What does it mean probability of paternity?

Each match receives a paternity index (PI) value (last column on the DNA profile). The PI is a statistical calculation that compares the DNA profiles obtained to an untested random individual within the general population, taking the ethnic background of test participants into account. In other words, it is a way of measuring the strength of a particular match based on the relative uniqueness of the allele observed. In the example above, Jane Smith and John Smith share allele 17.3 at marker D16S539. The paternity index for this match is 2.78.

However, if most people have allele 17.3 at this particular location, the PI might be lower. The fact that the two tested individuals match at D16S539 — could indeed be because John Smith is the biological father of the child — but it could also be because most people would match with this allele at this location.

Conversely, if very few people have allele 17.3 at this location because it’s rarer, the PI value would increase.

Once you have your results, the following explanation can be helpful in explaining the meaning of the data. The paternity results are summarized in the report’s interpretation section. The results are explained in one of two ways:

The alleged father is excluded as being the biological father of the child.

The alleged father cannot be excluded as being the biological father of the child, and the probability of paternity is 99.0%. This number can be read as high as 99.9999%.

The "numbers" section of the report reveals the DNA patterns of the individuals tested. People have two genetic markers, or numbers, for each DNA system analyzed. One genetic marker was inherited from the mother, and the other genetic marker was inherited from the father. The order in which the genetic markers appear is insignificant. If the combined paternity index is a non-zero number, there is a match between the alleged father and child. If the combined paternity index is a zero, it is a "non-match" between the alleged father and child. A zero means that the alleged father is excluded as being the biological father of the child. A non-zero number means that the probability of paternity is over 99%.

Problems and/or delays with your DNA results: With any biological testing exceptions can occur. There are a few reasons why your test might not be completed in the typical time.

Hi, Ash. Whether it’s an at-home test or a legal test, the responsibility is on the testing adult to ensure the legal guardian of a minor child has provided consent. For legal tests where chain of custody is maintained and DNA collection is witnessed, the lab must have proof that the legal parent consents to testing. If the proper documentation for the child isn’t provided, testing cannot take place. Because all these safeguards are in place, for legal tests, the mother can request a copy of the results. For at-home tests where DNA is collected by the parties themselves at home, the lab has no way of verifying whether the DNA submitted for testing actually belongs to the names provided by the tested parties. In other words, there is no way to know if the possible father actually submitted the child’s DNA or his friend’s. Therefore, the mother cannot petition to see results. This is one of the main reasons why reports for at-home tests are not court admissible.

Michelle on November 11, 2021 at 11:53 am

Hi. I am a white mother who has a son who is biracial (black & white) .My son who has dark brown hair dark brown eyes had a child with his white girlfriend who also has dark brown hair brown eyes. My grandson is now 4.5yrs old. He has white blonde hair & bright blue eyes & doesn’t look nothing like my son. We have loved & provided for him since the day he was born & while personally, dna makes no difference to me, we recently were sent a Pic of a man that his girlfriend admittedly had sex with around the same time she got pregnant
& was floored by the resemblance..he has light hair & blue eyes.. My grandson does look a lot like him.. however, my son went ahead & did a DNA test at a local facility called “any lab test now” located in Knox TN with only him & my grandson were tested. The results came back 98.4% positive that my son is the father. Is there any possibility that the test could be wrong due to human error? It’s not at all that I want the test to be wrong, bcuz as I said we love this baby & I will be his grandmother no matter what. I just think it’s vital for my grandsons well being later on in life that he knows with certainty who he comes from as I’ve heard horror stories from people who were lied to. That question may sound strange or stupid considering the results we just received but I’m just curious as to if there are situations such as ours where false positives have been reported? Thanks & have a blessed day.

