Identical twins pointing fingers at each other for paternity testing

The Fascinating Trouble with Twins and DNA Paternity Tests

by HOMEDNA on 07/05/2021

Paternity testing can answer a lot of questions, but some of these questions are trickier to answer than others. Good examples are when DNA paternity testing involves twins, either as children or alleged parents. Identical twin fathers are by far the most difficult to detect due to their indistinguishable DNA samples; rarer cases, such as twin children with two different fathers, are much easier to solve despite their infrequent occurrence.

While reaching conclusive DNA test results when alleged fathers are identical twins is not impossible, the process is outrageously expensive and therefore cost-prohibitive for most folks. As medical advances in the field of genetic testing become more affordable and commonplace, it may become easier to answer these questions of paternity in the future. For now, those answers are fleeting.

Paternity test results with identical twins

There have been many cases in which the alleged fathers are identical twins. The DNA test results are almost always inconclusive since identical twins share almost identical sets of DNA.

Until recently, the consensus has been that identical twins share completely identical DNA, but recent studies show that isn’t necessarily true. Rather than looking at the standard 15 markers analyzed in today’s paternity tests, highly-advanced and impossibly-expensive DNA tests that analyze the entire genome sequence – as many as six billion markers – are able to identify at least a single mutation in one of the identical twins’ genetics that has been passed on to the child (Sapiro). However, DNA tests that are presently accessible to the public do not analyze enough markers to distinguish the two, presenting a serious problem in court cases to establish paternity for child support.

Hopefully, next-generation technology will be able to identify the differences between identical DNA in a way that’s affordable as well as accessible to the general public. Until then, paternity involving identical twins remains unsolvable.

Fraternal twins and different DNA test results

Unlike identical twins, it is possible for fraternal twins to have different fathers, though these cases are extremely rare.

This occurs through a process known as superfecundation, which is the fertilization of two or more eggs from separate acts of intercourse. Studies show that this is possible because the window of time in which a woman is fertile can span from five to seven days (Weller). While an egg only remains fertile for 12-48 hours, sperm can live in a woman’s body for four or five days, thereby expanding the possible time of fertilization (Wikipedia).

This process can only occur with fraternal twins. It is not possible for identical twins to have two different fathers since their identical genetics can only occur when one sperm fertilizes one egg and the resulting cell divides (Worland).

Superfecundation is assumed to happen more often with just one father; however, tests are only able to detect its occurrence when there are two different fathers. The latter group makes up for approximately 2% of paternity suits involving fraternal twins in the United States, generally drawing a lot of attention from the media due to its rarity (Worland).

Even though testing for superfecundation is rarer than administering paternity tests to identical twin fathers, it is a far easier mystery to solve. Provided the fathers in question are not identical twins themselves, modern-day DNA paternity tests can conclusively determine whether fraternal twins have different fathers.

Answering questions of paternity in cases involving fraternal twins

Court cases involving fraternal twin children with different fathers can be resolved with a legal paternity test without complications in the DNA testing process. However, you can always make sure ahead of time with an at-home paternity test from HomeDNA Paternity.

Do you have fraternal twins and suspect there may be two different fathers? Get the answers you need today with our paternity test kit. Click here to learn how it works.

How much does it cost to do a paternity test with twins?

Although you can use one HomeDNA Paternity kit to test twin children, you’re still asking two separate questions:
  1. Is the man tested the biological father of Twin A, and
  2. Is the man tested the biological father of Twin B?
Therefore, although you’re using one kit for the test, two separate lab fees are required. If you’re testing twins, it’s easiest to contact us directly to pay and let us set up the test for you. Just call 888-404-4363 during business hours.

Follow us on Facebook and Twitter! If you have questions about paternity tests or other DNA testing services, please contact our  Client Support Center at 888-404-4363, Mon-Fri  from 8:30 AM to 5:30 PM Eastern Time. Our friendly, expert representatives are ready and happy to help. Get answers anytime by visiting our Help Center. 

Sources Sapiro, Anne. “Understanding Genetics.” Understanding Genetics. Stanford University, 5 Aug. 2014. Web. 21 July 2015.

“Superfecundation.” Wikipedia. Wikimedia Foundation, n.d. Web. 21 July 2015.

Weller, Chris. “NJ Twins Have Two Different Fathers, Court Rules.” Medical Daily. Medical Daily, 08 May 2015. Web. 21 July 2015.

