Parentage - Relationship Division

Frequently Asked Questions

How does DNA paternity testing work?

DNA paternity testing allows the direct examination of the genetic material a child inherits from its biological parents. During the testing process, the child's genetic characteristics are first compared to those of its biological mother. Those characteristics not found in the mother must have been inherited from the biological father. If the alleged father does not contain the genetic characteristics necessary to be the biological father of the child, he is excluded. If the DNA of the tested man does contain those genetic characteristics, then the alleged father cannot be excluded and the probability the man is the true biological father can be calculated.

How does one go about getting a paternity test at UNTHSC?

A standard DNA paternity test requires the collection of a sample from the mother, the child, and the alleged father. Appointments are scheduled at our laboratory weekdays from 8:00 a.m. to 4:30 p.m. Individuals interested in having a paternity test done or who have questions may call 1-800-687-5301. Appointments can also be made on the internet (paternity@hsc.unt.edu). Upon receipt of the email, a paternity coordinator from our office will work with you to set up a date and time for testing. Appointments can also be made for other locations throughout the United States and abroad.

What types of samples are required for DNA paternity testing and where do I have to go to get them collected?

A non-invasive mouth swab called a buccal swab is routinely used to collect samples for DNA paternity testing. The swabs are rubbed gently inside the mouth against the cheek to collect cells which contain the DNA for testing. On rare occasion, a small amount of blood (about one teaspoon) may be collected from participants if extended testing is required. UNTHSC has an extensive network of specimen collection sites. Samples collected throughout the United States are returned to our lab by overnight courier who provides special handling to ensure that specimens arrive safely at our laboratory. Samples collected from other countries are mailed back to our laboratory using the most expedited means available for that location. Not all parties participating in the paternity test need to have their specimens collected at the same place and time. Our customer service representatives will assist you in setting up a convenient appointment to have your samples collected.

Do we need a doctor's request or a court order to have the testing?

No. However, we recommend that all parties consult with a responsible independent person, such as a lawyer or a doctor, who can act as an advisor. Test results may have legal consequences even if no legal action is currently planned. Ultimately the DNA paternity test results can have a significant impact on the child. Independent legal counsel is strongly recommended especially when the mother is not tested.

What do I need to bring and what happens when I come for sample collection?

It is preferable (but not necessary) for the mother, her child and the alleged father to come to the laboratory at the same time. This is recommended so that neither party has any question regarding the identity of the test participants. When you arrive for your appointment, you need to present proper identification required for the chain of custody procedure. Adults are required to bring a government issued photo ID (such as a driver's license, passport, etc.). For children who do not have a photographic ID, parents or legal guardians should bring a birth certificate, social security card or another form of official identification. Children under the age of 18 should be accompanied by a parent or legal guardian with their photo identification. Alleged fathers who are bringing in a child for paternity testing must have a court order, divorce decree, or other official documentation demonstrating their legal ability to present the child for DNA testing which is considered a medical procedure. All participants will be photographed and adults will also be fingerprinted. Samples are collected and labeled in the presence of the test participant who then verifies the specimen is correctly labeled. The process usually takes no more than thirty minutes for the collection of the three individuals. Results are typically available within ten working days unless a rush is requested. (Results from rush cases are available in 5 days or less and are performed for an additional fee).

Can drugs, medications or blood transfusions affect the test results?

Our DNA paternity tests are not affected by drugs or medications. The collection of buccal swab samples for our DNA testing eliminates the concerns that were associated with older forms of paternity tests which required blood samples for the test procedures. With blood samples, recent blood transfusions or a medical procedure called a bone marrow transplant could affect the test results. These concerns are eliminated with the isolation of DNA from the cheek cells collected with our buccal swab collection method.

How old does the child have to be for DNA paternity testing?

DNA paternity testing can be done on the child at any age. A sample from the child can even be obtained by a physician during the delivery of the child so no further inconvenience is imposed on the mother or child.

Can a prenatal DNA paternity testing be done prior to the birth of the child?