K on February 7, 2021 at 9:45 pm

Hello
My results read 99.999997% cannot be excluded as biological father with a pi of 39,151,316. I only tested father and son and they tested at 20 loci. All were matches. However the other father and mother never tested. If humans share mostly the same DNA and it is impossible to determine if the child in fact received that number from the father instead of the mother at that particular loci how can they gives results with such certainty?
For example a son has 8 as does a father probably the mom does as well but it’s not shown. And most likely the other father has an 8 as well that may belong to him.
It seems that statistics and probability has nothing to really do with exact science. It is making no sense to me. Without all parties how could you possibly conclude this certain allele was passed from father to son?
Can you please clarify. I offer to send my maternal results and companies tell me it’s not necessary. But how

DDC on October 23, 2018 at 4:14 pm

Hi, Amanda. The age of the baby doesn’t affect test results. You didn’t mention if your brother-in-law did a home test or a legal (witnessed) test with court-admissible results, so I’m going to assume you mean a home test. You also didn’t mention whether we did the testing or not, so I’ll assume we did. You can be sure the results are accurate for the samples we were provided. Every test is run twice, each by a separate team, to ensure accuracy once samples arrive at our lab. What we don’t have control over is the DNA collection process. For example, we have no way of knowing if the alleged father really swabbed himself or used someone else’s DNA instead in order to commit fraud. If you’re absolutely sure he submitted his DNA and the baby’s, then there is no question that he’s not the biological father. If you want to do a legal chain-of-custody test just to put the issue to rest once and for all, then that’s an option.

Lisa on May 12, 2021 at 11:34 pm

Hello,

My boyfriend did a paternity test on his alleged child after he was born. The test came back that he was not the father. The mother said it was wrong and refused another test. Eventually, she granted him another one, but she refused to do it infront of him. The test came back inconclusive. After that she sent a forged paternity test. The DNA did not match the original, it was clearly a legal test (which he did not participate in), and the child in the test was a girl not a boy. Finally, she just did another at home test, but this time it came back that he is the father. My boyfriend’s dna is the same as the first test this time. We are planning to have a legal test done, but i am curious to know what could yeild two seperate results?

Thank you!

Natalie on March 17, 2018 at 12:06 pm

Hi , so I did prenatal paternity test when I was close to 11 weeks and it came out my bf was excluded with 8 mismatches , however they rerun it again and I was told that out of 8 mismatches 4 matched and the other 4 seem to be matching too , so I was told to do another blood draw and I told I can ask another guy to send his chick swab and the lab said they don’t need it but will run my boyfriends and after I received a letter that my boyfriend was the father with the probability higher than 99.0% so I don’t know or can I trust this lab now , besides that on a letter wasn’t shown the alleys that matched just written his the father , and the answer how come that first time it was excluded they said it’s because there was not enough fetal DNA signal or too weak so now I’m concerned can I trust the final results ?

DDC on June 20, 2017 at 1:50 pm

Hi, Karla. All DDC testing is done right here at our full-accredited on-site lab. I’ll be happy to address each of your questions:
(1) Results for an at-home test are posted to a secure online account, with the username and password being set up by the decision-maker on the test (usually the person who pays for it). Results are never given over the phone, but a hard-copy of the results can be mailed for a small extra fee. If the test is a legal witnessed one, the process for obtaining results is exactly the same, if it was paid for by a customer. If it was paid for by the courts, results go to the court.
(2) and (3) The difference on the results report between an at-home test and a legal test (where DNA collection and submission to the lab is supervised at an approved facility, such as a clinic, or by an approved party) is that the at-home report does not have names but the legal report does have names. The reason we don’t put names on at-home tests is that we have no way of being sure that the DNA samples submitted actually belong to who test participants say they do. So instead, we assign numbers to identify the samples. Now, when the test is witnessed, IDs for participants are verified and the DNA collector handles all the samples, from collection to mailing, so we can be sure samples are from the correct people listed on the test.
I hope this helps. If you have any other questions, feel free to reach out again!

