Q: Is DNA paternity testing accurate?

A: The science of DNA testing yields probability results in excess of 99% confirmation that there is a biological relationship while offering 100% certainty to confirm that there is no biological relationship.

Q: What consents are required for paternity testing?

A: There are laws to protect people’s privacy and other rights, which require participants in DNA testing to acknowledge he/she are aware of the process and have agreed to participate. The consents that have to be in place are the consent of any individual whose DNA is to be analyzed. And in the case of a child, consent has to be provided on behalf of the child by their parent, guardian, or anyone who has parental responsibility for that child.

Q: What is the minimum age for testing to be performed?

A: DNA samples can be collected prior to birth and all the way through life. In short, there is no age limitation on DNA testing.

Q: Is a blood sample needed for DNA testing?

A: For most tests NO. DNA samples are easily and painlessly collected by using a large cotton swab, which is run across the inside of the mouth/cheek. The cells containing the DNA analyzed are to be found in cheek cells in the saliva that is absorbed up by the swab.

Specialized prenatal testing is the only test that requires a blood sample.

Q: How can I be sure that I have collected the samples correctly?

A: Don’t worry about making mistakes. All we need you to do when collecting a sample is wiped the inside of the cheek with the swab we provide. If it is done thoroughly you will be sure to collect enough cells for testing to be carried out. So long as you collect the sample from the right people and label the specimens with the right information, it is almost impossible for you to do anything that will affect the results.

Q: Is it necessary for the mother to provide a sample for an accurate result?

A: We strongly recommend that when you order DNA testing that the mother also provide a sample. Her contribution will give us useful genetic data that makes analysis quicker and more straightforward. If for whatever reason no sample is available from the mother it does not prevent us from doing the testing. We are able to carryout the paternity testing and provide conclusive results in any event.

Q: How are the results communicated?

A: Most test results are dispatched 3 to 4 working days after we receive your samples. Some of our more complex tests take a little longer. The results are set out in a written report which gives clear information about whether a biological relationship exists or not.

Q: How and when do I make my payment?

A: When you return your samples with your consent forms, you can send payment then or you may pay over the phone when ordering. If you decide to pay when returning your samples, we accept postal orders, card payments and bankers drafts.

Q: Do you ever provide extra copies of reports?

A: YES. Sometimes we are asked to provide extra copies. This is usually when copies of the report are requested for family members.

Q: What is buccal swabbing?

A: Samples of DNA are collected using buccal swabs. They have the appearance of a large long-handled cotton bud. The tip of the bud is firmer than that of a regular cotton bud. This allows the user to rub off the surface cells inside the cheek easily. The swabs you need are included in the collection kits we send you.

Q: Does analyzing a blood sample give a more accurate result?

A: NO. Your DNA is the same wherever it is found in your body, whether hair follicles, cheek cells or blood – it makes no difference. The accuracy is the same whatever sample type is used.

Q: Does sample collection hurt?

A: NO. The sample collection kit contains the cotton-bud like swabs. They are just rubbed on the inside of the cheek of the person’s whose DNA is to be tested to collect cheek cells. This process is quick and completely painless.

Q: Can I use regular shop-bought cotton buds?

A: NO. The swabs sold in shops are made of cotton. DDC Laboratories buccal swabs are tipped with a fiber called “Dacron”. Dacron is better at wiping up sample cells from which the DNA is extracted. Our swabs make sample collection more reliable, and the DNA testing easier.

Q: Do samples of saliva containing the DNA to be tested have an expiry date?

A: If you allow the swabbed samples to dry, they should be fine. There are no guarantees that a swab will give will a useable sample, but there is no technical date when the sample will stop being valid. However, if you take samples and seal them before they dry, there is a good chance mold will grow on the swabs thereby destroying the sample.

Q: What is a gene pool?

A: A “gene pool” is the totality of genetic data potentially available to a person. Each person receives half of their genetic make-up from their mother, and the other half from their father. By testing both parents and the child in a paternity test, DDC Laboratories can isolate the genetic data contributed by the biological mother. It follows that the remainder of the child’s genetic data must come from the biological father. A comparison of the remaining DNA code from the child with the DNA of the alleged father, allows us to detect whether the person believed to be the father is the actual biological parent of the child.

Q: What are the foundations of population statistics in paternity testing?

A: Every supposed father has a 50/50 chance of being the biological father before the testing is carried out. The paternity index (PI) for each probe used is a likelihood ratio and is defined as the probability that the alleged father contributed the necessary DNA to the child divided by the probability that a random man contributed the necessary DNA to a child. The PI’s for all the probes used are then multiplied together to give a combined paternity index (CPI) value. The probability of paternity (POP) is defined as 1 / (1 +1/CPI) and is multiplied by 100 to give a percentage. If an alleged father’s DNA pattern does not match the child’s, then the PI for that probe is 0.

