Twinning Test - Twins

Why do a DNA test between twins?

There are several reasons why twins - twins or parents of twins - want to do a DNA test for twinning.

Curiosity  : beyond the physical traits and a similar character, the twinning test can be wanted for private and recreational purposes of curiosity to determine if brothers and sisters have an identical genetic profile.

Medical Necessity  : it is important to know if the twins have and share genetic and hereditary diseases. In order to better protect yourself if symptoms appear.

It is also interesting to be able to know their compatibility if medical operations are to be planned, such as
  during a blood transfusion or transplant. An identical twin is the ideal candidate to guarantee the success of a surgical intervention, because the risk of rejection of the transplanted organ is minimized since they share the same antigens, 

A medical error : whether during childbirth or by IVF, doing a twinning test can thus confirm whether the two brothers or sisters are indeed from the same fertilization and therefore rule out the slightest medical error in the laboratory or in the maternity ward .

Doubt of paternity : be careful, the twinning test does not make it possible to define the paternity of twins. On the other hand, if the twins are considered to be fraternal twins, it remains possible, but rare, that the paternity of the twins is double. In this case, it is much more reliable to do a DNA Paternity test between the father and the children: Paternity Test 

Can we do the Twinning test remotely?

Yes, you can take saliva samples remotely, before sending them back to the laboratory. In this case, each participant will receive their DNA kit to take the samples at home. Everything must be returned within 3 months of your order, as DNA on mouth swabs only have a shelf life of 3 months. The analysis begins when the laboratory receives all the samples.

How to do a Twinning test in Pharmacy?

It is currently impossible to order a DNA test in pharmacies. Genetic analysis is offered by accredited laboratories that offer their services online or on site.

Frequently Asked Questions

Can we do a Twinning test between brothers and sisters?

It is technically possible for the laboratory to compare the DNA of siblings to determine whether the genetic profile is similar or not. But if you already know that the participants are not from the same multiple pregnancy, then the test will not help you. Because the twinning test does not make it possible to determine a relationship.

If you are looking for a paternal bond between brothers and/or between sisters:
 Sibling Test

It is possible to do a DNA test for twinning at home in a private setting. The order can be placed directly on the internet from your home in order to receive the sampling equipment at home. 

Unfortunately it is still impossible to obtain
a DNA test in a pharmacy , only a laboratory with genetic analysis equipment and accredited by international standards can provide the result for a DNA test.

How to do a DNA test with twins?

The Twinning DNA test can be carried out with:

- Saliva samples (sterile buccal swabs)

- Non-standard samples : Like hair, nails, toothbrush...


Be careful, you must follow the instructions and respect the conditions so that the samples provide enough genetic information for your test.

What type of sample was used for the test?

Consent is the agreement you give to the laboratory to use your DNA for the purpose of doing a genetic analysis . It is mandatory if you want to do a DNA test. Consent can only be given explicitly by an adult and fully lucid person. This agreement must be in writing after receiving informed information of the outcome of the test, by contract or  a consent form .


It is against the law to do a DNA test without the person's consent.

For minors, consent must be provided by one of the legal parents.

What is consent for a DNA test?


Order your DNA test kit on the laboratory website


Receive your DNA kit



Take samples

at home


To return to




Discover your results

by email

DNA test procedure

Identical Twins


Identical twins  result from a single fertilization of an egg by a sperm. The embryo thus formed by this fertilization, then divides in two to generate two fetuses which entirely share the same genes. So they are always of the same sex : two girls or two boys.

This is also called identical or monozygotic twins.

The False Twins


The fraternal twins  arise from a separate double fertilization produced at about the same time. Thus two separate eggs are fertilized by two different sperm and the fertilized eggs then develop separately in the same uterus.

In this construction the twins are dizygotic or fraternal twins and they are similar to all other siblings, which means they only share half of their DNA.

Fraternal twins can be of the same or different sex and most often with dissimilar physical characteristics.

The Results of a DNA Test

- 4  at 7 days using buccal swabs

This period is calculated from the moment your  samples arrive at the laboratory. Transport time is not counted.

What are the analysis times for a Twinning test? 

The authenticity and reliability of the DNA test of  Twinning depends on several factors:

- The quality of the samples

- Laboratory accreditation

How reliable are the results?

The quality of the DNA will depend on the samples taken and the storage of the samples. It is then important to  follow lab instructions  to ensure you receive results.

Accredited laboratories meet the requirements relating to the analysis process, the management of resources and equipment, the impartiality and confidentiality of information. For a Twinning test the laboratory must have
  ISO 17025 accreditation .

The reliability of the result depends on the number of genes compared. All the laboratories offer tests on an average of 15 to 22 genes (Loci STR) to make the comparison between the participants.  

The Twinning test offers a 100% reliable negative result and a 99.9% reliable positive result. 

The results are presented in the form of a table:

- Each  column  corresponding to a participant

- Each line to a compared gene

- The composition of the gene is represented by one or two numbers/per person

Participants must have a similar full genetic profile to be considered identical twins. If the match is perfect on all the lines, the relationship is concluded, otherwise it is rejected. 

How to read the results of a DNA test with Twins?

Genetic laboratory

The choice of laboratory is a very important step when you want to do a parentage test. You should know that each of the laboratories has specific services and depending on your situation it is obvious to make the choice that suits you.

You must choose a laboratory according to:  

- Your family situation and available participants

- The confidence that the laboratory inspires through customer feedback

- The transparency of the company concerning its activities and your expectations

How to choose a reliable Laboratory?

Test de Gémellité
139 €
175 €
195 $ CA
139 €
5 - 7 jours
4 jours
5 jours
4 jours
Participant supplémentaire
+55 €
+ 90 €
+ 175 $ CA
+55 €

The fraternity DNA test makes it possible to define whether two brothers or sisters have both parents in common, only one parent or not at all. This test is useful if the parent concerned is not available.

Sibling DNA Test

Paternity DNA Test

The Paternity test makes it possible to compare the DNA of a child (girl or boy) with the DNA of a presumed father to define a biological relationship or not.

The twins are siblings resulting from a multiple pregnancy .  and  have the characteristic of being born at the same time and very often have a very close physical resemblance . But it would be a mistake to assume that all twins are alike.  

Doing a twinning test between twins or twins makes it possible to realize whether they share an identical genetic profile or not. Confirmation of this comparison can then establish whether they are Identical Twins or Fraternal Twins.

The twinning test can be done with the DNA of 2 or more twins resulting from a multiple pregnancy. The DNA of the parents is not recommended nor taken into account since the comparison is made directly between the genetic profiles of twins or twins.

It is not necessary to carry out the twinning test between brothers and sisters since by deduction they are not from the same pregnancy, so they do not have an identical genetic profile.

The DNA test for twinning is a genetic comparison to establish whether twins have an identical DNA profile or not. This analysis  is able to determine whether twin sisters or twin brothers are identical or fraternal twins.

Moreover, the twinning test does not make it possible to define whether people are twins or simple brothers and sisters. It is important to do this test knowing that the people are from the same multiple pregnancy.

The test can be done after birth with buccal samples only.

What is a Twinning test?

The Participants of the Twinning test