DDC on July 11, 2017 at 8:18 am

Hi, Whitney. The reason we don’t put names on at-home test results is because we have no way of verifying that the samples submitted really do belong to the participants named on the case. We still put identifiers on the report such as a sample number and the person’s role in the case (child, or alleged father, for example), we just cannot put names. Nevertheless, the results issued are guaranteed accurate for the samples we are given to compare. With at-home testing, the whole process is on the honor system, which is why results aren’t court-admissible. Once an at-home test is complete, you cannot pay extra to have names put on the report because the issue is still the same: not knowing for sure who the participants were.
If you were to pay a little extra do a legal paternity test, then names are put on the report. This is because DNA collection and submission to the lab is witnessed by an approved and trained DNA collector who checks IDs and verifies that the samples for testing belong to the participants whose names are on the envelopes. Because the process is supervised by an impartial witness, names go on the report and results are court-admissible. In your case, if you want names on the report, you’ll have to do a whole new test and arrange for it to be a legal one. I hope this helps! For more details, you can visit the link below and/or call us at 800-681-7162.
https://dnacenter.com/dna-paternity-test/legal-dna-paternity-test/

DDC on September 12, 2017 at 9:08 am

Hi, lbk! Let’s address your questions one by one:
Could there be a false NIPP exclusion? If the test is performed after 8 weeks’ gestation through a highly-accredited facility like DDC, then you can trust results. There are specific metrics we follow to ensure accurate results, and if those metrics are not met, then we do not issue a report. Ours is the only NIPP test on the market that’s been validated and published.
Should I take a post paternity test in hospital? You can do a postnatal test (either an at-home or a legal one) also, but it’s not necessary to confirm results.
Can the cheek swab be contaminated and mess with result? If a swab is contaminated, then the lab will suspend testing, not issue results, and ask for new samples. To ensure the man submits his own sample and not someone else’s, his cheek-swabbing should be witnessed either by the woman being tested (for non-legal testing) or by an approved witness (for legal, chain-of-custody testing with court-admissible results).
Can not having enough DNA for the fetal profile draw an exclusion result, or no result? No. If there is not enough DNA for the fetal profile, then another blood sample will be drawn. No results are issued at all if there is not enough DNA to produce accurate results one way or the other.
Has there been an outcome of no result? Exclusion and not exclusion? I can’t speak for other labs, but we do not issue “inconclusive results.” If there is not enough free-floating fetal DNA to get conclusive results, then we’ll ask for a new blood sample from the mother.
How can I retrieve my profile of mother, fetus, and alleged father? For a postnatal test wherein only about 16 markers per participant is analyzed, we do provide each participant’s file in the report. Because we test thousands of SNPs (genetic data points) for the NIPP test, it is extremely difficult to format all the data, and so we do not make individual profiles available.

kris on November 7, 2017 at 9:54 am

Thanks. I have read your response so many times , and yet I find myself worried daily that when I finally have this baby the test will be wrong and I will lose my husband and family forever. I have faith in God and know that the science behind this test is accurate but cant help but be super worried. Everything is at stake for me.
As mentioned before the test shows that my husband is the father…. 99.9% probability of paternity, he does not even know he was testing for paternity, he thinks we were chosen for a random test , thanks to my Doctor….. so he has no clue that paternity of this child is in question…. can’t wait to have this baby and for all this stress to be over.
i feel like i need constant reassurance that the results of this test is accurate 🙁

DDC on April 9, 2018 at 8:24 am

Hi, David. If there had been any issue with swab contamination or if there had not been enough DNA to test thoroughly, the lab would have suspended testing temporarily and asked for new samples (without issuing results), so your swabbing wasn’t a problem. If you used an accredited lab like ours, you can be sure the results are correct for the samples we were provided. Did you personally witness the swabbing of the child in the test? Are you sure the DNA submitted was the child’s? When doing an at-home test, we always recommend that everyone swab in the same room together, if at all possible. If you did not witness swabbing or live in a different state, you may want to consider doing a legal, witnessed test, for your own peace of mind. If the test you did already was a legal one, then there would be no need to test again.