Situations exist where it becomes necessary for a mother to determine the paternity of her child prior to its birth. Prenatal paternity testing can be performed on samples obtained by trained medical personnel such as an OB/GYN using a procedure called amniocentesis or chorionic villus sampling (CVS). The amniocentesis procedure is used to obtain fetal cells from the amniotic fluid that surrounds the developing fetus. Amniocentesis is performed in the second trimester, anywhere from the 14th-24th weeks of pregnancy. During this procedure, the doctor uses ultrasound to guide a thin needle to draw out a small amount of amniotic fluid, which contains the fetal cells from which the babies DNA is obtained. An alternative method for obtaining a sample of the child's DNA prior to birth is CVS. This test consists of a doctor using a thin needle or tube guided by an ultrasound, to obtain chorionic villi. Chorionic villi are little finger like pieces of tissue attached to the wall of the uterus. The chorionic villi and the fetus have the same genetic makeup. CVS testing can be done earlier in pregnancy from the 10th-13th weeks. A doctor's consent and assistance is required for prenatal paternity testing. It is the responsibility of the client to seek medical advice concerning the performance of these procedures.

Can a DNA paternity test be performed without the mother?

Yes. If the mother is deceased, is not available, or chooses not to participate, a motherless paternity test can be performed. A motherless paternity test often requires more extensive analysis with additional genetic markers, but produces the same accurate and reliable results. If a man presents a child for a motherless paternity test, we require a court order, divorce decree, or other official documentation demonstrating his legal ability to present the child for DNA testing.

If one participant pays for the testing, why does the other participant get a copy of the test results?

Regardless of which individual pays for the DNA paternity test, all participants who provide a sample will be given a copy of their test results. As an independent testing service, we are neutral and do not restrict reports to any tested party. Our results are confidential and will not be disclosed to outside parties without written consent or a court order.

The alleged father is deceased, what options are available for DNA paternity testing to determine if he was the child's biological father?

A biological sample collected from the alleged father may have been collected prior to his death and may be available. A sample containing his DNA may have been collected and retained by a medical examiner or a coroner if an autopsy had been performed. Alternatively, the deceased alleged father's genetic makeup can be reconstructed using samples obtained from close relatives such as his parents, siblings or other legitimate children. Depending upon what family members are available for testing, each family reconstruction may be unique. Therefore, it is important that interested parties consult one of our laboratory directors for guidance and more information.

What if other possible fathers are related to the man who has been tested?

Brothers and fathers and sons (1st order relatives) share 50% of their genetic material, half brothers and uncle/nephews (2nd order relatives) share 25% of their genetic material and first cousins (3rd order relatives) share 12.5% of their genetic material. Without the laboratory being provided additional information, the statistical calculations in a standard paternity test assumes that other possible fathers are unrelated to the tested man. If there is reason to believe otherwise, this should be brought to our attention as soon as possible. Although it is more difficult to distinguish between close relatives, who are expected to share genetic characteristics, as opposed to unrelated individuals, UNTHSC has the ability to test additional genetic markers so that the DNA tests can almost always distinguish between close relatives such as brothers.

Can DNA paternity testing distinguish who is the biological father if the tested man has an identical twin brother?

No. Identical twins share are the product of one egg and on sperm which after fertilization the embryo will begin to grow and then split into two fetuses. Identical twins have 100% of their genetic markers in common; therefore, no genetic test can distinguish which of them is the true biological father. If either is tested and is not excluded, the other twin is also included as the potential father. Other non genetic factors must be considered by the court in determining the paternity of the child in question.

Can DNA testing resolve issues other than parentage?

Yes. DNA testing can provide information regarding other genetic relationships. Siblingship testing can be used to determine if two individuals are siblings (brothers or sisters) and if they have both (full siblings) or only one parent (half siblings) in common. Twin zygosity testing can be done to distinguish between fraternal and identical twins. Grandparentage testing can be done in the event their son is not available to perform a standard paternity test. Other questions related to kinship should be discussed with one of our directors to explain any potential test limitations or to decide the most appropriate family members to test.