Worland, Justin. “The Science of How Women Can Have Twins With 2 Different Fathers.” Time. Time, 8 May 2015. Web. 21 July 2015.

What a DNA Paternity Test Can and Can’t Tell You

by HOMEDNA on 06/21/2021

When you order a DNA paternity test, what do you expect it to tell you? DNA paternity testing has become so mainstream, and the technology is now so advanced, that some people may expect results to show not only the paternity results, but also specific details and characteristics about each participant. In truth, the reality of what you learn is somewhere in between. Here’s a quick primer on what a DNA paternity test can – and can’t – tell you.

 What a DNA Paternity Test CAN Tell You

 Whether or not a possible father is considered the biological father

This is the whole purpose of using DNA as a testing method for paternity, and it’s by far the most reliable and cost-effective way to determine whether or not a possible father is the biological father. Positive results typically give a probability of paternity of 99.99% (or higher!), and negative results are always 0%. There’s no room for doubt with results like these. When a child’s DNA is tested directly with the possible father’s DNA, a definitive determination one way or the other is almost always the outcome. If you need help analyzing results, our experts are there to help.

A participant’s sex

One of the things checked during a DNA paternity test is whether or not the participant is male or female. This is extremely helpful for a variety of reasons. For example, let’s say someone who orders a test is trying to determine the paternity of their son. When samples are tested, if a technician determines the DNA is from a female instead of a male, the lab can contact the person who ordered a test and ask for a clarification of who the sample belongs to or ask for a sample recollection, if needed. Sometimes DNA gets mislabeled by a client or even contaminated, and so determining a participant’s sex during the testing process is an essential step.

 What a DNA Paternity Test CAN’T Tell You

If a possible father has sent in his buddy’s DNA instead of his own

When you use an AABB-accredited lab like DDC (parent company of HomeDNA Paternity), DNA paternity test results are guaranteed accurate, based on the samples the lab is given. So if a possible father swabs his friend’s cheek for DNA and sends it in under the possible father’s name, the lab assumes on good faith that it is really him and will give report results accordingly. To prevent this kind of fraud, participants (possible father, mother, child) can all collect DNA samples in the same room and send them in together or pay a little extra for a court-admissible legal paternity test, where all collections and submissions are supervised by an impartial third-party.

A participant’s age

Sometimes if there are two possible fathers and those fathers are biologically-related, people think a paternity test can determine which one is the father based on the ‘age’ of the ‘real father’s’ DNA. The truth is it’s not that simple. The only way to determine someone’s age based on their DNA would be to compare a sample taken at birth with a current sample (The Tech). And even that would be an educated guess.

Who the biological father is, if the two possible fathers are identical twins

Identical twins are unique in the population in that they have almost exactly the same DNA. There are 15 genetic markers used for a ‘regular’ test. In order to determine which identical twin is the father, the entire genome sequence for both men would have to be analyzed. This can add up to as many as six billion markers! This makes paternity testing practically impossible and definitely impractical (from a cost perspective) for most people.

If you are the grandparent (or aunt, uncle, brother, sister, cousin, etc.) 

The HomeDNA Paternity home kit is designed for determining the relationship between a potential father and child, which is why the testing fee figures prominently on the box. A paternity test for this price must include the potential father’s samples. If you are trying to connect the dots and determine paternity without the father, you can still use the swabs in the kit to collect DNA from biological family members. Keep in mind, however, that you now are no longer doing a paternity test: you are doing “family reconstruction” testing. This involves testing family members with the child in question to determine a biological relationship and requires much more extensive analysis. For this reason, pricing starts at $399. To see what your options are, we highly recommend you contact us for more information about paternity testing without the father.

>> LEARN MORE ABOUT FAMILY RECONSTRUCTION TESTING

 The Bottom Line

There’s nothing more accurate or cost-effective than a DNA test to determine paternity. It’s just essential to keep in mind that results for this type of test are very specific in their intent: They are designed to tell you whether or not a possible father has a biological relationship with the child in question. Period. If you have other questions that could be answered via DNA, such as whether you are the grandparent, then other types of testing might be the best choice for you.

Follow us on Facebook and Twitter! If you have questions about paternity tests or other DNA testing services, please contact our  Client Support Center at 888-404-4363, Mon-Fri  from 8:30 AM to 5:30 PM Eastern Time. Our friendly, expert representatives are ready and happy to help. Get answers anytime by visiting our Help Center.

