What is a Paternity test?    A paternity test is a DNA test that is performed to determine if a particular man is the biological father of a particular child.  Each of us receives half of our DNA (half of our genes) from our biological mother and the other half from our biological father.  In a paternity test, we are asking the question, “Does the alleged father’s DNA contain the genes that the child inherited (or possibly inherited) from its biological father?”  If the alleged father does not possess these genes, then he is excluded (ruled out) as the biological father and the probability of paternity will be 0%.  If the alleged father does possess these genes, then he is not excluded (not ruled out) as the biological father and the probability of paternity, in most cases, will be more than 99.9%.

What is a Paternity Test?

There’s more to paternity testing than meets the eye

For greatest accuracy, we recommend testing the mother’s sample whenever possible, because it allows us to determine exactly which half of the child’s genes came from her (and therefore which half came from the father), and because it provides confirmation that the correct child was tested.  In most cases conclusive results are also achieved when the mother is not tested.  However, such paternity tests present a greater likelihood that an alleged father’s genes may match the child due to random chance, and a lower likelihood that an intentional (deceptive) substitution of a child in the test will be discovered (this can be particularly important in cases where the child is a newborn and/or when the alleged father has not seen the child before).

For most paternity tests, the samples used by the laboratory as the source of DNA are called buccal swabs, which are epithelial cells collected by rubbing the inside of the cheek of the mouth with sterile cotton-type swabs.  Collection of buccal swab samples is non-invasive, completely painless, and can be performed as early as the day of birth.  Other types of samples—such as blood, semen, nail clippings, hair follicles, and prenatal samples—may also be used, but these are only recommended in special circumstances where cheek swabs cannot be obtained.  The results of a paternity test will be exactly the same for tests performed using buccal swabs or blood (or other samples) because the DNA found in our cheek cells is the same as the DNA found in all of the other cells in our body.

What is a Paternity Test Revealing About You?

What is a paternity test revealing about your genetic makeup or predisposition to medical illnesses?   Absolutely nothing.  The genetic tests that are performed in a DNA paternity test do not provide any information about a person that is medically relevant.  On the contrary, the DNA tests used for paternity evaluations consist of DNA sequences that have no known function and that are equivalent to the tests used by crime labs (like those seen on TV crime shows like “CSI”) for identification of criminal offenders.

LB Genetics offers several options for DNA paternity tests, including our legally-admissible paternity tests.  The appropriate testing option for you will depend on your particular situation or needs.  For more information about DNA testing for paternity, please call us today at 1-714-648-0468.


 By: Dr John Taddie