DDC on August 1, 2018 at 2:41 pm

Hi, Snoop. With a paternity test, the question is more about not how many matches there are, but rather, how many mismatches. As human beings, we all share DNA in common; in fact, if you and I did a relationship test, chances are good we could match up at 7 or 8 or more loci, just because we’re human beings. What matters in trying to establish a father/daughter or father/son relationship is if ALL the numbers match at the same locations for the genes tested. Because a child gets 50% of their DNA from their bio dad, one of the numbers at each location would have to match his if he’s the dad. That being said, there are sometimes exceptions. One or even two mismatches might be acceptable if analysts determine there’s a genetic mutation at a particular locus. Some mutations are common at certain genetic locations for Asian people, for example. That’s why we ask for participants’ race when setting up the test. All of that is factored in when analysts do their calculations to determine a probability of paternity. With today’s technology, getting an “inconclusive” result for a straight paternity test (father/child) doesn’t happen if you test with an accredited lab like ours. We just keep testing more markers, as necessary, to get a conclusive result: either 99%+ if the man is considered the biological father, or 0% if he’s not. Hope this helps!

Anna on September 10, 2018 at 5:56 am

Hello,I would try to make a little summary to get the best answer for my question .I have a booking for a legally prenatal tomorrow morning in London .In the last 24 hours because I experienced huge chest pain I went to the doctor .Long story short it was not the heart who gave me problems it was the lungs ,so they gave me an injection in my belly to stop potential clots to develop in my body (they injected a certain type of coagulant )Because I started to throw away blood in the morning I came back and I need to have like a special X ray to check some things about the lungs ,that will also involve giving some medicine to make lungs more clear at the scan (I don’t know the substance who I will be given yet ).My question is all these coagulants and the other substance can affect my blood test?Can it give me a false positive or a false negative or it will come back worse case scenario not concludent and I will need to retake blood .I would appreciate a lot if you have the amiability to ask a doctor or a person from the laboratory about the effect of coagulants regarding to DNA.Can they affect my DNA in any way?I already paid the deposit and I have a booking tomorrow at 10 in London but if my blood is not concludent I will like to rescheduale .Thank you a lot for your help

ROSAMARIA on September 13, 2018 at 8:45 am

Thank you for the reply, I have been trying to learn more or as much as a can about predisposition for a certain genetic diseases, in particular I am trying to learn if there is a genetic marker or, if there is any genetic predisposition for MCTD, I found genetics to be a as fascinating as challenging, I did not know anything about the process of unveiling the information of DNA, my knowledge about DNA is very limited, I found DDC to be a good source of information, and explain everything in a way that any body can understand the very basics of DNA . Reading other people questions and your answers responded to many of mine, and undoubtedly new questions pop up in my head, It is obvious that DDC is a very dedicated company and conduct everything in a very professional manner.
One last question, It is possible for your company today or in the near future to analyze DNA to see if we carry one o many genetic diseases?
Thank you very much and keep up the great work

LeahMarie on September 17, 2018 at 4:22 pm

Hello I did a prenatal test last month and I tested the guy who I was hoping was not the father and he was indeed excluded. I am just hoping the results are accuracte. I did go through DDC and was sent to a lab here in my city at “Any Lab Test Now”. The only thing is he went on one day and I went the next day so we got our test taken on two different dates but mailed off together. When I first got there they couldn’t find his swabs, then they “found” them. Is there anyway possible that the lab facility could have shipped off another man’s test result that wasn’t my baby’s alleged father? How can I be sure that the swabs that were sent for my baby’s alleged father were sent off with mines. I really want these results to be accurate stating he is NOT the father. I’m just paranoid.