 Resources

 “Understanding Genetics.” Understanding Genetics. The Tech Museum of Innovation, 29 Apr. 2004. Web. 02 Dec. 2015. <http://genetics.thetech.org/ask/ask8>.”What Is a Prenatal Paternity Test?” – Health Questions. Gov.UK, 28 July 2015. Web. 24 Nov. 2015. <http://www.nhs.uk/chq/Pages/what-is-a-prenatal-paternity-test.aspx?CategoryID=61&SubCategoryID=615>.

Identigene DNA paternity testing

DNA Paternity Testing Samples: Blood, Spit, or Cheek Swabs?

by HOMEDNA on 03/22/2021

If you’re planning on doing  DNA paternity testing, one of the first questions you think of may be, ‘Is this going to hurt?’  As a top DNA paternity testing lab, we get asked all the time whether there are going to be needles involved. The answer is simply, ‘Probably not.’ The overwhelming majority of post-natal paternity tests are conducted using cheek (or buccal) cells, collected with a painless swab.

Here’s why blood, spit, or cheek cells may be used for DNA tests and also why cheek cells are the method of choice for most DNA paternity testing.

Is Spit Used for DNA Paternity Testing?

Saliva (spit) can be used for paternity testing, but there are some definite pros and cons:

PROS: 

  • It is an excellent source of testable genetic material and a large amount of DNA can be collected in a relatively small sample of saliva
  • It is non-invasive, meaning there are no needles involved and no discomfort

CONS:

  • It is extremely difficult to get a pure saliva sample from a newborn, so the risk of contamination during collection can be high
  • Testing materials (a vial plus specialized liquid for DNA preservation) are expensive when compared to cheek swabs, and that means higher testing costs for the customer
  • If an exclusion (or ‘not the father’) result is obtained and the lab only has one vial of the customer’s saliva to work from, results cannot be confirmed using a separate sample

Why Use Blood for Paternity Testing?

DNA is DNA, so there’s no difference between the genetic material in a blood sample and that collected by other methods. For the most part, DNA collected through cheek swabs or saliva is all that’s needed for fast and accurate paternity testing. But there are times when a blood sample is necessary:

  • For a prenatal paternity test, it is necessary to take a blood sample from the mother. Cells from the fetus free-float in the mother’s bloodstream and so a DNA profile can be obtained from these fetal cells and compared with the possible father’s. The possible father’s DNA is obtained via buccal swabbing
  • In certain cases when the possible father has passed away, a coroner or hospital may have retained a blood card containing the deceased’s DNA. That sample can be tested to help determine paternity

PROS:

  • The risk of accidental sample contamination is extremely low

CONS:

  • Needles are involved, so if you are squeamish or highly-sensitive to pain, this isn’t the optimal choice
  • Blood samples require refrigeration, which is inconvenient at best

Why are Cheek Swabs the Preferred Method for DNA Collection?

When you buy a DNA paternity test kit at a retail location, it comes with three sets of three cheek swabs. Buccal swabs aren’t like regular cotton swabs: they’re specially-designed to effectively collect and trap cheek cells within the fibers.  There are reasons why we use these swabs for most tests instead of any other method:

PROS:

  • Swabs are effective, yet inexpensive. Since three swabs per participant are included in the kit, the lab gets all the DNA it needs to perform the testing and the price of the test is low for the customer
  • It is a non-invasive method of collection: absolutely no needles or pain
  • Unlike collecting saliva, it is easy to collect good DNA samples from the littlest child-even a newborn!
  • Swabs do not require refrigeration. In fact, after samples are collected, they are good for up to six months as long as the swabs are kept in a cool, dry place
  • It is easier and faster for a lab to extract DNA from a cheek swab than from blood

CONS:

  • It is possible for cheek swabs to become contaminated if customers do not handle them per kit instructions. If this happens, however, it doesn’t affect results because it will be caught at the lab level during testing. The customer is then asked to collect new samples before testing resumes.

The Bottom Line

As you can see from these comparisons, the pros of using buccal swabs far outweigh the cons, which is why they are the DNA collection of choice for fast, accurate, and affordable paternity testing.

BUY A PATERNITY KIT NOW

Follow us on Facebook and Twitter! If you have questions about paternity tests or other DNA testing services, please contact our  Client Support Center at 888-404-4363, Mon-Fri  from 8:30 AM to 5:30 PM Eastern Time. Our friendly, expert representatives are ready and happy to help. Get answers anytime by visiting our Help Center. 

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