Can my DNA Paternity Test be wrong because I’m a chimera?
Human chimeras are a popular topic for TV shows and crime scene dramas. This extremely rare and interesting genetic condition can lead to the question “Can my DNA Paternity Test be wrong because I’m a chimera?”
Named for the mythical monster with a lion’s head, a goat’s body and the tail of a snake, human chimeras have two or more genetically distinct types of cells in their bodies. This is thought to be caused by the absorption, or fusing, of twins before they are born. This would cause the chimera to carry two sets of DNA in their body. One set of their DNA and one that would have been their twin’s DNA. This second set of DNA can show up anywhere in the body. A second, distinct set of DNA may be present in the skin, blood, or even reproductive organs of the chimera. This was what happened in the case of Lynda Fairchild, profiled in the ABC documentary.
She’s her own Twin
Fairchild underwent DNA maternity testing shortly after the birth of her child. Results showed a poor match, as if she was the baby’s grandmother. It was concluded that Fairchild may have been a chimera, her body the result of the fusion of two non identical embryos at the earliest stage of development. Different parts of her body could have come from different cell lines. Further testing indicated that cells taken from her reproductive organs, contained different DNA than those taken from her mouth for the DNA testing and were a match to her children.
Though cases like this are often given a lot of press, their occurrence is very rare. No one knows exactly how many cases of human chimera there are, but most studies cite only 30 reported cases in all of human history.
What does this mean for DNA paternity testing?
An inclusion, or “positive” DNA paternity test shows that an alleged father and the child share the same DNA. Therefore that man is considered to be the biological father. The father’s DNA was passed to the child, and the loci (markers) all match up. It’s virtually impossible (that is, very, very unlikely) that possessing two sets of DNA would make someone appear to be a father when they are not. Matches at all locations indicate a positive paternity test result, even if the father is a chimera.
An exclusion (when a man is not the father of a child) could potentially be affected, by someone being a chimera. It is possible for a chimera to pass one set of DNA on to their child but show a second set of DNA with a cheek swab, as in the Linda Fairchild case. Even so, the child and the father would still likely show a partial match, similar to that of a child and an uncle, since the second set of DNA would be that of the father’s unborn twin.
My husband did but he can’t figure out what the test read and to ask if mother and father were related to each other raised an eyebrow with not understanding the test the mother of the child was with different men, and me being his wife I am the one to help him with his children so we do need to know fully what’s going on,he went through your company for the test but doesn’t have the pass word you were asking about when we were trying to figure things out on the site can he still be helped another way?
After all this 40 YEARS FINALLY I GOT THE UNSWER OF MY LIFE. IM A chimera. I was confuses, mom told me I haf twin but she had a miscarred, and he died or she. I meet my father when I was 11 years old, we look a like , he got 19 kids in total from different women, whe I turn 26 years old my father and I went to do my dna for the emigration, so I can get my papers because he is american And I was born in mexico , my surprice after I I got the results of my dna me and my dad dna came out negative I came on shok and I never understand even my mom and now I understand why after all this year now understan my 2 personalties I got on me boy and girl and now I need to find out where to do me a chimera dna to find out if I carry 2 dna I hope some one can help me aire2puros@hotmail.com
Hi Alex,
I recommend contacting our excellent client support team. They would be more than happy to speak with the lab directors to assist with getting answers you have!. You can contact them at (888) 404-4363 Mon-Fri 9am-8pm EST
I’ve known for some time that Im a chimera, I dont really have questions about my eye color, palm and finger prints changing or how it all seems to be connected to my biological night and day clock, and all of that stuff, but Im fasinated with both medical and psycological impacts of having 2 DNA stuctures. So does anyone know about any research that is being done regarding chimeras?
oh and for Alex, do your personality types switch over at a certain time of day? or is it random?
Im A+ my sons father is O+ but my son is AB+. We have three other children together they are all O+. Before my pregnancy we split up and I sleep with someone else. The other guy is B+ and was DNA tested and he was not his father. How is this possible?
I recently had a paternity test done on my son. I’m A+ and his alleged father is O+ my son is AB+. We had separated in that time I sleep with someone else who was B+. He was tested and DNA was not a match to my son. The now alleged father is the father of my other children who all have O+ blood. How is this possible?
HI Sam,
I am not personally aware of research that is being done on Chimera’s. They are so very rare, only a hand full have been determined since the beginning of time. I would recommend doing some research online to see what you can find. Sorry I cant be of more help.
With an alleged father being O and the child being AB with you A, this is most likely an exclusion. The alleged father with the B blood type is most likely not excluded, however, a DNA paternity test is the only way to know for sure. If the results show that alleged father with the B blood type is excluded and you are sure he is the only other option, I recommend doing a legally collected paternity test with both possible father’s. The legally collected DNA test will ensure that the DNA being tested does in fact belong to the right people and can not be switched at all. You want to test all possibilities.
Hi Sherry,
I hope the last response answered your questions, please let us know if you have any other questions.
