Y-STR Testing can be the right option for you!
Y-STR, or Y-Chromosome testing is commonly used in ancestry cases where there are two males wanting to determine if they are related. The Y chromosome is passed from male to male in patrilineal ancestry, therefore only works when two males are being tested. With a very slow mutation rate, the Y chromosome remains virtually intact and unchanged when passed from father to son.
Genealogical testing has become an accurate and affordable way to determine if a biological relationship exists when two people were previously unsure. Like other DNA testing, the Y-STR can be done through a simple cheek swab, or buccal swab. Companies like Paternity-USA offer affordable pricing, which makes the test more accessible to serious genealogic researchers, or to families who are just trying to find out if they are related.
Y-STR results are given in the form of a percentage. The test can only be performed between 2 males. The result does not give you the exact relationship, for example whether the two tested individuals were father/son, grandfather/grandson, etc., but rather a percentage of probability that they are from the same male lineage. The result either indicates there is no probability of a genetic relationship or there is a 95% probability that there was a recent male ancestor in common.
The Y-STR test can give a more definitive result than another type of DNA testing like a sibling or avuncular test. An avuncular result could leave lingering questions, especially if the participants are known to have different mothers. However, if the case is with a father and son, the paternity test may be a better option. A paternity result will be either 99.9% positive or 0% negative, and will determine if the tested parties are father and son.
Remember, the Y chromosome is only passed down from male to male and so both participants must be male. If the participants are not both male, another type of DNA testing can be…