Alina on September 26, 2018 at 1:03 pm

Hello ,I just got the results from DDC yesterday regardless to my prenatal paternity test ,the results is what I expected but the only thing who concernes me and doesn’t let me enjoy my pregnancy is that there is no index or chart .I do think if you reached that conclusion you analysed a chart even if that chart includes 2,688 or whatever how many are loci.My question is :is any way I can get in the Posesion of my detailed chart ,I do belive in DDC and in science but some things you wanna see them with your own eyes especially when it comes to such a big life choice as keeping a baby or not .I am looking for your answer and if you don’t want to send me the report because is too long or I won’t be able to understand it ,I do have a doctor who will be able to understand it and I don’t mind reading 2,688 markers when it comes to something that important .Thank you

Alina on September 27, 2018 at 11:54 am

Why my comment was deleted ?I asked yesterday if I can have a more detailed report of my test and you said to contact that phone number which I did in the morning.The lady over the phone told me she can’t give me the numbers of my test because there are close to 3000 and I said fine ,I do have a doctor who is specialed in dna who I wanna consult so a doctor will be able to explain to me if DDC doesn’t have time for that .My question is how do I get that results ?I did paid for that test and I guess all the numbers who belong to my case ,I have a right to ask about it .This is my life and my pregnancy and I do have the right to see with my own eyes my data .I would like someone to give me an email adress who I can actually get in touch with a person who sends me the report of my test .Thank you

Cherie on December 9, 2018 at 8:36 pm

Is it possible for someone at the diagnostics center to put his DNA up against my DNA to see if and how we are related since you already have our individual DNA results in your systems? In other words, if I called and asked and sent a payment in could this test be run without collecting anymore DNA from he or I? The thing is that; our daughter was diagnosed with a genetic disorder in 2014 of a 10p deletion and 12p duplication and on her test results it states “LCSH throughout the genome indicating possible familial relationship between parents”. Her genetic testing was done with blood via microarray. That is two DNA test that suggests that we could be related which freaks me out. Our family trees are a little hard to track previous to the 1920’s (great grandparents/grandparents) because of poor record keeping due to immigration and just flat out that generational time period, so I can not find the missing link on my own.

Serenity on February 20, 2019 at 10:49 am

Hello,
Back in 2016 I had a paternity test done on my granddaughter. My son passed away, so my other son (his full brother) was tested, along with myself, the mother of the child and the child. My son’s biological father wasn’t available for testing. The agency that did the swab tested my son and I together in one room, while the mom and child were tested in another room. The individual conducting the test filled out the paperwork as if my son being tested was the father (he’s the father’s brother), and his race was marked as “white”, but he’s 1/2 hispanic/latino. When we received the test results it showed 20% probability of my son being the biological father and that the population compared was “white” population. So, is it possible that the results we received are a False NEGATIVE? This little girl is my world, and the only connection I have left to my son. I love her regardless, I’m just wondering if the negligence of the person conducting the test could have resulted in the negative results of the test?

Rita on March 12, 2019 at 9:58 am

Hi I did a DNA test in 2017 but me and my son did it in a lab in Brooklyn by and the father played for it the result take 3 months but a month before the results I got a call from a private number the person say to me I get the date of birth of both you and you son and the name I gave it to them after I said to that person if you have all the information why are you calling it 2 months gone my ? How long those a DNA test take and the father call me with the result saying it’s negative he is not the father and I never get a copied of the results he lives in Texas I have no proof he did a DNA only he have the result I’m thinking to do a test with one of his uncle to get the result can I do that ?

Suresh on March 13, 2019 at 4:28 am

Hi DDC,
There are two Possible fathers involved for Paternity.
Me (Alleged Father 1),My Wife and my child had been tested for 24 Markers Paternity Test. All of my child Markers are inherited from Mother and AF 1.
Test results are The alleged father can not be excluded as being the biological father of the child with Probability of Paternity is >99.99999999% and Combined Paternity Index 38,164,564,715.
There was 2nd test done with Alleged Father 2,Mother and Child had been tested for Paternity test. 15 Markers were not matching out of 24 Markers .
Test results are The alleged father is excluded as being the biological father of the child with Probability of Paternity is 0% and Combined Paternity Index 0.
My Question here is who is the Father of the Child? Whether Alleged Father 1 or Alleged Father 2?
I am the alleged Father 1.Do I need to do some other tests to prove my Paternity. Please help me.

