Y-STR analysis cannot distinguish a specific relationship between males who belong to the same paternal line. However, it is useful for excluding males from an alleged biological relationship. For example, if a male child and his alleged uncle (alleged father’s full brother) are tested, their Y-STR profiles must match. If they do not, then the alleged uncle is excluded (not considered a biological uncle) and the alleged father is probably not the biological father.
Y Chromosome Inheritance
The Y-STR comparison DNA test is based on the fact that the Y chromosome is passed from father to son relatively unchanged through many generations. Because the Y chromosome follows the same father-to-son pattern much like surnames in Western culture, the test has also been referred to as a “Surname Test.”
Although the Y chromosome is only found in males, women can also indirectly participate in a Y-STR DNA test if they are interested in determining their paternal relatives. They would need to ask a biological male relative, such as a father, brother, paternal uncle, or paternal grandfather to contribute a sample for comparison testing with her potential paternal relative or ancestor.
In a Y-STR DNA test, specific locations on the Y chromosome are examined to generate a Y-STR profile for each male tested. Males who are related through their fathers will tend to have the same or similar Y-STR profiles, and males who are not related will likely have different Y-STR profiles.
