In several divorce cases, there is a question regarding who is the father of a child. Today’s technology can provide the answer to this question. Generally referred to as parentage testing, the most common use is to identify the father, which is paternity testing.
A paternity test can accurately confirm by up to 99.99% that an individual is the father, or it can confirm with 100% accuracy, that he is not. Paternity testing can either be voluntary or by court order.
The most common type of paternity test now uses the DNA of the individuals involved – the alleged father, the baby, and possibly the mother. In the past, other less accurate methods were used, such as ABO blood typing, which is very limited in precision. Today’s technology provides a much more accurate and precise result.
DNA, or deoxyribonucleic acid, is what contains the genetic blueprint of nearly all living things. DNA stores the instructions for the function and development of the living organism and is present in every cell. The part of DNA that contains this genetic information is only one portion of the DNA; other segments are involved in other functions. For the purpose of a paternity test, only the part that carries this information, also known as genes, is used.
In sexual reproduction, the DNA of both parents combines randomly to form a unique group of genetic material. Thus, an individual has DNA that came from both parents. Found in the nucleus of the cell, this genetic material is known as the nuclear genome, or nuclear DNA.
There is also other material in the cell, the mitochondria, which contains genetic material known as the mitochondrial genome. This material comes only from the mother. If this material is used, it can only prove that two people are related through maternal descent. This type of DNA cannot be used to prove paternity of an individual. Nuclear DNA can accurately identify the father and the mother, and is the most common material used in parentage testing.
The mother’s DNA is not required for a paternity test; however, if it is available, the testing may be quicker and provide results that are more accurate. Subtracting the mother’s contribution from the child’s DNA leaves only the father’s DNA for comparison.
Generally, for legal purposes, if a woman is married, the husband is considered the father. If the couple is not married, the father is presumed to be the person listed on the birth certificate. If the mother is married to someone other than the father of the child, it will be presumed the husband is the father.
There are several ways to collect specimens for a paternity test. The parties involved can collect specimens at home. Not legally binding, home tests cannot be used for child custody, or child support purposes. A chain of custody procedure must be followed for a paternity test to be legally binding.
Chain of custody provides documentation of the sample every step of the way, from collection to testing facility. The sample is sealed in tamper-evident packaging. Several laboratories across the country provide paternity testing, and specimens can be collected at several collection sites around the country. The collection site then ships the specimens to the testing facility. Samples for a paternity test need to be collected by an impartial third party, in other words, they cannot be collected at home by the participants themselves.
The least invasive and most common form of paternity testing uses the buccal swab. This consists of a special swab, similar to a cotton-tipped swab. The swab is rubbed against the inside of the cheek to collect loose cells to be used for testing. To ensure the identities of the parties involved, participants must produce a government issued ID, such as a driver’s license. They will also be photographed. There will be a collection fee charged for this, which includes the collection and shipping of the specimen to the testing laboratory.
DNA can also be collected from the baby before birth. This requires an OB-GYN to collect the specimen. Either an amniocentesis or chorionic villus sampling can be performed. Both of these collection methods require a doctor’s consent and pose some risk to the child and/or the mother.
Amniocentesis can be performed between the 14th and 20th weeks of pregnancy. A thin needle is inserted through the abdomen into the uterus. A small amount of amniotic fluid is extracted and used for testing. Possible risks associated with this procedure include miscarriage or harm to the baby, but these risks are small. Side effects of this procedure include vaginal bleeding, cramping or leakage of amniotic fluid.
A chorionic villus sample is obtained by inserting a thin needle into the vagina to collect tissue. The chorionic villi are finger-like tissue attached to the wall of the uterus. The same genetic makeup is contained in the chorionic villi as the baby. This test can be performed between the 8th and 13th week of pregnancy.
Once the samples are collected, they are sealed in the tamper-evident package, and sent to the laboratory for a paternity test. On arrival, laboratory staff confirms the packaging was not tampered with. Generally, different technologists test each person’s sample twice to assure accuracy. The DNA is removed from the cells on the buccal swab and purified. The DNA is added to a mix of chemicals and tested using Polymerase Chain Reaction testing, or PCR. Sixteen specific locations in the DNA are identified and used to create a DNA profile of the individual. The profile of the child is compared to the alleged father’s. This, along with a statistical analysis, will determine the probability of paternity. As stated earlier, a 99.99% probability concludes the person tested is the biological father. A 0% probability confirms that he is not.
The cost for paternity testing varies widely, depending on which type of test is chosen. A home test kit with results may cost between $200 and $400. The cost of a buccal swab test collected at a facility is around $500, plus the charge for collection. For pre-natal testing, there may be an additional fee. This should be considered in the final cost.