DDC on March 14, 2019 at 3:59 pm

Thanks for the compliment…that’s very kind of you! CPI is obtained by multiplying together the individual paternity index numbers at each genetic locus tested. The individual PI numbers are determined by how frequently that data is seen at that locus for the ethnic population listed. The more rare the data is at that locus, the higher the CPI. It may just be that you and the child have some of the more “commonly seen” data in your profiles, but of course that doesn’t mean you’re any less his/her father. The way you can read your results is: the chance that someone else is the father other than you is 229,542 to 1. The chances of the mother having slept with that one person are pretty dang low. Yes, yours is a lower CPI than 1,000,000 or above, but if you were given a probability of paternity of 99.9% or higher (and I’m assuming you were), that’s the most important part.

DDC on March 27, 2019 at 11:09 am

Oh OK. Those details are helpful, but without seeing the data it’s hard to comment on specifics. But I can say this:
1) Adding the mother can definitely help determine conclusive results or it can make no difference at all
2) Adding the mother can help exclude the father or it can help include the father
3) In our opinion, the lab you used should not have said “determine whether the alleged father can be excluded as the biological father.” They have no way of knowing at this point whether adding the mother will result in an inclusion or an exclusion
4) There is no good reason today that a lab should ever issue an inconclusive result on a paternity test with an alleged father and child. Before issuing any results, they should have asked for the mother’s DNA or tested additional markers until they could give conclusive results

DDC on April 3, 2019 at 10:51 am

Hi, Michael. Without your results in front of me, it’s hard to comment on specifics about whether you’re reading the chart wrong or which comparisons you’re trying to make. I’m assuming you looked through the article you’re commenting on, right? It should have some answers for you. A combined paternity index of 3,841,402 is actually quite high, which strengthens your results. As to whether or not it’s possible for someone else to be the father, paternity-testing is always a matter of statistics, since it’s impossible to test every man in the world with your ethnic background. This is why a probability of paternity can never be 100%. But the odds of someone else being the biological father other than you (the mother sleeping with that 1 in 3,841,402 man who’s not you) are infinitesimally small. If your test had been a legal one with court-admissible results, any court would deem your report as proof of paternity.

Lynn on May 12, 2019 at 12:31 pm

Myself, my son and the alleged father had a paternity test done in 1996. My son’s blood was taken from his little arm–he was 6 months old. The cheeks were swapped from my mouth and the alleged father’s mouth. The results were mailed to each of our home addresses. His result printout stated he was excluded due to 0% probability. My result printout stated that the test was inconclusive due to 50% probability that he was the father. How is it possible that we got two totally different results from the same test? We took the test at the lab that the child support enforcement agency sent us to in our local county. The courts refused to allow us to take another test unless we paid $900 which is $300 per person. We never retested, my son is now 23 years old and a college graduate. Should we try again and do a home dna test? I did test one other man in 1996 because I was dating both men and the result printouts stated 0% for the other man as all three of us were swabbed. I know this is a long question, but please help. Thanks!