I am extremely confused with all this DNA stuff. I have had two of three possibliies tested. The third is dead! I was extremely surprised to find out that the second was not the father 0% chance his family was as well.She looks just like like him. A lot like the rest of the family as well. Not to mention that she has a lot of the same characterics and personalities and has not been arounf the family in 13 years. I am wondering if I should go ahead and ask for a blood test and just chalk up the cheek swab as a bad test. How accurate is it? Please dont judge (Matthew 7).
Confused
Hello So Confused,
I am so sorry, you are in a tough spot. The cheek swabs are 100% accurate as long as the samples given are from the correct people. DNA is the same no matter where it comes from, it can be blood or cheek cells, the DNA is the same. If the alleged father that is no longer available has full siblings, or his parents are available, you can test the child with them as well. When the alleged father is not available the next best option would be to test the child with both of his biological parents. This is known as a Grandparent DNA test. There are other relationship DNA tests also available. We would be more than happy to help you determine if there is another way to test a family member of the third possibility.
Why do people keep insisting on how rare this is??? The number of people I have encountered online who are believed to be chimera are way more then a hand full, plus how does anyone know how rare it is when noone is being tested for this??? Linda fairchilds children were took from her before anyone would even test her….so rare?? Really??? How can u be soo sure??
About 9 to 10 years ago I had my son tested with an alleged dad and it came back negative. There was only one other person I slept with, God is my witness. My son has been tested twice with that alleged dad and it cameback neg. At the age of 19 this was very fustrating and devastating. I know deep in my heart I was not sleeping around like that. The thing that worried me was when I called the dna testing center I will never foget what the lady said to me. I asked why did almost no strains match with the first guy and all but about matched with the second guy? The lady asked was the picture of the second guy the correct person. I said ges. She said the dna looks like this person is related to the child. Help me what should I do? I left it alone at 19yrs old because I was young didnt know what to do. Now im asking God for answers my son has to have a dad. He will be 11 soon and he is asking me about his dad. I dont knos what to tell my son.
Hello Mojahzars,
Let me start by saying a picture of a person does not, and should not influence DNA testing in any way. How people “look” can be deceiving. Only a DNA paternity test will tell you if the alleged father is the actual biological father of a child. At this point I would recommend a legal paternity test. This is where all participants have their DNA collected by a third party collector. This collector is a non interested third party. The collector verifies ID, and takes photos of the participants in most cases. The collector will then send the samples to the lab for testing. This establishes a chain of custody and ensures the samples submitted are from the actual participants. This will help put your mind at ease.
I hope this answers your question, if you do have any other questions please let us know.
I recently tested. My son father n the results came back he wasn’t the father n I know he was the only one iwas with can eating right b4 the swab test effect the results i heard it does
Dear Stuck,
Eating something just before swabbing will not change your DNA. Food will not change or alter a DNA profile. We ask that you dont eat or drink anything before swabbing because we don’t want food particles getting on the swab. The only thing these particles can do is make it more difficult to extract DNA. Because a result was given, you can trust that DNA was collected and tested. Now, this brings me to another question. Did you see the alleged father swab his cheek and place the three swabs in the collection envelope? Did you collect your DNA as well as the child’s DNA and place in appropriate envelopes and mail together? These are important questions that need to be answered. If you used the Identigene test kit, we are more than happy to discuss your result statement as well as help with “next steps”. Our phone number is 888-404-GENE.
my rheumatologist did a dna test on me and genetic says I don’t match myself what does that mean she thought it was interesting but I did not understand what she ment can anyone help.
Dear Charlen,
We would recommend you speak with your rheumatologist about your results. We specialize in paternity testing not genetic testing. Sorry, we couldn’t be of more help.
Hello,
I hope I can get some type of answer on how to go forward. I have a three year old son and a year ago I tested his father three times two times outside of court and one court ordered. Each time he was negative. I did not sleep with anyyY around the time I got pregnant but him. The dna matches 7 out of the 13 markers but he’s been said not to be the father each time. He looks just like him the same and the same dimples and looks like his siblings that was tested and came back to be his kids.I have no idea what to do I have spent so much money already and have come up with no answers to this. If anybody knows of any special testing I could do please give me the information on who to contact I’m completely desperate.
Dear Nymommy,
I’m sorry you have not found the exact answer you are looking for. We can help explain some of your DNA paternity testing questions. When results are received, and the conclusion is “Excluded”, the alleged father and child may still have some markers in common. This does not indicate a biological relationship, it means those specific markers are common among the population. You and I could test together and get some of the same markers, this does not mean we are related, only that we share common DNA. In order for the alleged father to be the biological father the alleged father and child must match at each location (there can be mutations, but we do account for those and there would only be maybe 1 or 2) DNA and similar appearance traits are separate.
It sounds like you have exhausted your DNA paternity testing with the alleged father you mention above. If it were me, I would test anyone else that I had sexual relations with in a two month time period that correlates with my ultrasound due date. As you know, babies can deliver early or late so the best date to work with is the one your OB/GYN gave you after the first ultrasound.