When questions arise about familial relationships like paternity, DNA testing can provide clarity and peace of mind. A Y-STR test is a specific type of test that validates male lineage, such as father-son relationships. Find out how it works below.

What Is Y-STR?

The “Y” refers to the Y-chromosome that is passed from male to male. STR stands for short tandem repeat, which is a portion of DNA with certain unique patterns that are repeated anywhere from five to 50 times. Two men from the same paternal lineage will have the same Y-STR DNA profiles.

A Y-STR test conclusively confirms whether two or more males are from the same genetic line. Basically any male relationships on the father's side can be confirmed, provided the line of lineage is unbroken. This test does not determine the precise biological connection, however. For example, it can't take the DNA of two men and determine which one is the father and which one is the son. It can simply establish that the biological relationship exists.

The next step could be relationship testing for a more conclusive result.

How Does It Work?

This DNA testing process is painless and doesn't even require a blood sample. A so-called “buccal swab” is taken from the inside of the cheek. These cells contain DNA, which are then tested in a lab and compared to the other male’s DNA sample. If the Y-STR profiles match, there is a biological link.

AccuDNA of Saint Louis, MO, performs fast and accurate DNA testing, including familial relationship testing for siblings, parents, and grandparents. All it takes is a painless swab of cells from the inner cheek. Their friendly team will walk you through the process and answer any questions you may have. They operate on an appointment-only basis and will work around your schedule to accommodate your needs, opening earlier or staying later as needed. Learn more about the types of testing they offer on their website. To schedule your appointment, call (314) 845-9997.