Desperate Woman on August 28, 2019 at 2:32 am

Hello DDC, I hope you can answer my questions as I’m borderline crazy and paranoid. I did 2 separate peace of mind paternity tests, one for my oldest child and husband without neither one’s knowledge and on the second one I included my youngest child because that’s how paranoid I am. For their sample on the first test I used a nonstandard sample (toothbrush) for father and child and for myself I was swabbed at the collection facility which is contracted by you guys, so DDC did the testing. They explained about first making sure of the viability of the samples (toothbrushes) and the extraction of enough DNA which they were viable and they got enough DNA. They tested 17 markers and the child and alleged father matched at all loci the CPI is 2,608,735,487 with me included and POP is 99.99999996%. This has been an emotional rollercoaster for me and I’m so paranoid and doubtful so I decided to do a second test because my mind doesn’t stop nagging and telling me it must be a false positive because there’s a second possible father
who is NOT related to my husband in any way. so I did a second test but this time my DNA wasn’t included and since I was so paranoid I also included my second child which I have no doubt about paternity whatsoever, but since my mind is toying with me really bad I did it. This second time I used buccal swabs for both children and a toothbrush for husband without anyone’s knowledge. I used the same collection facility but a different branch location, because I thought they would use a different lab but they are also contracted by you guys, so DDC did the testing again and this time 20 markers were tested for both children and father, they matched at all 20 loci with him giving a POP of child #1( previously tested) 99.999997% and CPI of 4,836,323 child #2 (first time tested) POP of 99.9999998% and CPI of 5,002,930. Are these results correct even though my DNA wasn’t used? I’ve read mother’s DNA has to be included in order to get an accurate result. Also there’s a second possible father for child #1 but he is NO way related to my husband in any way, but like I said I get so anxious and start questioning the results to the point of considering doing a 3rd test with the second man. Can i trust the results of these 2 tests? should I retest again with that other man? I have another question, if my husband were to do an ancestry test with the children will those results show him and the children as first degree relatives? I’m so afraid these paternity tests are positive here but not on an ancestry test. Is saliva DNA the same as cheek DNA? Also one more question, (I’m sorry) is it possible for father and children to have the same pair of alleles on one or two Loci ex.
TPOX- 8|9 • 8|9 • 8|9
D22S1045- 15|16 • 15|16 • 15|16
D2S441- 10|14 • 10| • 10|14
(child1, child2, father) is this something for me to worry about or is it something that can affect the results in anyway? Are both tests reliable even though in the first one (me included) they only tested 17 markers? The loci they didn’t test me on in the first paternity test are THO1, TPOX, D16S539 are these important markers? Will they change the results of the first test had they been used? Please HELP I’m going crazy with all these doubts! I thank you in advance for taking the time to read and answer my questions. Please, please help!

Desperate Woman on August 28, 2019 at 9:26 am

So, what about them having same alleles in those markers?
I read that if the mother’s DNA isn’t used there’s no way to know which allele comes from the father and which one comes from the mother is this true? Also if my husband is NOT excluded as the father does this mean I don’t have to test the other man anymore? And is DNA the same whether is saliva or buccal swab? And the markers I wasn’t tested on will those make a difference at all in the results? Believe me I want these positive results because I dont want my family to be torn apart because of a stupid mistake I made years ago. I had never ever doubted the paternity of my oldest child but one day all of the sudden I did and it’s not a fun feeling. I hope you can elaborate a little more on your answer. I truly appreciate your information.

Robin on October 6, 2019 at 11:29 am

I did the peace of mind Non Invasive Prental Paternity test . I tested at exactly 7 weeks – results came back that excluded the alleged father which is what I was hoping for, but I am so fearful it is not accurate. Even though I ordered the peace of mind test, we “accidentally” went through the entire chain of command at the collections center we went to together. Id’s verified and photo copied by the nurse, all samples signed and sealed by the nurse etc. The chain of command on the test was absolutely followed. Because I am paranoid I am hoping to get court admissible test results. Do I need to do the entire process over? The records will show that the chain of command was absolutely met every step of the way. Had anyone explained to me that my report would not be signed off on or not contain names I would have absolutely chosen the court admissible test from the jump. I asked what the difference was and was told they were exactly the same – just one was official legal documentation which I do not need. I am scared my results are not accurate and really need reassurance.

Hannah on October 24, 2019 at 10:33 pm

I am sure I must be the oldest person who took a DNA test to confirm my father was my father. For many years my sister told me I was adopted. A friend told me about the in home test and I bought one. My father was dying in his 80’s and I am in my 60’s. My parents were married for 55 years, my mother passed away in her 70’s and a couple years ago I sat watching my father die. I had bought the test and when he was sleeping and his mouth was wide open, I swabbed him twice. Days later he died, I mailed off the DNA sample with shaky hands. A week later I returned from his funeral and not long after the results arrived in the mail. My hands were shaking and I thought, why am I doing this, what if he wasn’t my father! I would have been heartbroken and certainly couldn’t ask him questions. I opened it and to my relief he is my father and always will be. I cried like a baby and felt guilty for even wondering, but now I know for sure and if I hadn’t done it, there would never be another chance. So you siblings out there that tell your little brother or sister they are adopted as a joke; it can stick with a child forever. And for those of you who have been teased by a sibling and told your adopted and you are older, I strongly recommend testing to put your mind at ease. Thank you to DDC for confirming my dad was my dad.

