DNA testing brothers for paternity

AlphaBiolabs often gets asked the question: can a DNA paternity test be performed without a father being involved? The answer is no….but read on.

It is illegal to obtain a DNA sample from a father for testing without his knowledge. All testing laboratories require written authority from all adults whose samples are provided for testing. Our Peace of Mind DNA relationship tests require signed consent forms, which are included in the testing kits.

However, you may be able to get the answers you need by using alternative routes.

DNA testing brothers can prove paternity

If a father refuses to consent to a DNA paternity test, alternative DNA relationship tests can be performed to establish a direct biological relationship via other family members. Sibling DNA testing, for example, can DNA test sisters or brothers to establish whether or not they have the same father.

Firstly, a DNA sample needs to be collected from both siblings. This is a simple process and just involves rubbing the inside of their cheeks with a swab to collect cheek (buccal) cells. The DNA is extracted from the cells when these swabs are returned to our Warrington-based laboratory. Our in-house DNA experts then use statistical analysis to evaluate the amount of DNA shared between the two siblings.

Another DNA test, which could answer your question is Y chromosome testing. This test can prove that brothers share a common paternal line. All male children inherit their Y chromosome from their father; these children will in turn pass the Y chromosome inherited from their father to their children when they become fathers. A full match between tested brothers confirms a shared paternal line.

Other forms of DNA testing can also prove paternity

Alternative DNA relationship tests can also be used to get the answer you need. Grandparent DNA tests can prove a link between an individual and one or more of their father’s parents. Since a child inherits half of his or her genetic profile from each biological parent, when a child’s father is unavailable for testing, we can test the grandparents to determine if they contributed DNA to the child’s genetic profile.

In the same way, aunt or uncle DNA testing can be performed on a father’s sister or brother to establish a biological relationship to a child.

If the father has only recently passed away. There is another method that could be used but which would require consent from the next of kin or another qualifying relative. A viability study can be used to analyse the deceased’s toothbrush (see toothbrush DNA testing) to see if a DNA profile can be achieved. If DNA can be analysed, a paternity test can be performed in the usual way. 

If you’re unsure on which DNA relationship test is right for your particular case, please call our Customer Services team on 0333 600 1300; email: info@alphabiolabs.com