It is very understandable that the paternity test works a lot like other genetic tests, such as discovering distant relatives, genetic disorders, and ancestral origins. Short Tandem Repeat(STR) in DNA paternity testing is a very reliable option to establish a father and child relationship. Using current technology, you can expect nearly 100% accuracy.
The main thing about Paternity testing is that it can be done very early, even during pregnancy. In this case, the test will be conducted at a hospital and the DNA samples will be collected in one of two ways as mentioned below:
The STRs are typically two to four letters long and just repeat over and over. Remember that, because these regions mutate from time to time, they vary in length from individual to individual.
You can say that they can act as a “genetic fingerprint,” because every person is going to have the same STR segments, but the combination of STR lengths an individual inherits will be unique. Additionally, the main thing is that 50% of a child’s DNA comes from his/her father, which means approximately 50% of these STRs are shared between them. Still, further study of STRs is needed to understand their biological functions.