DDC on January 24, 2020 at 9:13 am

Hi, John. You’re confusing probability of paternity percentage with the percentage of markers that need to match in order for a man to be considered the biological father. Those are two very different things.
(1) You’re correct that there needs to be 100% matches across the board between a child and the man tested in order for that man to be considered the biological father. The exception to that rule is cases of genetic mutation. In those cases, up to 2 mismatches may occur in the basic battery of 20 loci tested, but mutations are taken into account during analysis and, depending on the data, a man may still be considered the biological father.
(2) 99.9% in an inclusion (IS the father) does not refer to the number of loci that match. Rather, it is the percentage of probability that the man tested is the father, based on the data. It’s obtained through statistical calculations when measured against an unrelated, untested man with the same racial background. Genetic relationship testing is all about statistics. Because it’s impossible to also test every man in the world with the same racial background as the man tested, a probability of paternity can never be 100%. The highest it can ever be is 99.9%+.
Thanks for your questions. I hope this answer is helpful!
P.S. There is no need to test thousands more markers or the entire genome to prove relationship. The 20 markers we test (plus the sex gene) are plenty to determine a father/child relationship.

Jennifer on April 24, 2021 at 11:04 am

Hello, I did A DNA with DDC on December with my daughter and my ex boyfriend (Antony)the results are 99.96% why does it says 96 at the end ? I’m also going to have her tested again with my other ex boyfriend (Juan)cause he just wants to make sure, This results are goin to court also, it’s this lab for sure accurate? So that means Antony it’s her dad since the results are 99.96%? Would I be worried if the lab made a mistake ? Also I want to know if I can take my daughter to go to lab again on a different time or day cause I don’t want Juan to see her he can go on a different day or time,can that be possible? Since this results are going to court also ? The collector took a pic with Antony and my daughter cause we all had went together I just want to know if Juan can go on a different time or date ? Thanks

DDC on July 27, 2021 at 8:47 am

Understanding results for a sibling DNA test is a little tricky, since there can never be a straight “yes or no” answer in this type of relationship testing. Calculations for relationships such as grandparent, avuncular (aunt/uncle), and siblings all involve statistics, and a probability of relationship is given as a percentage in the report:

90% or higher: the relationship is supported by DNA testing
9% – 89%: inconclusive result, and additional parties need to be tested
Below 9%: the relationship is not supported by DNA testing
If a probability of relationship (PRI) of 87.5% is given for your test, the result could be understood as: “There is a an 87.5% probability that the persons tested share a half sibling relationship.” The odds of sharing a parent are 7 to 1.

Delsi, your result is very close to being conclusive, so you may very well be half sisters. Adding more parties to a subsequent test, if possible, would be very helpful. If you’d like to consult with one of our DNA experts, you’re welcome to call 800-929-0847.

Nicole on October 2, 2021 at 9:20 pm

I would like to ask for your advice. I want to do paternity test because I am concern about hospital baby switching issues. For your information, I have done two paternity test (father, mother and child) at two different AABB accredited lab. One lab report shows all locus of us matching but another lab report shows a mismatch between one locus “D22S1045” which is “18, 18” and “15,15” between son and father and “but the probability of paternity is still high which is 99.999999999953 and mention that the reason of mismatch may be due to mutation. However, another lab shows a perfect match between the same locus “D22S1045” which is “15, 18” and “15,15” between son and father. Do I need to be concern about that? They told me maybe it is because of the different kit they are using causing detection of mutated null allele. Do I need to do another paternity test at your lab? I am wondering why there is a mismatch of the same locus on another report but there is a perfect match of the same locus on another different report. I am worried about baby switching issues at hospital and all 24 of the markers of the baby matched with mine and I only have one partner. I would like to ask for your advice. Thanks

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