Q: What is the Paternity Index (PI) and how is it determined?

A: A Paternity Index or PI gives the probability or odds that the alleged father (with a matching DNA segment) is the biological father of the tested child. The occurrence of each DNA segment (a segment is called an “allele”) in the wider population is variable. It depends on how large the allele is, and the race of the person tested as father. The presence and frequency of alleles of different sizes is dependent on what race you are. It follows that knowing the race of the person tested as father is an important factor in the analysis. There are databases available for Caucasian, Black, Hispanic, and Asian races. If people are not sure about their racial heritage, our analysts will use the lowest PI of all available races. It is a prudent and conservative approach to calculating the probability of paternity (POP). The frequency of an allele is pre-determined by how many individuals in that database have an allele of any given size, divided by the total number of people in the database. The resulting frequency is used to calculate the PI.

Q: Does being of mixed race affect the DNA testing?

A: If you have a mixed of multi-racial heritage or you come from a race for which there is no database available, we carry out our calculation using both/all originating races identified to us. For example – both the Caucasian (White) and Black database frequencies will be used. The lowest PI for each probe is used to calculate the Combined Paternity Index (CPI) or POP. Again this gives the most conservative value for the Probability of parentage (POP).

Q: What is a gene mutation? Does it have any consequences for paternity testing?

A: Genes are composed of four chemicals (nucleotides) called adenine, cytosine, guanine, and thymine. The order of these nucleotides in a strand of DNA determines the genetic sequence or code. When there is a gene mutation, one or more of these nucleotides are in a different order than they should be or don’t appear at all in a sequence. Anyone can have a mutation. If a mutation exists in an area of the DNA that is being used for DNA testing, the result will appear not to match between mother and child, or between child and supposed father. However, this will only result in a single exclusion with a given probe, but a complete match on all remaining probes used. If a mutation is suspected, we just extended our testing to by using more probes to confirm the existence of a mutation and thereby rule out an Exclusion. The calculation of the PI and POP includes a mutation frequency for each particular probe. If two mismatches are observed during DNA testing, then exclusions are confirmed.

Q: Can DNA testing take place if a sample can’t be obtained because the person is deceased, missing, or unavailable?

A: There are several ways of addressing this problem. If the person has died, a viable DNA sample might be available if a post-mortem was carried out and the coroner has kept samples; or a useable sample might be obtained if tissue was collected prior to death by the hospital or a laboratory. If there are no samples, other members (parents, siblings, and children) of the deceased person’s family can provide DNA samples. There are several variations of DNA analysis that can establish paternity from those samples.

Q: Has DNA testing been used to help defend or challenge inheritance, wills, or estates?

A: When a will is challenged DNA testing can be used to establish biological relationships. DNA testing can be done as a precaution prior to death so that DNA results are available as soon as a challenge to a will arises, where the claim is from unknown alleged biological relations. Most often this is a precaution adopted by people who are high net worth individuals, or who fear that their wishes will be challenged after death. After death testing, DNA reconstruction, grandparent-age testing, and siblingship testing can also be done to establish biological relationships.

Q: What is the process used in genetic reconstruction, and who needs to provide samples?

A: If one person is dead, or otherwise unavailable to provide a sample, other family members can provide samples to help recreate the DNA of the missing person. As many family members as possible are needed for this process, from parents to full or half siblings to the children of the person in question. The price of this process of genetic reconstruction depends on how many samples are provided for testing.

Q: Please explain grandparentage DNA testing?

A: Samples from grandparents can be very helpful for DNA testing if the supposed parent is unavailable. The supposed parent derived all his genes from his parents i.e. the paternal grandparents. So the grandparents DNA profile will match that of any grandchild with the same degree of accuracy as the absent parent.

Q: Please explain siblingship testing?

A: If the supposed father is absent and no sample is available from him, but there are other children known to be his, those children can provide samples to be tested against the sample from the child in question to discover whether they are full or half siblings. The mother or mothers of the tested children should also provide a sample, because as already explained this simplifies and speeds up the process.

Q: What about DNA testing in adoption cases?

A: We are getting an increasing number of requests to carry out DNA testing in cases where a requirement to match an adopted child with a birth father. Although adoption procedures vary, locating biological fathers to facilitate parental relinquishment has become more important in some places. The paternity testing service we provide supplies proof that the right birth father has been located and is engaged in the proceedings. Grandparents are a great option for DNA testing if the alleged parent is unavailable. The grandparents contributed all the genes to their child, the alleged parent. Thus the grandparents will match their grandchild with the same accuracy as the alleged parent.

Q: Why is there a need for maternity DNA testing?

A: The procedure is very similar to paternity testing. The alleged mother provides a sample, which is compared with a sample from the child. Recent instances of babies being switched at birth have brought about procedures for verification of maternity should this happen. We can conclusively match the mother with her child through DNA testing.